Tumours And Soft Tissue Sarcoma Paraneoplastic Syndromes Notes

Tumours And Soft Tissue Sarcoma Introduction

A tumour is a new growth consisting of cells of independent growth arranged atypically and serves no function. Broadly classified into:

• Benign
• Malignant

Benign Tumours Papilloma

This is a benign tumour arising from skin or mucous membrane. It is characterised by finger-like projections with a central core of connective tissue, blood vessels, lymphatics and lining epithelium.

Read And Learn More: General Surgery Notes

It can be called a hamartoma or a skin tag. It is an example of the overgrowth of fibrous tissue. It can be pedunculated with a narrow base or broad base.

Papilloma Types

1. Skin Papilloma

• Squamous papilloma occurs in the skin, cheek, tongue, etc.
  • Soft papillomas are squamous papillomas. They are seen in elderly patients on the eyelid as small, soft, brownish swellings.
  • Squamous papilloma can also be congenital, sometimes multiple in number and can be sessile or pedunculated.
• Basal cell papilloma (seborrhoeic keratosis) is seen on the trunk of elderly patients as a brownish elevated patch of skin and gives a semitransparent, oily appearance.

2. Arising from Mucous Membrane of Visceral Organs

• Transitional cell papilloma in the urinary bladder is a cause of haematuria.
• Columnar cell papilloma in the rectum as a cause of mucous diarrhoea.
• Cuboidal cell papilloma in the gallbladder.
• Squamous papillom in the larynx can cause respiratory obstruction.
• Papilloma of the breast (duct papilloma) causes bleeding per nipple.

Papilloma Treatment

Excision is only if the papilloma causes discomfort, or if it is symptomatic.

Papilloma Complications

1. Skin papilloma can get secondarily infected resulting in pain and swelling.
2. Ulceration and bleeding (trauma).
3. Papilloma in the breast, rectum, tongue and gallbladder can undergo malignant change.

Fibroma

Fibroma is a benign tumour, consisting of connective tissue fibres only. Clinically, it presents as a firm, subcutaneous swelling. However, a true fibroma is rare. They are combined with neural elements, muscle tissue or fatty tissue.

Fibroma Types

1. Soft fibromas: Less fibrous tissue
2. Hard fibromas: More fibrous tissue
   • Neurofibroma: Fibroma mixed with nerve fibres
   • Fibrolipoma: Fibroma mixed with fat
   • Myofibroma: Fibroma mixed with muscle fibres
   • Angiofibroma: Fibroma mixed with blood vessels

Fibroma Treatment

They are treated by excision because of the possibility of developing into a sarcoma.

Lipoma Universal Tumour

Lipoma is a benign tumour arising from fat cells of adult type. It is also called a ‘universal tumour’ because it can occur anywhere in the body where there is fat.

• Diagnostic Features of Lipoma
  • Subcutaneous—commonest type
  • Soft to firm lobular swelling
  • ‘Slip’ sign positive—a pathognomonic sign
  • Semifluctuant swelling
  • ‘Smart’ dimple sign on movement of the skin

Lipoma Universal Tumour Types

1. Single Encapsulated Lipoma

• This is a single, soft, slow-growing, painless and semi fluctuant swelling.
• The swelling is soft and may feel cystic with fluctuation. This is also called pseudo-fluctuation because fat at body temperature behaves like a fluid.
• The surface is lobular. Lobulations are better appreciated with firm palpation of the swelling. Due to the pressure, lobules bulge out between the fibrous tissue strands.
• The edge slips under the palpating finger which is a pathognomonic sign of lipoma.
• It commonly presents as a subcutaneous swelling. It is freely mobile. The flank is the commonest site. The shoulder region, neck, back, and upper limbs are the other common sites. Some lipomas from the chest wall can be of large size.
• Dimpling sign: Fibrous bands connect a lipoma to the skin. When the skin moves, a dimple appears on the skin.

2. Multiple Lipomatosis

• Such lipomas are multiple and very often tender because of nerve elements mixed with them. Hence, they are called multiple neurofibromatosis.
• Dercum’s disease is one example of this variety (Adiposis dolorosa) wherein tender, lipomatous swellings are present in the body, mainly the trunk.

3. Uncapsulated Lipoma (Diffuse)

Diffuse variety is a rare type of lipoma. It is called pseudolipoma. It is an overgrowth of fat without a capsule.

Histological Types of Lipoma

• Fibrolipoma: Since fibrous tissue is mixed with fat, lipoma feels hard.
• Neurolipoma: Painful lipoma, because of the presence of nerve elements.
• Naevolipoma: Lipoma is usually relatively avascular but this variety is vascular.

Lipoma Treatment

• An incision is given over the swelling. Dissection is carried out all around, separating it from underlying tissues and it is excised.
• Small lipoma can be removed by incising the skin followed by squeezing the lipoma out (no dissection method).

Lipoma Complications

1. Liposarcoma: The current view is that lipomas are benign and do not turn into malignancy. However, atypical retroperitoneal lipomas and lipoma in the thigh can turn into liposarcoma after many years of growth. Malignancy should be suspected when:

• The swelling grows rapidly.
• It becomes painful due to the infiltration of nerves.
• The swelling becomes vascular and red-coloured with dilated veins over the surface.
• The surface is warm due to increased vascularity.
• Skin foundation or fixation occurs later
• Mobility gets restricted because of infiltration into deeper planes such as muscle.
• Liposarcoma spreads via blood. It rarely spreads via lymphatics. Metastasis in the lung can rarely occur from liposarcoma producing multiple chest secondaries.
• Liposarcoma is treated by wide excision followed by reconstruction either by a split skin graft or by flaps. In the thigh, sometimes radical surgery may amount to compartmental excision. Chemotherapy and radiotherapy can also be used but the benefit is doubtful.

2. Calcification

A 32-year-old man presented with gross swelling of the right leg. He had seen two surgeons earlier who had told him that he had deep vein thrombosis but no treatment was offered. Examination revealed an obvious mass which was palpable in the anteromedial and posterior compartments. MRI revealed an intermuscular mass. At exploration, an intermuscular lipoma weighing 700 g was excised.

3. Myxomatous degeneration: Occurs only in retroperitoneal lipoma.

4. Intussusception—due to submucosal lipoma of the terminal ileum is an abdominal emergency.

5. Saponification.

• Some ‘Rare’ Facts in Lipoma
• • It is rare in children
  • Rarely gives rise to transillumination (if the size is big)
  • Rarely gets infected (because it is relatively avascular)
  • Diffuse variety is rare
  • Neurolipomas are rare
  • Rarely do they turn into malignancy

Neural Tumours Neuroma

They are uncommon benign tumours which arise from the sympathetic nervous system or spinal cord. They can be classified into true neuromas and false neuromas.

True Neuroma

1. Ganglioneuroma: It consists of ganglion cells and nerve fibres of the sympathetic chain. They are slow-growing tumours. When present in the neck as a parapharyngeal mass, it can cause dysphagia. These tumours can occur in the neck, retroperitoneum or mediastinum. Excision of the tumour is the treatment.

2. Neuroblastoma: It consists of poorly differentiated cells. It occurs in young children. It is interesting to know that this tumour can undergo spontaneous regression.

3. Myelinic neuroma: It is very rare. It arises in relationship with the spinal cord made up of myelinic fibres.

Does not contain any ganglion cells. All these three tumours are called true neuromas.

False Neuroma

These tumours arise from the connective tissue of the sheath of nerve endings. They occur following nerve injuries, lacerations or after amputation.

They are of two types:

1. End-neuroma occurs after amputation due to the proliferation of nerve fibres from the distal cut end of the nerve. This produces a bulbous swelling. If it is caught in the suture line or due to pressure on the prosthesis, it produces severe neuralgia pain. To avoid this, when an amputation is being done, the nerve is pulled downwards and cut as high as possible so that it retracts upwards.

2. Lateral neuromas occur due to partial injury to the nerve on the lateral aspect.

Neuroma Treatment

Excision of the neuroma.

Neurofibroma

It is a benign tumour arising from the connective tissue of the nerve sheath. Typically, it produces a fusiform swelling in the direction of the nerve fibres. The tumour contains both neural (ectodermal) and fibrous (mesodermal) elements.

Neurofibroma Clinical Types

1. Single Subcutaneous Neurofibroma (Local) Commonly affects the peripheral nerves such as the ulnar nerve, median nerve or cutaneous nerves. Occurs in
adults.

Single Subcutaneous Neurofibroma Clinical features

• Presents as a painful, subcutaneous nodule.
• Tingling and numbness, paraesthesia in the distribution of the nerve, especially when the nodule is compressed.
• Round to oval swelling in the direction of nerve fibre.
• Smooth surface, with a round border. The swelling moves at right angles to the direction of nerve fibres. Vertical mobility is absent.
• Consistency is firm. Sometimes, it is hard.
• Being a subcutaneous swelling, the skin can be lifted up.

Single Subcutaneous Neurofibroma Treatment

• It is treated by excision.
• In most of the cases, excision is easy as the tumour is well encapsulated.

2. Generalised Neurofibromatosis: von Recklinghausen’s (vR) Disease (Type 1).

• This is an autosomal dominant disorder transmitted by both sexes. The whole body is studded with cutaneous nodules of varying sizes. They are soft and non-tender.
• Coffee brown pigmentation is characteristic of this condition (café au lait spots. Café au lait spots can be associated with the involvement of cranial nerves—8th nerve (auditory nerve) acoustic neuroma—a cerebellopontine angle tumour. Popularly called vestibular schwannoma.
• Fibroepithelial skin tags are often present.
• Type 1 is caused by a gene mutation on chromosome 17.
• The presence of skin pigmentation is an indication of the common neuroectodermal origin of nerve sheath cells and melanocytes.
• Skeletal deformities such as kyphoscoliosis or osteoporosis are common.
• It may be associated with phaeochromocytoma (high blood pressure).
• Sarcomatous changes do occur.

Bilateral vestibular schwannoma or acoustic neuromas are pathognomonic of neurofibromatosis type 2, a syndrome resulting from chromosome 22 mutation. It is also associated with an increased incidence of meningiomas and gliomas.

3. Plexiform Neurofibromatosis (Trigeminal)

• In this condition, the branches of the 5th cranial nerve are commonly affected. It can also involve the peripheries.
• The affected part is grossly thickened due to fibro myxomatous degeneration.
• When it involves the branches of the trigeminal nerve, the following problems can occur:
  • Tingling paraesthesia in the distribution of the 5th nerve, especially ophthalmic division.
  • When it attains a huge size, it can obstruct the vision. As it grows bigger in size, it hangs in front of the neck, as a grossly thickened pendulous fold of skin.
  • Treatment: Very difficult. Excision can be attempted with plastic surgery repair.

4. Elephantiasis Neuromatosa

This condition affects the limbs. It represents an advanced stage of plexiform variety. Gross thickening of subcutaneous tissue gives the appearance of an elephant’s leg. The skin is dry and coarse.

• Complications of Neural Tumours
  • Complications of Neural Tumours
  • Atrophy of muscles
  • Dumb-bell tumours from dorsal spinal nerve root can cause backache or paralysis
  • Acoustic neuroma—deafness
  • Cystic degeneration
  • Sarcomatous change

5. Pachydermatocoele

This refers to the plexiform lesions mainly found in the neck as a thickened, coiled single mass.

Neurilemmoma (Schwannoma)

• This is a benign tumour arising from Schwann cells.
• The commonest site is the acoustic nerve. However, the vagus nerve is the most common peripheral site.
• They can be single or multiple and present with a fusiform swelling in relationship with the nerves.
• They can also arise from a peripheral nerve. Sensory branches are affected more frequently.
• They can also be seen in mediastinum and retroperitoneum.
• They are soft, lobulated, well-encapsulated tumours.
• They are benign and do not turn into malignancy.

Comparison between neurofibroma and schwannoma

Neurilemmoma Treatment

Excision of the tumour can be done without sacrificing the nerves because the tumour is well encapsulated and displaces the nerve.

Hamartoma

It is a tumour-like developmental malformation of the tissues of a particular part of the body wherein it is arranged haphazardly.

• Hamartoma is a Greek word which means fault or misfire. It is not a clinical diagnosis.

A Few Examples of Hamartoma

Haemangioma, neurofibroma, glomus tumour, benign naevus, lymphangioma.

Hamartoma Characteristic Features

• Being a developmental anomaly, they are seen at birth or in early childhood.
• In adults, there is a long history of swelling.
• Being a malformation (not a tumour), it does not have a capsule.
• They can be single or multiple.
• Some may regress as in strawberry angioma.
• They are benign lesions.

Hamartoma Treatment

• Excision is not only curative but also gives a correct diagnosis.
• Care should be taken when it contains vascular tissue such as haemangioma or neural tissue as in cases of neurofibroma.
• The facial nerve and its branches may be damaged while excising hamartomatous lesions over the face.

Chordoma

• Rare tumour
• Remnant of notochord (origin)
• Sacrococcygeal region (common site)
• Resection is difficult, and chances of neurological deficit and bleeding are high.
• Radioresistant

Malignant Tumours Types Of Malignant Tumours

They are of two types: Carcinoma and sarcoma. Carcinoma arises from epithelium—ectodermal, endodermal or mesodermal in origin.

• Sarcomas arise from soft tissues or bone and are derived from mesoblast or mesenchymal tissues.
• It may be observed that mesoderm can give rise to carcinoma and mesenchymal sarcoma also.

Malignant Tumours Pathology

Pathology of tumours

Pathology Spread

1. Local spread: Generally, local spread occurs in adjacent structures. A few examples are given:

• Carcinoma cheek—fixity to mandible Significance: May necessitate removal of mandible along with wide excision.
• Squamous cell carcinoma—fixed to tibia may necessitate an amputation.

2. Lymphatic spread: It is one of the most important features of carcinoma. As you complete reading this book, you will come across many cases and many examples of the lymphatic spread of malignant tumours. A few sarcomas are also spread by lymphatics. Different types of lymphatic spread are given below:

Carcinoma

1. Origin
   • Ectodermal—skin cancer
   • Endodermal—gut cancer
   • Mesodermal—renal carcinoma
2. Types
   • Squamous cell carcinoma
   • Basal cell carcinoma
   • Glandular

• Embolisation: A more aggressive tumour means more aggressive spread—by embolisation wherein nodes can be enlarged in a faraway station, for Example. malignant melanoma.
• Permeation: Refers to tumour cells travelling along the lymphatic vessel, for Example. carcinoma tongue with sub-mandibular node enlargement.
• Retrograde lymphatic spread: When the main lymphatic pathway is blocked retrograde spread can occur and a node in an unusual location may get enlarged, Example. Irish node (left axillary node enlargement in carcinoma stomach).

3. Haematogenous spread: This is the most important method of spread of sarcomas. Also, a few malignancies such as renal cell carcinoma, follicular carcinoma thyroid, carcinoma prostate, carcinoma breast and malignant melanoma commonly spread by blood.

• Bone metastasis and lung metastasis result from blood spread. Bone metastasis can vary from mild form with only bone pain to severe form with quadriplegia or pathological fracture.

4. Transcoelomic spread: Spread through the peritoneal cavity by dislodgment of malignant cells, for Example. Ca stomach with Krukenberg’s tumour—bilateral bulky ovarian metastasis, commonly seen in premenopausal patients.

5. Seeding: A few examples are given below:

• Cancer of the lower lip spreads to the upper lip, also called kiss cancer. Another example is cancer of the vulva.
• Incision and ‘port’ site metastasis (port refers to laparoscopic port).

Comparison of benign and malignant tumours.

Paraneoplastic Syndromes (PNS)

These are interesting syndromes and are listed. Certain cancers produce some specific clinical syndromes (symptom complexes other than cachexia) which cannot be explained by their local.

• Distant spread or by the hormones produced by the tissue of origin of these tumours. These are called paraneoplastic syndromes.
• Just to give an example, hypercalcaemia due to skeletal metastasis from a carcinoma breast is not considered PNS, but if it occurs without skeletal metastasis, it is considered PNS.

Important Features of PNS

• Incidence: 10–15% of patients with cancer
• It may be the earliest manifestation (primary can be occult)
• Bronchogenic cancer and breast cancer are most commonly associated with PNS.
• Hypercalcaemia and Cushing’s syndromes are the most common clinical syndromes associated with PNS.
• PNS can be a major clinical problem and can be treated.

Paraneoplastic syndromes

Aetiology Of Carcinoma In General

1. Tobacco is the most important factor in the development of lung cancer, upper respiratory tract cancer, gastrointestinal tract and genitourinary tract cancer. Carcinoma pancreas is found more commonly in smokers. Passive smokers also have an increased incidence of the development of cancers.

2. Alcohol: Smoking with alcohol increases the permeability of the upper digestive tract mucosa and respiratory mucosa to the carcinogens. Thus, they increase the incidence of cancer. Hepatocellular cancer is commonly found in alcoholic cirrhotic liver.

3. Ionising radiation: Atomic bomb blasts in Japan have definitely resulted in an increased number of cases of breast cancer in premenopausal women and leukaemia in children.

4. Ultraviolet radiation: Causes all types of skin cancers.

5. Genetic causes

Genetic or Defective DNA Repair

1. Xeroderma pigmentosa : Skin cancer
2. Bloom’s syndrome: Acute leukaemia, various cancers
3. Fanconi’s anaemia: Acute leukaemia, squamous cell carcinoma, hepatoma
4. Ataxia-telangiectasia: Acute leukaemia, lymphoma, breast cancer

6. Hereditary causes

• MEN syndrome: Medullary carcinoma thyroid (Multiple Endocrine Neoplasia)
• FPC: Colonic cancer (multiple) (Familial Polyposis Coli)
• Li-Fraumeni syndrome: Familial breast cancer.
• Retinoblastoma.

7. Dietary factors

• Red meat: Carcinoma colon, carcinoma breast.
• Fat: Carcinoma breast, carcinoma colon.
• Smoked, charred fish: Carcinoma oesophagus, carcinoma stomach.

8. Chemicals

• Benzanthracenes: Skin cancer when painted on the skin
• Benzopyrenes: Lung cancer
• β-naphthylamine: Bladder cancer
• Nitrosamines and amides: Cancer stomach
• Aflatoxin B: Hepatocellular carcinoma
• Asbestos: Lung cancer

9. Viral factors

• Human T cell leukaemia virus type 1 (HTLV-1): T cell leukaemia/lymphoma (RNA virus)
• Human papillomavirus (HPV) Cancer cervix, cancer urogenital region
• Epstein-Barr virus: Burkitt’s lymphoma

Soft Tissue Sarcomas(Sts)

These are malignant tumours arising from soft tissues. Thus, they can occur in any part of the body. Examples are given.

Soft tissue sarcoma

Soft tissue sarcoma Introduction

Sarcomas are relatively uncommon tumours accounting for approximately 1% of all adult cancers. These are heterogeneous groups of tumours of mesenchymal cell origin, occurring more commonly in young patients with not a favourable outcome. The overall survival is approximately 40–50% at 5 years.

• These are malignant tumours which are fatal if untreated or mistreated. Most of them occur in young patients as painless lumps. CT scan, MRI and incision biopsy (details later) are key investigations.
• Early diagnosis and curative resection have a major role in the management of soft tissue sarcomas. In addition to TNM staging, pathological grading of the tumour has been included in GTNM staging.

Aetiology Or Epidemiology Of Sts

1. Genetic factors: Genetic mutations or gene rearrangements have been implicated in the pathogenesis of STS. Two genes that are most relevant to soft tissue tumours are the retinoblastoma (Rb) tumour suppressor gene and the p53 tumour suppressor gene. Various familial syndromes are associated with STS such as Li-Fraumeni syndrome, Gardner’s syndrome and von Recklinghausen’s disease. Several oncogenes have been identified.

2. Exposure to radiation: An 8–50-fold increase in the incidence of STS is reported in patients who are treated for cancer of the breast, cervix and ovary by radiation.

3. Neurofibromatosis type 1: Especially mentioned here because it is the only benign tumour progressing to STS. 100% lifetime risk of malignant peripheral nerve sheath tumour, in patients with familial neurofibromatosis, caused by mutations in the NF1 gene.

4. Exposure to chemicals: Thorium oxide, vinyl chloride, and arsenic have been implicated in hepatic angiosarcomas.

5. Trauma: Chronic tissue trauma is blamed as a triggering factor for the development of STS. Others believe that trauma draws the attention of the patient to the STS.

6. Immunosuppression: Kaposi’s sarcoma occurs in HIV or AIDS patients.

• Aetiology of STS—Summary
  • Genetic factors
  • Exposure to radiation
  • Neurofibromatosis (NF-1)
  • Exposure to chemicals
  • Trauma
  • Immunodeficiency
  • Chronic lymphoedema
  • Remember as GENETIC

7. Chronic lymphoedema can give rise to lymphangiosarcoma. Postmastectomy lymphangiosarcoma is called Stewart-Treves syndrome.

Soft tissue sarcomas of (A) trunk and extremity and (B) retroperitoneum

Definition of Primary Tumour (T) AJCC, 8th Edition

• TX – Primary tumour cannot be assessed
• T0 – No evidence of primary tumour
• T1 – Tumour 5 cm or less in greatest dimension
• T2 – Tumour more than 5 cm and 10 cm in greatest dimension
• T3 – Tumour more than 10 cm and 15 cm in greatest dimension
• T4 – Tumour more than 15 cm in greatest dimension

Definition of Regional Lymph Node (N)

• N0 – No regional lymph node metastasis or unknown lymph node status
• N1 – Regional lymph node metastasis
• Definition of Distant Metastasis (M)
• M0 – No distant metastasis
• M1 – Distant metastasis

Definition of Grade (G): FNCLCC = Fédération Nationale des Centres de Lutte
Contre Le Cancer;

• GX – Grade cannot be assessed
• G1 – Total differentiation, mitotic count and necrosis score of 2 or 3
• G2 – Total differentiation, mitotic count and necrosis score of 4 or 5
• G3 – Total differentiation, mitotic count and necrosis score of 6, 7 or 8

AJCC prognostic stage groups for soft tissue sarcoma in the trunk and extremity and retroperitoneum

Aetiology Clinical Features

Sarcomas are rapidly growing vascular growth.

• Typically patients present with a painless lump or swelling in the thigh or forearm.
• When the tumour is increasing in size, size more than 5 cm, deep fascia and painful—suspect STS.

Comparison of carcinoma and sarcoma

Investigations Or Diagnostic Imaging

A few blood tests and cardiac evaluations are done and the ECOG performance score is calculated.

Chest radiography: The presence of cannonball metastasis alters the staging, treatment policy and prognosis.

Investigations Imaging

• CT scan is useful in evaluating retroperitoneal sarcomas. It can define structures, infiltration into neighbouring structures, hydronephrosis, etc. CT can guide a core biopsy also. It is also used to image the chest and pelvis to stage the disease.
• MRI is the investigation of choice when STS occurs in extremities to delineate muscle groups, bones, vascular structures, etc.
• FNAC
  • Useful to detect metastatic disease
  • To detect local recurrence
  • Ideal for superficial lesions
  • Disadvantage: Cannot assess tumour grading. Tissue is not sufficient for diagnostic tests.
• Core needle biopsy: It is the investigation of choice to confirm or rule out the diagnosis. It can give not only the diagnosis but also the histological type and grade. Several scores are added to TNM stagings such as tumour differentiation score, mitotic score and tumour necrosis score.
  • Safe and accurate
  • Tissue is sufficient for grading, electron microscopy and flow cytometry.
  • With CT guidance, a core biopsy can be taken from deeper structures also.
• Incisional biopsy
  • When core biopsy tissue is not adequate, incisional biopsy is indicated. Strict guidelines are to be followed to avoid the risk of tumour seeding.
• PET-CT scan is indicated in high-grade tumours, metastatic disease or before an amputation.

Guidelines while Doing an Incisional Biopsy

• The incision should be oriented longitudinally in STS of extremities to facilitate removal of biopsy site track, scar and tumour en bloc. Do not put a transverse incision.
• Flaps should not be raised
• Perfect haemostasis should be achieved
• Prevent dissemination, avoid crushing of the tissues
• Avoid drain

Investigations Imaging Treatment

The aim is to achieve local control and to treat metastasis including subclinical metastasis, thus trying for a cure.

• Adult sarcomas are best treated by wide excision with negative margin (R–O) resection. However, near the major and minor arteries, the margin need not be wide but it may be a microscopically positive margin.
• Surgery is the first line of treatment varying from a wide local excision to amputation or disarticulation (5%) when it occurs in the extremities. Low-grade tumours can be treated on a 1 cm wide excision of surrounding normal tissue and high-grade tumours by a 2 cm margin.

Surgery for Soft Tissue Sarcoma

• Surgery is the primary and most effective therapy
• Local wide excision with 2 cm of surrounding normal tissue should be removed. 1 cm for low-grade and 2 cm for high-grade tumours.
• Not to dissect along pseudocapsule which is composed of tumour cells.
• If necessary, excision should include nerves and vessels followed by nerve grafts and arterial reconstruction—when they are directly infiltrated. Otherwise, preserve them.
• STS rarely involve bones and skin. Hence, wide resections of these structures are infrequently necessary.
• It should also include previous scars.
• If amputation can be avoided by giving preoperative radiotherapy, it is preferred first. It is then followed by
• wide excision or compartmental excision and postoperative radiotherapy. The dose of pre-and postoperative radiotherapy is 50–60 Gy given in 25 fractions. Brachytherapy is also given.
• Margin negative resection should be the aim

Small tumours less than 5 cm have not been associated with recurrence. Hence, radiotherapy may not be required but if the grade is high, RT is required.

Radiotherapy

• It is not the first modality of treatment for STS.
• Radiotherapy is given after margin-negative resection.
• Surgery + RT has resulted in local control rates up to or more than 90%.
• External beam radiation therapy (electrons, protons or neutrons) is given with a margin of 5 to 7 cm or even more depending on the size of the tumour. The dose is 50 Gy was given in 25 fractions—as a preoperative dose.
• The dose is 60 to 70 Gy for postoperative treatment.
• In brachytherapy, multiple catheters are placed in a tumour resection bed. Catheters are loaded with seeds containing iridium 192.
• The dose of brachytherapy is 42–45 Gy to tumour bed over 4–6 days.
• A short period of treatment time and less systemic toxicity are advantages of brachytherapy.

Tumours do respond to radiotherapy and chemotherapy.

Enneking classification of surgical procedures: Once the specimen is subjected to pathology request should be made to look specifically into the margin status. This is very important. Details are given below. Four types of margin have been recognised.

• If it is intralesional, means the tumour remains—the margin runs through the tumour. If it is marginal, means the surgical plane passes through the pseudo capsule. Pseudocapsule is a reactive zone, hence high chances of local recurrence because tumour satellites may be present.
• When the margin is wide, which means say 2 cm in all dimensions, the recurrence rate is low, because the surgical plane is in the normal plane. Radical, means the tumour is removed including affected compartments and there is a minimal risk of local recurrence.

Role Of Chemotherapy

High-grade tumours have a high potential for metastasis. Hence, combination chemotherapy is to be considered before or after surgery.

• The most favoured combination chemotherapy drugs include Mesna, Adriamycin, Ifosfamide and Dacarbazine (MAID).
• The success rate is around 10–20%. Round cell sarcomas respond better to chemotherapy than spindle cell sarcoma.

Not all sarcomas are chemosensitive. A few details are given below.

Relative chemosensitivity

1. Ewing’s sarcoma
2. Embryonal and alveolar rhabdomyosarcoma

Chemosensitive

1. Synovial sarcoma
2. Myxoid or round-cell liposarcoma

Moderately chemosensitive

1. Pleomorphic liposarcoma
2. Epithelioid sarcoma
3. Pleomorphic rhabdomyosarcoma
4. Leiomyosarcoma
5. Malignant peripheral nerve sheath tumour
6. Angiosarcoma

Chemo-insensitive

1. Dedifferentiated liposarcoma
2. Alveolar soft part sarcoma

Sarcomas that Metastasise to Lymph Nodes

• Rhabdomyosarcoma
• Angiosarcoma
• Clear cell carcinoma
• Epithelioid sarcoma
• Synovial sarcoma
• Remember as RACES

Isolated limb perfusion (like melanoma) with high-dose chemotherapy (melphalan) and tumour necrosis factor-alpha (TNF-α) with hyperthermia to the links can be used by cannulating the artery and vein with a tourniquet.

Prognosis

Almost 80% of STS metastasise to the lungs within 2–3 years of the diagnosis.

• Prognosis depends on metastatic STS, grade of the tumour, size of the tumour, margins after resection and anatomical location.
• If pulmonary metastasis is resectable, 30% survival may be expected at 3 years.

Differential Diagnosis Of Soft Tissue Sarcoma Liposarcoma

It is a malignant fatty tumour.

• Common sites: Proximal extremity (MRI of liposarcoma of thigh), trunk or retroperitoneum.
• They are generally large at the time of diagnosis, for Example. retroperitoneum. It results in gross swelling, which is firm to hard (more than 50% will be of >20 cm size).

Retroperitoneal Sarcoma (RPS)

• Most common RPS is liposarcoma or leiomyosarcoma.
• They constitute 15% of adult soft tissue sarcomas.
• May present as large masses of more than 20 cm at the time of presentation.
• Local recurrence and intra-abdominal spread are more common.
• Progressive abdominal distension, pedal oedema, young age and firm to hard retroperitoneal mass clinch the diagnosis.
• CT scan of chest and abdomen followed by FNAC or truecut biopsy for histology or grade of the tumour.
• Margin negative—complete surgical resection is the treatment of choice.
• Chemotherapy has not been effective against RPS.

The compression of blood vessels may result in oedema of the limbs when it occurs in the retroperitoneum.

• Well-differentiated myxoid liposarcomas are notoriously known to recur many times before spreading to the lungs. Hence, the prognosis is good.
• Dedifferentiated liposarcoma can be distinguished from other poorly differentiated STS subtypes on the basis of MDM2 and CDK-4 immunohistochemistry.
• Pleomorphic and lipoblastic liposarcomas tend to be of higher grade and often present with metastasis.
• MRI followed by wide excision or surgery is the primary treatment.
• They do respond to radiotherapy.

Malignant Fibrous Histiocytoma (MFH)

It is a malignant tumour of mesenchymal tissue (fibrous tissue). This is the recent nomenclature of sarcoma. Fibrosarcoma or pleomorphic rhabdomyosarcomas are included under this.

• Most of the so-called fibrosarcomas are presently included under MFH.
• These are high-grade tumours that lack differentiation.
• It can also arise from bone.
• The MFH: Superficial type rarely metastasises and carries a good prognosis.
• Locations: Retroperitoneum, trunks and limbs (intermuscular septae of adductors, scapulohumeral and pectoral muscles).

Malignant Fibrous Histiocytoma Clinical Features and Treatment

• Common in elderly patients (50 years) but can occur at any age.
• Slow-growing, firm to hard mass with restricted mobility.
• As the tumour is locally invasive, it infiltrates the muscles and adjacent structures. Thus, it can cause muscle weakness or pain, etc.
• Spread: Local spread is common. Distant metastasis by blood is late (lungs). Lymph node metastasis is rare.
• Like other sarcomas, dilated veins, the local rise of temperature, restricted mobility and hardness will clinch the diagnosis.
• MRI is the investigation of choice to know the extent of the disease.
• Margin-negative surgery should be the aim.

Depict types of common sarcomas, wide excision and histological features.

Surgical Procedures Are Done For Soft Tissue Sarcoma

Synovial Sarcoma

Any rapidly growing tumour in the region of the joint or near the tendons in young patients (20–40 years), synovial sarcoma is to be considered.

• Common site: Shoulder, wrist, knee, etc.
• Age: Young between 20 and 40 years.
• Clinical features are similar to the other sarcomas—hard, painful mass.
• In addition to the local and blood spread, it also spreads by lymphatic route.
• Plain X-ray: It may show characteristic calcification.
• It is aggressive, with high rates of recurrence.
• In the G-TNM staging system, they are Grade 3.

Angiosarcoma

• 1 to 2% of soft tissue sarcomas.
• Affects elderly patients.
• They are high-grade and aggressive tumours.
• They arise from skin and subcutaneous tissue rather than deeper tissues.
• Most of them occur in the head and neck, breast and liver.
• Surgery (excision) followed by radiotherapy or combination chemotherapy may have to be given.

Rhabdomyosarcoma

It is the most common soft tissue sarcoma seen in children, even though they are rare (under the age of 15).

• It arises from striated muscle—painless enlarging mass.
• Resection chemotherapy or radiotherapy (combination) is tried depending on location.
• Sites: Head and neck (30%), genitourinary system (25%), extremities (20%).
• All three varieties: Embryonal, alveolar and pleomorphic are considered Grade 3 in GTNM staging. Hence, the prognosis is not good.
• Complete tumour resection should be the aim. Chemotherapy and RT are also used.
• Rhabdomyosarcomas have a high propensity for lymph node metastasis.

Kaposis Sarcoma

Vulnerable section of people include Jews, immunocompromised patients such as transplant recipients and AIDS.

• Typical sites: Legs. Other sites include the chest, arm, and neck in epidemic form (Africa).
• It presents multiple pigmented sarcoma nodules in the leg.
• It is interesting to note that Kaposi’s sarcoma is “not seen” in transfusion-related ‘AIDS ’.
• It manifests with purplish to red subcutaneous nodules in the leg followed by ulceration and bleeding.
• Combination chemotherapy with doxorubicin, etoposide and interferon have been used to control the disease.

Dermatofibrosarcoma Protuberans

Clinically presents as nodular exophytic ‘mass’ lesion—protuberans.

• Locally aggressive tumour which does not metastasise.
• Wide excision should be the aim with a negative margin to prevent local recurrence.
• Mohs’ micrographic surgery such as basal cell carcinoma has been advocated to get a negative margin and thus to get low recurrence rates.
• Has a good prognosis, if treated early.

Malignant Peripheral Nerve Sheath Tumours (MPNST)

• They are malignant forms of benign schwannomas.
• They are aggressive tumours and the local recurrence rate is about 20%.
• Although arising from nerve sheath they are painless at presentation and usually present in the 20–50 years age group.
• MPNST may occur spontaneously or as part of NF-1
• Treatment is similar to other STS subtypes with an aim towards margin negative resection.

Useful Tips In A Case Of Soft Tissue Sarcoma

In undergraduate clinical examination, students are advised to offer soft tissue sarcoma as the diagnosis. When asked about the possible type, they only gave a possible histological type based on the various clinical features mentioned above. Ask the following questions to yourself to get ready for the clinical examinations.

1. Is it soft tissue sarcoma? Tumours arise from soft tissue, dilated veins, reddish skin, increase in local temperature, firm to hard, rapidly growing swelling, with late involvement of skin (carcinoma starts in the skin).

Interesting ‘Most’ to Remember in Soft Tissue Sarcoma

• Most of the soft tissue sarcomas arise de novo.
• Most originate in an extremity (60%).
• The most common soft tissue sarcoma in adults is MFH (28%).
• Most extremity sarcomas (35%) occur in the lower limbs.
• Most occur in men (4 times more common in men compared to women).
• The most common soft tissue sarcoma in children is rhabdomyosarcoma.
• Most of the soft tissue sarcomas metastasise by blood.
• Most of the extremity soft tissue sarcoma metastasises to the lungs.
• Most of the retroperitoneal soft tissue sarcoma metastasises to the liver.
• The most important prognostic factor for soft tissue sarcoma is the size and grade of the primary tumour.
• The most accurate imaging modality for soft tissue sarcoma is MRI.
• The most effective modality of treatment is surgery.
• The most effective chemotherapeutic drugs are doxorubicin, dacarbazine and ifosfamide.

2. What is the age of the patient?

• In children – Rhabdomyosarcoma, Undifferentiated sarcoma
• In 20–40 years – Liposarcoma, Synovial sarcoma, Kaposi’s sarcoma
• In elderly patients – Angiosarcoma, Chondrosarcoma (bone), Fibrosarcoma

3. Which site has it occurred?

• Head and neck – Angiosarcoma, Rhabdomyosarcoma, Osteogenic sarcoma (jaw)
• Distal extremity (limbs) – Synovial sarcoma, Epithelioid sarcoma, Clear cell sarcoma
• Retroperitoneum and mesentery – Liposarcoma, MFH, leiomyosarcoma

4. Has it spread to lymph nodes?

• Rhabdomyosarcoma
• Synovial sarcoma
• Epithelioid sarcoma

5. Has it spread to the lungs or liver?

• Chest X-ray
• Ultrasound

6. Can I preserve the limb? How?

• Wide excision
• Compartmental excision
• Preoperative radiotherapy combined with surgery and postoperative radiotherapy.

Tumours And Soft Tissue Sarcoma Multiple Choice Questions And Answers

Question 1. When do you suspect lipoma turns into liposarcoma?

1. When lipoma gets infected
2. When lipoma causes lymphangitis
3. When it becomes fixed
4. When it undergoes myxomatous degeneration

Answer: 3. When it becomes fixed

Question 2. Intussusception is caused by:

1. Submucosal lipoma
2. Subserosal lipoma
3. Retroperitoneal lipoma
4. Intraperitoneal lipoma

Answer: 1. Submucosal lipoma

Question 3. Myxomatous degeneration occurs only in which lipoma?

1. Retroperitoneal
2. Subfacial
3. Submucosal
4. Subcutaneous

Answer: 1. Retroperitoneal

Question 4. The following is true for von Recklinghausen’s disease:

1. It is an autosomal dominant disorder
2. Skin pigmentation is a feature
3. Café au lait spots are characteristic
4. Does not turn into sarcoma

Answer: 4. Does not turn into sarcoma

Question 5. The following is true for schwannoma except:

1. The commonest site is the acoustic nerve
2. Sensory branches are affected more often
3. Well-encapsulated tumour
4. Highly premalignant tumour

Answer: 4. Highly premalignant tumour

Question 6. The following are radiosensitive tumours:

1. Oral cancer
2. Seminoma testis
3. Carcinoma breast
4. Malignant chordoma

Answer: 4. Malignant chordoma

Question 7. Which one of the following does not have a capsule?

1. Hamartoma
2. Schwannoma
3. Fibroadenoma
4. Branchial cyst

Answer: 1. Hamartoma

Question 8. Which one of the following is commonly associated with paraneoplastic syndrome?

1. Carcinoma stomach
2. Carcinoma colon
3. Carcinoma pancreas
4. Carcinoma lung

Answer: 4. Carcinoma lung

Question 9. Which one of the following conditions is more commonly associated with
paraneoplastic syndrome?

1. Hypernatraemia
2. Hyponatraemia
3. Hypercalcaemia
4. Hypocalcaemia

Answer: 3. Hypercalcaemia

Question 10. Polycythaemia is a paraneoplastic syndrome seen in which condition?

1. Hepatoma
2. Wilms’ tumour
3. Apudoma
4. Renal cell carcinoma

Answer: 4. Renal cell carcinoma

Question 11. Post-mastectomy lymphoedema is called:

1. Stewart-Treves syndrome
2. Bloom’s syndrome
3. Fanconi’s syndrome
4. Sturge-Weber syndrome

Answer: 1. Stewart-Treves syndrome

Question 12. Precautions to be taken while doing an open biopsy in soft tissue sarcoma include the following:

1. The incision should be longitudinal
2. Perfect haemostasis should be achieved
3. Drain should be kept
4. Flaps should not be raised

Answer: 3. Drain should be kept

Question 13. Sarcomas metastasise to lymph nodes includes the following except:

1. Rhabdomyosarcoma
2. Angiosarcoma
3. Synovial sarcoma
4. Liposarcoma

Answer: 4. Liposarcoma

Question 14. The following is true for the treatment of soft tissue sarcomas:

1. Surgery is the best line of treatment
2. Radiotherapy is given after surgery
3. Chemotherapy is also given
4. Radiotherapy is the first line of treatment

Answer: 4. Radiotherapy is the first line of treatment

Question 15. The following is true for the treatment of retroperitoneal sarcoma except:

1. Surgery is the best line of treatment
2. Radiotherapy is extremely helpful
3. Chemotherapy is not very useful
4. Most of them are liposarcoma

Answer: 2. Radiotherapy is extremely helpful

Question 16. Following are high-grade soft tissue sarcomas except:

1. Angiosarcoma
2. Synovial sarcoma
3. Malignant fibrous histiocytoma
4. Liposarcoma

Answer: 4. Liposarcoma

Question 17. The following is true for glomus tumour except:

1. It can turn into a malignant
2. It is an angioneuromyoma
3. It is radio-resistant
4. It is concerned with heat regulation

Answer: 1. It can turn into a malignant