Inflammation: Definition, Diseases, Types, and Treatment

Inflammatory Diseases

Inflammation of the testis is termed orchitis and the epididymis is called epididymitis the latter being more common. A combination of epididymal-orchitis may also occur. A few important types are described here.

Non-Specific Epididymitis And Orchitis

• Non-specific epididymitis and orchitis, or their combination, may be acute or chronic. The common routes of spread of infection are via the vas deferens, or via lymphatic and haematogenous routes.
• Most frequently, the infection is caused by urethritis, cystitis, prostatitis and seminal vesiculitis. Other causes are mumps, smallpox, dengue fever, influenza, pneumonia and filariasis.
• The common infecting organisms in sexually-active men under 35 years of age are Neisseria gonorrhoeae and Chlamydia trachomatis, whereas in older individuals the common organisms are urinary tract pathogens like Escherichia coli and Pseudomonas.
  • Morphologic Features Grossly, in the acute stage the testicle is firm, tense, swollen and congested. There may be multiple abscesses, especially in gonorrheal infection. In chronic cases, there is usually a variable degree of atrophy and fibrosis.
  • Histologically, acute orchitis and epididymitis are characterised by congestion, oedema and diffuse infiltration by neutrophils, lymphocytes, plasma cells and macrophages or the formation of neutrophilic abscesses.
  • Acute inflammation may resolve or may progress to a chronic form. In chronic epididymal-orchitis, there is focal or diffuse chronic inflammation, the disappearance of seminiferous tubules, fibrous scarring and destruction of interstitial Leydig cells.
  • Such cases usually result in permanent sterility.

Read And Learn More: Systemic Pathology Notes

Granulomatous (Autoimmune) Orchitis

• Non-tuberculous granulomatous orchitis is a peculiar type of unilateral, painless testicular enlargement in middle-aged men that may resemble a testicular tumour clinically.
• The exact aetiology and pathogenesis of the condition are not known though an autoimmune basis is suspected.

Morphologic Features Grossly, the affected testis is enlarged with thickened tunica. The cut section of the testicle is greyish-white to tan-brown.

• Histologically, there are circumscribed non-caseating granulomas lying within the seminiferous tubules.
• These granulomas are composed of epithelioid cells, lymphocytes, plasma cells, some neutrophils and multinucleate giant cells.
• The origin of the epithelioid cells is from the Sertoli cells lining the tubules.
• The tubules show peritubular fibrosis which merges into the interstitial tissue that is infiltrated by lymphocytes and plasma cells.

Tuberculous Epididymo-Orchitis

• Tuberculosis invariably begins in the epididymis and spreads to involve the testis. Tuberculous epididymal-orchitis is generally secondary tuberculosis from elsewhere in the body.
• It may occur either by direct spread from genitourinary tuberculosis such as tuberculous seminal vesiculitis, prostatitis and renal tuberculosis, or may reach here by haematogenous spread of infection such as from tuberculosis of the lungs.
• Primary genital tuberculosis may occur rarely.

Morphologic Features Grossly, discrete, yellowish, caseous necrotic areas are seen.

• Microscopically, numerous tubercles which may coalesce to form large caseous masses are seen.
• Characteristics of typical tubercles such as epithelioid cells, a peripheral mantle of lymphocytes, occasional multinucleate giant cells and central areas of caseation necrosis are seen.
• Numerous acid-fast bacilli can be demonstrated by Ziehl-Neelsen staining.
• The lesions produce extensive destruction of the epididymis and may form chronic discharging sinuses on the scrotal skin.
• In the late stage, the lesions heal by fibrous scarring and may undergo calcification.

Spermatic Granuloma

Spermatic granuloma is the term used for the development of inflammatory lesions due to the invasion of spermatozoa into the stroma. The spermatic granuloma may develop due to trauma, inflammation and loss of ligature following vasectomy.

Morphologic Features Grossly, the sperm granuloma is a small nodule, 3 mm to 3 cm in diameter, firm, white to yellowish-brown.

• Histologically, it consists of a granuloma composed of histiocytes, epithelioid cells, lymphocytes and some neutrophils.
• Characteristically, the centre of spermatic granuloma contains spermatozoa and necrotic debris. The late lesions have fibroblastic proliferation at the periphery and hyalinisation.

Elephantiasis

• Elephantiasis is the enormous thickening of the scrotal skin resembling the elephant’s hide and results in the enlargement of the scrotum.
• The condition results from filariasis in which the adult worm lives in the lymphatics, while the larvae travel in the blood.
• The most important variety of filaria is Wuchereria bancrofti. The condition is common in all tropical countries. The vector is generally the Culex mosquito.
• The patients may remain asymptomatic or may manifest with fever, local pain, swelling, rash, tender lymphadenopathy and blood eosinophilia. An asthma-like respiratory complaint may develop in some cases.

Morphologic Features Grossly, the affected leg and scrotum are enormously thickened with the enlargement of regional lymph nodes.

• The affected area of the skin may show dilated dermal lymphatics and varicosities.
• Histologically, the changes begin with lymphatic obstruction by the adult worms.
• The worm is alive, dead or calcified form may be found in the dilated lymphatics or in the lymph nodes.
• Dead or calcified worm in lymphatics is usually followed by lymphangitis with intense infiltration by eosinophils.
• Sometimes, granulomatous reactions may be evident. In advanced cases, chronic lymphoedema with tough subcutaneous fibrosis and epidermal hyperkeratosis develops which is termed elephantiasis.

Miscellaneous Conditions

Torsion Of Testis

• Torsion of the testicle may occur either in a fully-descended testis or in an undescended testis. The latter is more common and more severe.
• It results from sudden cessation of venous drainage and arterial supply to the testis, usually following sudden muscular effort or physical trauma.
• Torsion is common in boys and young men.

Morphologic Features: The pathologic changes vary depending upon the duration and severity of vascular occlusion.

There may be coagulative necrosis of the testis and epididymis, or there may be haemorrhagic infarction. The inflammatory reaction is generally not so pronounced.

Varicocele

• Varicocele is the dilatation, elongation and tortuosity of the veins of the pampiniform plexus in the spermatic cord. It is of 2 types: primary (idiopathic) and secondary.
• The primary or idiopathic form is more frequent and is more common in young unmarried men.
• It is nearly always on the left side as the left spermatic vein enters the renal vein at right angles while the right spermatic vein enters the vena cava obliquely.
• Also, the longer length of the left testicular vein, the nutcracker phenomenon of the superior mesenteric vein, and the loaded sigmoid colon pressing the left vein are other possible explanations.
• The secondary form occurs due to pressure on the spermatic vein by enlarged liver, spleen or kidney. It is commoner in middle-aged people.

Hydrocele

• A hydrocele is an abnormal collection of serous fluid in the tunica vaginalis. It may be acute or chronic, congenital or acquired.
• The usual causes are trauma, systemic oedemata such as in cardiac failure and renal disease, and as a complication of gonorrhoea, syphilis and tuberculosis.

• The hydrocele fluid is generally clear and straw-coloured but may be slightly turbid or haemorrhagic. The hydrocele sac may have a single loculus or may have multiple loculi.
• The wall of the hydrocele sac is composed of fibrous tissue infiltrated with lymphocytes and plasma cells.