Pathology

II. Infectious Diseases

Objectives:

After completing this tutorial the student will be able to:

• list the infectious diseases involving the vulva
• specify the etiologic agents and mode of transmission
• describe/recognize clinical lesions
• describe/identify characteristic histologic features
• state clinical behavior/complications

1. Condyloma acuminatum (Genital or Venereal warts)

Condyloma acuminata are sexually transmitted warty lesions caused by the human papilloma virus (HPV), mainly types 6 and 11 but may be caused by type 16/18. Areas involved include the vulva, vagina, cervix, urethra, anal canal, perineum and perianal skin. The lesions may be flat but are usually exophytic, solitary but more frequently multiple and focal or extensive.

Note the raised, fleshy excrescences that fill and obscure the vulva and extend to involve the perianal skin (exophytic and extensive).

Question: Flat condylomas are more frequent than exophytic condylomas in which of the areas listed above?

Question: What is the likely implication of finding vulvar condyloma acuminatum in a child?

• Histology

The virus invades the basal cells of the stratified squamous epithelium and establishes a virus-driven stimulation of cell replication. There is thus thickening of the stratified squamous epithelium (acanthosis) with widening and elongation of the rete ridges (papillomatosis). There may be a thickened keratin layer (hyperkeratosis) which may contain pyknotic nuclei (parakeratosis). The virus-infected keratinocytes have a distinct morphology referred to as koilocytosis. The koilocyte (infected cell) is a vacuolated keratinocyte containing a pyknotic nucleus surrounded by a halo. These cells serve as markers of HPV infection and are produced by viral cytopathic effect.

Flat condyloma. Note the circled koilocytes, one of which is being exfoliated.

Exophytic condyloma

• Clinical behavior

The disease runs a long, protracted course. The outcome may be influenced by immunologic factors. In the immunosuppressed, the lesion can progress to dysplasia, and possibly invasive squamous cell carcinoma.

Question. How is condyloma acuminata treated?

2. Herpes genitalis

This is a sexually transmitted disease caused by Herpes simplex virus (HSV) types II in 90% and I in 10% of cases.

• Clinical appearance

The lesions appear as multiple, small, painful vesicles that rapidly erode into shallow, painful ulcers. Similar lesions may occur in the vagina, cervix, urethra, bladder and anus.

Herpetic vesicles on vulva and perineum.

• Histology

There is necrosis of infected cells with formation of intraepithelial vesicles and skin ulceration.

Suprabasal intraepidermal vessicle filled with serum and degenerated epidermal cells.

Cells at the margins of vesicles show characteristic viral cytopathic effect including nuclear homogenization, large eosinophilic intranuclear inclusions, and formation of multinucleated giant cells.

Multinucleated giant and single cell containing large intranuclear inclusion.

• Clinical behavior

In the immunocompetent host, the lesions heal in about 2 weeks. The virus establishes latent infection in sensory ganglia and reactivation results in recurrent episodes of disease activity.

Question: What is the likely clinical course of the disease in an individual with AIDS?

Question: What conditions may cause reactivation of a latent infection?

Question: What complications may arise during pregnancy?

 

3. Syphilis

Syphilis is a venereal disease caused by the spirochete Treponema pallidum.The disease is acquired through sexual contact with an infected person.

• Clinical appearance

The organism produces a primary lesion called the chancre at the portal of entry. The chancre is a painless, indurated, shallow ulcer accompanied by lymphadenopathy. The ulcer heals spontaneously within 6 weeks and typically does not leave a scar.

The secondary lesion, which is highly infectious, appears as papules called "condyloma lata" on the vulva associated with rash on the palms and soles.

The tertiary lesion, referred to as the gumma, rarely involve the vulva.

• Histology

The primary chancre is characterized by ulceration of the epidermis accompanied by chronic inflammation with large numbers of plasma cells. Arteritis with severe perivascular inflammatory response is present. The condyloma lata show similar histological features but there is marked epithelial thickening and hyperkeratosis with no ulceration.

• Diagnosis

This requires a high level of clinical suspicion. The histological are non-specific and organisms can be hard to detect in histological sections. Serum expressed from the primary chancre or condyloma lata can be examined for the presence of spirochetes. Serologic studies of antibody to treponemal antigen are commonly used for diagnosis.

• Clinical behavior

About a third of patients with primary syphilis will develop spontaneous remission of the disease. The remainder of untreated cases will progress to the tertiary stage.

• Complications

Cardiac and central nervous system involvement occurs in tertiary syphilis.