Histological aspects of sexually transmitted genital lesions.

Occasional biopsies of genital lesions due to chancroid, secondary syphilis (the condyloma latum) and granuloma inguinale are encountered in routine histopathological practice. These lesions have specific microscopical appearances enabling a confident, or at least a presumptive, diagnosis to be made in most cases, yet the value of biopsy in the diagnosis of these diseases is not generally appreciated. The ulcer of chancroid shows three zones--a narrow superficial zone of degenerate leucocytes and fibrin, a broader middle zone with characteristic vascular changes, and a deep zone in which there is a plasma cell and lymphocyte infiltrate. The condyloma latum shows hyperplasia of the epidermis which is infiltrated with polymorphonuclear leucocytes in addition to the mononuclear infiltration of the dermis. Large numbers of spirochaetes are found in the area of the polymorph exocytosis of the epidermis. The inflammatory infiltrate of granuloma inguinale consists of a neutrophil and plasma cell infiltrate with moderate numbers of large mononuclear cells in which there are one or more vacuoles containing Donovan bodies.