Recognition of Dual or Multiple Pathology in Skin Biopsies from Patients with HIV/AIDS

Abstract

A large percentage of patients with HIV/AIDS will develop dermatological complications. Consequently, all practising clinicians and pathologists in regions with a high prevalence of HIV/AIDS must be familiar with the diverse cutaneous manifestations of the disease. This paper highlights the fact that biopsy material in this clinical context may occasionally reveal more than one pathological process. The potential spectrum includes two or more infections in a single skin biopsy (e.g., herpes simplex and cytomegalovirus infection), neoplastic lesions containing infective organisms (Kaposi sarcoma (KS) and cryptococcosis), dermatoses in association with neoplastic lesions (e.g., KS and interface dermatitis), or more than one dermatosis in a given specimen (e.g., papulopruritic eruption and nodular prurigo). Rare biopsies may even demonstrate triple pathology. The importance of careful examination of skin biopsies in this clinical context is emphasised. Failure to recognise an undiagnosed concomitant opportunistic infective pathogen could have potentially disastrous consequences for the patient.

Figure 1

Papular mucinosis of HIV/AIDS. A mild superficial dermal mononuclear inflammatory infiltrate is associated with subacute eczematous changes in the overlying epidermis (a, b), while the deeper dermis shows separation of collagen bundles by interstitial mucin (c).

Figure 2

Biopsy of a vulval ulcer in a female patient with AIDS. (a) The ulcerated surface epithelium harbours many intranuclear herpes simplex virus inclusions. (b) Concomitant cytomegalovirus infection of an endothelial cell in the inflamed underlying dermis.

Figure 3

Bacillary angiomatosis with incidental cytomegalovirus (CMV) infection (black arrow). Granular colonies of extracellular Bartonella bacilli (white arrows) are present amid the background endothelial cell proliferation and infiltrate of polymorphonuclear leucocytes.

Figure 4

Cutaneous Acanthamoeba infection (black arrow) with concomitant cytomegalovirus (CMV) infection (red arrow) in biopsy from a patient with advanced AIDS and widespread cutaneous ulceration.

Figure 5

Skin biopsy from a patient with AIDS-associated histoplasmosis and concomitant erythema multiforme. A lichenoid reaction is visible in relation to the dermoepidermal interface (a), while the dermis contains conspicuous numbers of Histoplasma capsulatum yeasts (b), whose presence is highlighted with the aid of a Grocott stain (c).

Figure 6

(a) Suppurative folliculitis (black arrow) associated with interface dermatitis (red arrow), the latter ascribed to recently introduced HAART. There is a florid folliculocentric neutrophilic infiltrate (b), with the lumen of the partially disrupted follicle containing both Staphylococcus organisms and Malassezia yeasts (c). Drug-induced pauci-inflammatory interface dermatitis is observed in the neighbouring epidermis (d, e). (By courtesy of Dr. J. Rigby, National Health Laboratory Service and the University of the Witwatersrand, Johannesburg, South Africa.)

Figure 7

(a) AIDS-associated Kaposi sarcoma with concomitant cutaneous cryptococcosis. Cryptococcus neoformans yeasts (including capsule deficient forms) are present amid the background spindle cell proliferation (b), with the mucicarmine preparation (c) highlighting the mucoid capsule around individual yeasts; narrow-based budding is present (inset). The KS lesional cells demonstrate immunoreactivity for both CD31 (d) and human herpes virus type 8 (HHV-8) (e).

Figure 8

(a) Facial Kaposi sarcoma (KS) in an adult man undergoing treatment for pulmonary tuberculosis. A noncaseating granuloma is present within the KS lesion in the lower half of the field (arrow). (b) Detail of the vasoformative KS proliferation. (c) Higher magnification of the tuberculous granuloma. Although acid-fast bacilli could not be demonstrated on Ziehl-Neelsen staining, mycobacterial DNA was detected by PCR. (d) CD31 immunostain highlighting the background KS. (e) The KS lesional cells were also immunoreactive for HHV-8.

Figure 9

Skin biopsy from a patient with HIV-associated acquired ichthyosis and Kaposi sarcoma. The epidermis displays prominent hyperkeratosis (a, b), while the underlying dermis is expanded by a typical plaque-stage Kaposi sarcoma proliferation (c).

Figure 10

(a) Penile squamous cell carcinoma in situ in association with genital Kaposi sarcoma. (b) Detail of the Kaposi sarcoma proliferation replacing the subepithelial stroma. (c) Severe dysplasia involving the full thickness of the overlying surface epithelium.

Figure 11

Skin biopsy demonstrating multiple HIV/AIDS-related pathology, including a superficial vesicle due to varicella-zoster virus infection (a), leucocytoclastic vasculitis in the mid- to upper dermis (b), and incidental Kaposi sarcoma in the deeper dermis (c), the latter confirmed by immunohistochemical staining for HHV-8 (inset). (Reproduced from [1] with permission from BMJ Publishing Group Ltd.).