[Figure 1],[Figure 2],[Figure 3]

Diagnosis: Kaposi's sarcoma

[Figure 3] shows H and E stained section of the skin demonstrating an ill-defined vascular proliferation in the dermis. Higher magnification revealed poorly formed vessels and spindled cells dissecting through the collagen, with focal red blood cell extravasation. These findings were consistent with the diagnosis of Kaposi's sarcoma.

Discussion

Kaposi's sarcoma is a multifocal, systemic tumor of endothelial origin with stage dependent characteristic histopathology. It has four clinical variants - classical Kaposi's sarcoma (KS), endemic African KS, KS associated with immunosuppressive therapy, and KS associated with AIDS. KS is the most common cancer occurring in persons with HIV. ^[1]

While exact etiology remains controversial, role of multiple genetic and environmental factors, as well as infective agents has been proposed. The possibility that the human herpes virus 8 (HHV 8) is the inciting factor in KS pathogenesis was considered because of the presence of virus in pathological lesions. Whether this KSHV/HHV 8 is an etiological agent or a cofactor in the development of this vascular neoplasm is uncertain and remains to be proven. KS associated herpes virus (KSHV) can be transmitted sexually and by other means, more often by homosexual than heterosexual activities. Receptive anal intercourse has also been identified as a risk factor. ^[2] Homosexual and bisexual men with AIDS develop KS more frequently than other HIV-infected populations. ^[3] Our patient denied homosexual exposure and he didn't have any history of STD. But in such cases, homosexual activities cannot be ruled out as the patient might not be willing to admit because of the attached stigma.

AIDS KS differs from classical KS by its more rapid course and its rapid multifocal dissemination. Kaposi's sarcoma accelerates the clinical course of HIV infection; moreover, opportunistic infections develop earlier and more often and survival is significantly shortened. ^[4] Kaposi's sarcoma occurs at CD4+ counts of ≤200 cells/mm ³ . ^[5] Lesions starts as small oval violeceous macules that rapidly progress into plaques and small nodules located on multiple sites. Lymph nodes, mucosa, and internal organs like liver and GI tract involvement can occur. Lesions are usually asymptomatic, pain may sometimes be present. Similar AIDS associated KS in a heterosexual male was reported by Kiran Chandan et al. and Rubsamen-Waigmann et al. first documented KS case in an HIV-infected person living in India.

Differntial Diagnosis

The clinical differential diagnosis includes bacillary angiomatosis, lichen planus, drug eruption and coccidiomycosis. Bacillary angiomatosis clinically presents as pyogenic-granuloma-like lesions, subcutaneous vascular nodules, or indurated hyperpigmented plaques, but several morphological presentations in the same patient is possible. All these differentials can be ruled out on the basis of the biopsy.

Histopathology

KS lesions show characteristic pathology of extensive vascular proliferation with presence of solid cords and fascicles of spindle cells arranged between jagged vascular channels. A formalin section can be further tested by the anti-LANA (antibodies to HHV 8 latency-associated nuclear antigen) method for HHV 8.

Treatment

We were not able to offer any treatment to our patient as he didn't come for a follow up after the first visit. Majority of patients with KS respond to local therapy, as many of them have cutaneous lesions amendable to local therapy (cryotherapy, intralesional therapy, and simple excision). Aggressive local therapy (radiation therapy) or systemic therapy (interferon and chemotherapy) may be needed according to stage of the disease. Anti retroviral treatment (ART) is effective and sometimes curative in cases of AIDS KS. ART regimens including PI (Protease inhibitors) regimens and regimens with two NRTI and one NNRTI can induce a complete or partial remission of AIDS/KS. ^[6] ART alone is not sufficient in KS that has already advanced. Combination of chemotherapy or radiation therapy is required in such cases.

KS is chiefly reported in patients with homosexually acquired AIDS, while major route of transmission of HIV is heterosexual; Hence, AIDS related KS are less common in Indian patients.