Kaposi sarcoma in HIV ‐negative men who have sex with men

DEAR EDITOR, Kaposi sarcoma (KS) is an angioproliferative malignancy, subclassified into classic, African (endemic), AIDS-related and iatrogenic type. A new subgroup of patients with KS has been increasingly recognized – men who have sex with men (MSM), but who are HIV-seronegative and have no identifiable immunodeficiency. Herein, we describe a series of patients who do not fit into the current classification system for KS. Between 1997 and 2011, eight HIV-seronegative MSM patients with histologically confirmed KS were identified from the personal archives of the authors (one patient from Lewisham Hospital; seven from Chelsea and Westminster Hospital). The median age of the patients was 53 years (range 37–65). Seven (88%) patients were white British, and one patient was of Hong Chinese descent. Four (50%) patients were skin type I, three (38%) were skin type II and one (12%) was skin type IV. The number of KS lesions varied from one to 50, with a median of four lesions. Two (25%) patients had only one KS lesion. Four (50%) patients had KS lesions confined to their lower limbs, and three (38%) patients had both upper and lower limb involvement. One patient had a single lesion located on the temple. At the time of KS diagnosis, two (25%) patients had KS-associated herpesvirus (KSHV) viraemia, with detectable plasma KSHV DNA (570 and 700 copies mL , respectively). Immunohistochemistry for KSHV latent nuclear antigen 8 was positive for all cases. The histological grade of KS for six (75%) patients was of nodular grade; one patient had angiomatoid grade KS; and one patient had an unspecified grade of KS. The primary therapy for six (75%) patients was surgical excision. For the remaining two patients, the KS was treated with radiotherapy (n = 1) and systemic chemotherapy (n = 1). After a median follow-up of 3 7 years (0 2–15), all patients were alive. Only a few sporadic reports regarding KS in HIV-seronegative MSM have been published. In 1986, Marquart et al. described the case of a 44-year-old HIV-seronegative bisexual man who developed a slowly progressing KS nodule on the glans penis. Garc ıa-Muret et al. reported the case of a 42-year-old white bisexual HIV-seronegative man with disseminated KS limited to the skin and gastrointestinal tract. The CD4/CD8 ratio was normal, and the KS remained indolent over a 30-month follow-up period. Kua et al. reported the case of 53-year-old man who had sex with men and who had KS of the buccal mucosa. The patient was HIV-seronegative with no other cause of immunodeficiency identified. Six HIV-seronegative MSM patients were described by Friedman-Kien et al. in 1990. The mean age of the group was 45 years (range 32–62). Three of the patients had KS lesions limited to the legs only, with two patients developing a single KS lesion on the penis. Lanternier et al. published the largest case series thus far. The series, covering a 12-year period, consisted of 28 HIV-seronegative MSM patients with histologically proven KS. The mean age at diagnosis in this cohort was 55 years (range 35–83). Serological tests for KSHV (latent immunofluorescence assay) were positive in 88% of patients, indicating previous exposure to KSHV. Eighty-nine per cent of the patients in that study had at least one lesion located on the lower limbs. Other involved sites included the upper limbs, face, trunk and genitalia. Epidemiological studies have shown that approximately one-quarter of HIV-seronegative MSM have serological evidence of KSHV infection. Risk factors for KSHV infection in HIV-seronegative MSM include the number of years of sexual activity with men, older age, a higher number of partners, a history of sexually transmitted diseases, and having a partner with KS. KS in the HIV-negative MSM population runs an indolent course similar to classic KS; it is usually chronic, persisting over many years, and presenting as nodules or plaques on the lower extremities. KS in the HIV-positive population can present with multifocal skin lesions and frequently displays mucosal involvement. Visceral disease can also occur, affecting about 10% of patients at diagnosis. It runs a more aggressive course, often requiring highly active antiretroviral therapy and/or systemic chemotherapy. Our case series further highlights the development of KS in HIV-seronegative MSM. We believe the increased risk of KS is secondary to the increased prevalence of KSHV within this population cohort. Further study is required to quantify the absolute magnitude of the risk of developing KS in HIV-seronegative MSM.