Polypoid Lesion on the Palm: Answer

Abstract

ANSWERSolitary palmar pyogenic granuloma-like Kaposi sarcoma (PGLKS). DISCUSSIONKaposi sarcoma (KS) is a vascular neoplasm of lowgrade malignant potential that is related to human herpesvirus (HHV)-8 infection. 1,2 Four clinical subtypes of KS are described: African-endemic, iatrogenic, autoimmune deficiency syndrome-related, and classic. 1,2 Classic KS is often seen in older men of Mediterranean or Jewish descent. In addition to the above clinical groups, 3 histopathologic patterns are most commonly reported: patch, plaque, and nodular. 1,2 Other rarely described variants of KS include PGLKS, hyperkeratotic, lymphedematous, infiltrative, florid, telangiectatic, ecchymotic, keloidal and micronodular subtypes. Certain variants, such as anaplastic KS and lymphangiomalike KS, may have prognostic relevance. 1,2 We present a case of solitary palmar pyogenic granuloma PGLKS. This is a rare clinical-histopathologic variant of KS, with less than 30 cases of PGLKS reported in the literature to date. [3][4][5] Similar to other KS variants, PGLKS is mostly commonly described on the lower limbs, including the foot. [3][4][5] Men are predominantly affected, with male-to-female ratio of 7.25:1. In previous reports, age range is wide (25-81 years), with a mean of 60 years. [3][4][5] Most PGLKS patients are HIV-negative. In the PGLKS subtype, it is postulated that superficially located nodular KS lesions may become protuberant and thereby elicit the development of a peripheral epidermal collarette and PG-like architecture. In the majority of described cases of PGLKS, HHV-8 infection has been demonstrated by immunohistochemical or molecular testing. [3][4][5] Traumatized lesions may undergo ulceration and become inflamed, with potential misdiagnosis as true PG. In addition, true PGs may harbor kaposiform areas, compounding histopathologic interpretation.