D2-40 negative pyogenic granuloma-like Kaposi's sarcoma: Diagnostic features and histogenetic hypothesis of an uncommon skin tumor in HIV-negative patients.

Abstract

Locate full-text(opens in a new window)|View at Publisher| Export | Download | Add to List | More... Pathology Research and Practice Volume 211, Issue 7, July 01, 2015, Pages 528-532 D2-40 negative pyogenic granuloma-like Kaposi's sarcoma: Diagnostic features and histogenetic hypothesis of an uncommon skin tumor in HIV-negative patients (Article) Cabibi, D.a, Giannone, A.G.a , Guarnotta, C.a, Schillaci, O.b, Franco, V.a a Department of Sciences for Promotion of Health and Mother and Child Care, University of Palermo, Palermo, Italy b Servizio di Anatomia Patologica, Dipartimento Oncologico di III livello, La Maddalena Casa di Cura di Alta Specialità, Palermo, Italy View references (20) Abstract Pyogenic granuloma-like Kaposi's sarcoma (PGLKS) is a recently described skin tumor showing features both of pyogenic granuloma (PG) and Kaposi's sarcoma (KS). The differential diagnosis is often challenging. We reviewed a series of 50 PG and 23 Ks located on distal extremities with the aid of an immunohistochemical panel comprising CD34, CD31, FVIII, SMA, D2-40, HHV8. After revision, 6/50 PG lesions previously diagnosed as PG, showed positive immunostaining for LNA1-HHV8 and focal positivity for CD31 and FVIII in the endothelial cells of the proliferating vessels, with some SMA positive pericytes. D2-40, a marker of lymphatic endothelium positive in KS, stained negatively. These lesions were renamed PGLKS. Of note, in our series, PGLKS represented the only form of KS localized in the hand all the patients were HIV-negative, older than PG patients, with a prevalence for male gender. PGLKS and PG need a different management and a follow-up is advisable for PGLKS, as for the other variants of KS. To date, D2-40 negative immunostaining has not yet been reported in PGLKS and should not lead to a misdiagnosis of PG. The morphological similarities with PG and the immunohistochemical findings, showing a defective phenotype of the neoplastic cells, suggest a histogenetic hypothesis in which D2-40 negative PGLKS could represent an early stage of HHV8 infection of a pre-existing PG, whose vessels loose progressively their blood vascular markers but have not still acquired the lymphatic ones