Cabibi D, Giannone AG, Guarnotta C, Schillaci O, Franco V. D2-40 negative pyogenic granuloma-like Kaposi's sarcoma: Diagnostic features and histogenetic hypothesis of an uncommon skin tumor in HIV-negative patients.
Pathol Res Pract 2015;
211:528-32. [PMID:
25939289 DOI:
10.1016/j.prp.2015.03.006]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 03/09/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
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.
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