Sclerosing variant of PEComa: report of a case and review of the literature

R. Santi¹, A. Franchi¹, D. Villari², M. Paglierani¹, M. Pepi¹, D. Danielli¹, G. Nicita² and G. Nesi¹

Divisions of ¹Pathological Anatomy and ²Urology, University of Florence, Florence, Italy.

Offprint requests to: Raffaella Santi, M.D., Division of Pathological Anatomy, Department of Critical Care Medicine and Surgery, University of Florence, Viale G.B. Morgagni 85, 50134 Florence, Italy. e-mail: raffaella.santi@yahoo.it


Summary. Tumours of perivascular epithelioid cells (PEComas) are a heterogeneous group of uncommon mesenchymal neoplasms which exhibit a peculiar immunohistochemical co-expression of muscle and melanocytic markers. PEComas occur at various visceral and soft tissue sites, generally with a benign clinical course. Nevertheless, there has been evidence of cases having an unfavourable outcome, thus prompting investigation of pathological criteria for malignancy.
A sclerosing variant of PEComa, more frequently encountered in the retroperitoneum of middle-aged women, has been reported. Prognosis has generally been regarded as favourable and complete surgical excision appears to be adequate treatment. To the best of our knowledge, only two cases of sclerosing PEComa displayed high-grade malignant morphology and were associated with adverse outcome.
An additional case of retroperitoneal sclerosing PEComa with a two-year follow-up and indolent behaviour is herein described. Light and electron microscopy were performed, along with immunohistochemical analysis.
Further studies are needed to clarify the histogenesis and to predict the biological behaviour of this uncommon entity. Histol Histopathol 27, 1175-1181 (2012)

Key words: Sclerosing PEComa, PEComa, Retro-peritoneal tumours

DOI: 10.14670/HH-27.1175