title: PEComas of the kidney and of the genitourinary tract.
abstract: PEComas are mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells that are characterized by the coexpression of muscle and melanogenetic markers. This group of lesions includes angiomyolipoma, clear cell "sugar" tumor of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, and rare clear cell tumors of other anatomical sites. In the genitourinary tract, PEComas have been described in the kidney, bladder, prostate, testis, and urethra. Although most PEComas behave as benign tumors, some are potentially malignant, and criteria for malignancy have been suggested for both and renal and extrarenal lesions. Recently, the expression of cathepsin K has been demonstrated in a large number of PEComas and has been proposed as a relatively specific marker to distinguish these proliferations from the majority of human cancers. In addition, a distinctive subset of PEComas harboring TFE3 gene fusions has been reported, giving rise to a possible relationship between them and MiTF/TFE family translocation renal cell carcinomas. The genetic alterations of tuberous sclerosis complex that promote activation of the mTOR pathway have been identified in PEComas. Therapy with mTORC1 inhibitors has been shown to be effective in some cases.
authors: Department of Pathology and Diagnostics, University of Verona, P.Le L.A. Scuro n. 10, Verona 37134, Italy; Department of Pathology, Pederzoli Hospital, Peschiera, Verona, Italy. Electronic address: guido.martignoni@univr.it.
authors: Guido
authors: G
authors: Martignoni
authors: Department of Pathology, Orlandi Hospital, Bussolengo, Verona, Italy.
authors: Maurizio
authors: M
authors: Pea
authors: Department of Pathology and Diagnostics, University of Verona, P.Le L.A. Scuro n. 10, Verona 37134, Italy.
authors: Claudia
authors: C
authors: Zampini
authors: Department of Pathology and Diagnostics, University of Verona, P.Le L.A. Scuro n. 10, Verona 37134, Italy.
authors: Matteo
authors: M
authors: Brunelli
authors: Department of Pathology, Pederzoli Hospital, Peschiera, Verona, Italy.
authors: Diego
authors: D
authors: Segala
authors: Department of Pathology and Diagnostics, University of Verona, P.Le L.A. Scuro n. 10, Verona 37134, Italy; Department of Pathology, Sacro Cuore Hospital, Negrar, Verona, Italy.
authors: Giuseppe
authors: G
authors: Zamboni
authors: Department of Pathology and Diagnostics, University of Verona, P.Le L.A. Scuro n. 10, Verona 37134, Italy.
authors: Franco
authors: F
authors: Bonetti
mesh_terms: D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D054973:Perivascular Epithelioid Cell Neoplasms / Q000473:pathology*; D014565:Urogenital Neoplasms / Q000473:pathology*
keywords: Cathepsin-k; HMB45; Pecoma; mTOR