PEComas: the past, the present and the future.
The perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumors called PEComas. PEC expresses myogenic and melanocytic markers, such as HMB45 and actin. Recently, recurrent chromosomal alterations have been demonstrated in PEC. At present, PEComa is a widely accepted entity. In the past 10 years, the use of this term has allowed to report and describe numerous cases permitting to start highlighting the biology of this group of lesions. PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease due to losses of TSC1 (9q34) or TSC2 (16p13.3) genes which seem to have a role in the regulation of the Rheb/mTOR/p70S6K pathway. There are some open questions about PEComas regarding its histogenesis, the definition of epithelioid angiomyolipoma and the identification of the histological criteria of malignancy. An innovative therapeutic trial using rapamycin is under way for tumors occurring in TSC such as renal angiomyolipoma and lymphangioleiomyomatosis. Its success could provide the rationale for the use of the same drug in other lesions composed of PECs, especially in the malignant ones.
Martignoni
Guido
G
Department of Pathology, Università di Verona, Verona, Italy.
Pea
Maurizio
M
Reghellin
Daniela
D
Zamboni
Giuseppe
G
Bonetti
Franco
F
D018207:Angiomyolipoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D002869:Chromosome Aberrations; D015622:Epithelioid Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism; D014402:Tuberous Sclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; C000624650:TSC1 protein, human; C000624653:TSC2 protein, human; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins