LAUSR

ABSTRACT Introduction: Perivascular epithelioid cell tumor (PEComa) constitutes a family of rare mesenchymal soft-tissue tumors. These tumors pose a significant diagnostic challenge, given their cytomorphology and characteristic co-expression of both melanocytic and myogenic markers. While most PEComas show benign behavior, a subset of PEComas can act malignantly. Historically, cytotoxic chemotherapy used in other soft-tissue sarcomas has shown little benefit. However, a growing understanding of the role of aberrant mTOR pathway activation in these tumors has yielded multiple reports of durable tumor responses and clinical benefit with mTOR inhibitors such as sirolimus, temsirolimus, and everolimus. Areas covered: We describe the histopathology, molecular features and differential diagnosis of the PEComa family and review available data on treatment strategies for localized and advanced PEComa. A literature search was performed using PubMed, American Society of Clinical Oncology, and ClinicalTrials.gov websites. Expert opinion: mTOR inhibitors are emerging as the standard approach to the management of advanced PEComa. Results of the clinical trial for advanced PEComa with ABI-009, a nanoparticle albumin-bound mTOR inhibitor, will provide the first prospective data of mTOR inhibition in PEComa, and may establish a relationship between genotype and outcome.