Perivascular Epithelioid Cell Tumor Pathology and Treatment

Perivascular epithelioid cell tumours (PEComas) constitute a rare family of mesenchymal neoplasms defined by distinctive epithelioid and myomelanocytic differentiation. Histologically, they range from benign angiomyolipomas to malignant variants showing high mitotic activity, necrosis and vascular invasion. Immunohistochemical profiles characteristically show co-expression of melanocytic markers (HMB-45, Melan-A) and smooth muscle markers (smooth muscle actin, desmin). At the molecular level, loss of function of the TSC1/TSC2 complex leads to aberrant activation of the mTOR pathway, while a subset harbours TFE3 gene rearrangements with distinct clinical features. Surgical resection remains the mainstay for localised PEComas, with complete excision offering the best chance of cure. In metastatic or unresectable disease, mTOR inhibitors such as sirolimus and everolimus have demonstrated significant responses, guiding neoadjuvant, adjuvant and palliative strategies. Prognostic models incorporating tumour size, epithelioid component, mitotic rate and margin status are under validation to inform risk-adapted follow-up. Advances in molecular characterisation now enable more precise diagnosis, risk stratification and targeted therapy, underscoring the global importance of multidisciplinary networks in optimising outcomes for this heterogeneous group of tumours.

Research from Nature Portfolio

A longitudinal analysis of renal epithelioid angiomyolipoma evaluated 52 patients across multiple centres over four years, emphasising the often silent clinical presentation and reliance on postoperative pathology for definitive diagnosis. Immunohistochemical confirmation with HMB-45 positivity proved essential in differentiating epithelioid angiomyolipoma from renal cell carcinoma. Surgical management yielded favourable short-term outcomes, but long-term prognosis correlated negatively with larger tumour size, higher epithelioid cellularity, necrosis and vascular invasion. The study advocates integrated approaches—combining surgery, chemotherapy and targeted therapy—and rigorous follow-up for high-risk lesions, thereby refining clinical guidelines for this aggressive subset of PEComas.

Perivascular Epithelioid Cell Tumor Pathology and Treatment publication trend

The graph below shows the total number of articles in perivascular epithelioid cell tumor pathology and treatment across all publications each year (not limited to Nature Index journals).

Technical terms

Perivascular epithelioid cell tumour (PEComa): A group of rare mesenchymal neoplasms characterised by co-expression of melanocytic and smooth muscle markers.

mTOR pathway: A central signalling cascade regulated by TSC1/TSC2 that controls cell growth and metabolism; its dysregulation drives PEComa proliferation.

Epithelioid angiomyolipoma (EAML): A malignant variant of angiomyolipoma with predominant epithelioid cells, high recurrence risk and potential for metastasis.

TFE3 rearrangement: A genetic alteration involving the TFE3 gene locus that defines a subset of PEComas with distinct clinical and therapeutic implications.

References

1. PEC‐PRO: A new prognostic score from a series of 87 patients with localized perivascular epithelioid cell neoplasms (PEComas) treated with curative intent. Cancer (2024).
2. “Malignant” Perivascular Epithelioid Cell Neoplasm: Risk Stratification and Treatment Strategies. Sarcoma (2012).
3. Successful treatment with the mTOR inhibitor everolimus in a patient with Perivascular epithelioid cell tumor. World Journal of Surgical Oncology (2012).
4. A Four-Year Follow-up Study of Renal Epithelioid Angiomyolipoma: A Multi-Center Experience and Literature Review. Scientific Reports (2015).
5. Neoadjuvant sirolimus for a large hepatic perivascular epithelioid cell tumor (PEComa). World Journal of Surgical Oncology (2014).