From a molecular genetic perspective, the recurrent chromosomal alterations in both renal and extrarenal tumors further support the concept of PEComa
as a distinctive tumor entity, regardless of anatomic location.
The World Health Organization (WHO) defines PEComa
as a "mesenchymal tumor that contains perivascular epithelioid cells presenting histological and immunohistochemical differences".
Angiomyolipoma (AML) has undergone a remarkable transformation in recent years, from a rare and rather pedestrian tumor type restricted to kidney, to a biologically fascinating and morphologically heterogenous entity which can occur in a wide variety of sites and which has been given the collective name of PEComa
4) The smooth muscle component is derived from the perivascular epithelioid cell (PEC), and hence, AML is one of a number of tumors classified under the general term PEComa
, a group that includes clear cell tumor and lymphangioleiomyomatosis.
of the bladder treated with primary excision and adjuvant interferon-alpha immunotherapy: a case report.
They appeared to be emanating from the wall of the blood vessels, characteristic of the PEComa
family of tumors (Figure 2).
In this case, a broad differential diagnosis of carcinoma, endometrial stromal tumour and PEComa
were made histopathologically.
IHC positivity is 100% in PEComa
cases for atleast one melanocytic marker, and 100 % positivity for smooth muscle actin in EL cases.
Thereafter, neoplasms with an epithelioid cytomorphology and coexpression of smooth muscle and melanocytic immunomarkers have been increasingly reported under the designation of PEComa
in a wide variety of anatomic locations.
3] Renal AML, a PEComa
, is the most common mesenchymal neoplasm found in 0.