PEComa

PEComas are a family of neoplasms with perivascular epithelioid cell (PEC) differentiation, and are defined by the WHO as "mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells (PECs)."

The best known member of the PEComa family is the angiomyolipoma. Other members of the family include clear cell "sugar" tumor of the lung; lymphangioleiomyomatosis; clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres; and unusual clear tumors of the pancreas, rectum, abdominal serosa, uterus, vulva, thigh, and heart.

The uterus is the most common site of involvement, accounting for about half of the documented cases in the literature, but PEComas can occur anywhere. While more common in women, they can also occur in men.

References

• Pathology and Genetics of Tumours of Soft Tissue and Bone. Fletcher CDM, Unni KK, Mertens F (eds). IARCPress Lyon, 2002.
• Prasad SR, Sahani DV, Mino-Kenudson M, Narra VR, Humphrey PA, Menias CO, Chintapalli KN. Neoplasms of the perivascular epithelioid cell involving the abdomen and the pelvis: cross-sectional imaging findings. J Comput Assist Tomogr. 2007 Sep-Oct;31(5):688-96.