Perivascular epithelioid cell tumours (PEComas)
Perivascular epithelioid cells tumours (PEComas) are a group of related mesenchymal tumours and tumour-like conditions found in many locations. This group includes:
- angiomyolipoma (AML)
- clear cell 'sugar' tumour of the lung
- lymphangioleiomyomatosis (LAM)
clear cell myomelanocytic tumour (CCMMT)
- of the falciform ligament / ligamentum teres
- unusual clear tumours of other organs
- abdominal serosa
- uterus - considered one of the commonest sites of involvement in the female pelvis
PEComas are far more common in females 4.
All PEComas share similar and distinctive cellular morphology – peripheral epitheloid cells – which have no counterpart in normal tissue 4. These tumours appear as sheets and nests of epithelioid or spindle-shaped cells associated with blood vessel walls. They have granular eosinophilic cytoplasms.
PEComas are characterised by immunoreactivity to smooth muscle and melanocytic markers 4.
- smooth muscle: actin, desmin
- melanocytic: HMB-45, melan-A
Treatment and prognosis
PEComas usually behave in a benign fashion although local recurrence and even malignant behaviour are encountered, mimicking malignant sarcomas.
Surgical excision is usually curative.
- 1. Lai HY, Chen CK, Lee YH et-al. Multicentric aggressive angiomyolipomas: a rare form of PEComas. AJR Am J Roentgenol. 2006;186 (3): 837-40. doi:10.2214/AJR.04.1639 - Pubmed citation
- 2. Fadare O, Parkash V, Yilmaz Y et-al. Perivascular epithelioid cell tumor (PEComa) of the uterine cervix associated with intraabdominal "PEComatosis": A clinicopathological study with comparative genomic hybridization analysis. World J Surg Oncol. 2007;2 (1): 35. doi:10.1186/1477-7819-2-35 - Free text at pubmed - Pubmed citation
- 3. Armah HB, Parwani AV. Malignant perivascular epithelioid cell tumor (PEComa) of the uterus with late renal and pulmonary metastases: a case report with review of the literature. Diagn Pathol. 2007;2 (1): 45. doi:10.1186/1746-1596-2-45 - Free text at pubmed - Pubmed citation
- 4. Hornick JL, Fletcher CD. PEComa: what do we know so far?. Histopathology. 48 (1): 75-82. doi:10.1111/j.1365-2559.2005.02316.x - Pubmed