Retroperitoneal perivascular epithelioid cell tumours: A case report and review of literature

Abstract

BACKGROUNDThe perivascular epithelioid cell tumour (PEComa) family of tumours mainly includes renal and hepatic angiomyolipomas, pulmonary lymphangioleiomyomatosis and clear cell “sugar” tumour of the lung. Several uncommon tumours with similar morphological and immunophenotypical characteristics arising at a variety of sites (abdominal cavity, digestive tract, retroperitoneum, skin, soft tissue and bones) are also included in the PEComa family and are referred to as PEComas not otherwise specified.CASE SUMMARYWe present a 37-year-old female patient who underwent resection of an 8.5 cm × 8 cm × 4 cm retroperitoneal tumour, which eventually was diagnosed as PEComa of uncertain biological behaviour. Three years after the operation, the patient remains without any evidence of recurrence. A search was performed in the Medline and EMBASE databases for articles published between 1996 and 2018, and we identified 31 articles related to retroperitoneal and perinephric PEComas. We focused on sex, age, maximum dimension, histological and immunohistochemical characteristics of the tumour, follow-up and long-term outcome. Thirty-four retroperitoneal (including the present one) and ten perinephric PEComas were identified, carrying a malignant potential rate of 44% and 60%, respectively. Nearly half of the potentially malignant PEComas presented with or developed metastases during the course of the disease.CONCLUSIONRetroperitoneal PEComas are not as indolent as they are supposed to be. Radical surgical resection constitutes the treatment of choice for localized disease, while mammalian target of the rapamycin (mTOR) inhibitors constitute the most promising therapy for disseminated disease. The role of mTOR inhibitors as adjuvant or neoadjuvant therapies needs to be evaluated in the future.

Retrospective analysis of hepatic perivascular epithelioid cell tumour (PEComa) in a single centre for clinical diagnosis and treatment clinical diagnosis and treatment of hepatic PEComa

“…[ 21 ] In addition, PEComa may stem from myoblasts or smooth muscle cells that have mutated at the molecular level, and the pericytes are likely to be the ancestors of PEComa. [ 27 ] The volume of a hepatic PEComa can change over a wide range. Maebayashi et al [ 3 ] examined 74 cases and reported a maximum size of these tumours of 25 cm, and the minimum size was 1.2 cm in our study.…”

Surprising genetic and pathological findings in a patient with giant bilateral periadrenal tumours: PEComas and mutations of PTCH1 in Gorlin-Goltz syndrome

“…Angiomyolipomas are among the most common form of PEComas, but there are several uncommon forms. Retroperitoneal localisation has recently been established as the third most frequent, but altogether rare PEComa localisation 9…”

Multifocal retroperitoneal and pelvic PEComas mimicking liposarcoma: A case report and review of literature

“…Autosomal dominant mutations of the TSC1 or TSC2 tumor suppressor genes lead to tuberous sclerosis, characterized by a multi-system development of benign tumors (such as subependymal giant cell tumors and cardiac rhabdomyomas), as well as seizures, cognitive delays, and cutaneous findings [9] , [10] , [11] . Some of these were observed in our patient, compatible with a presumptive clinical diagnosis of TSC.…”

“…In the kidney, the main differential is AML, with varying amounts of angiogenic, myogenic, and fatty elements. A fat-rich appearance is most common, though the lesion may often appear with a hyperdense collection obscuring the fatty component due to presence of perirenal or intratumoral hemorrhage [9] . Calcification and necrosis have also been observed, raising the possibility of fat-containing renal cell carcinoma [17] .…”

“…PEComas are characteristically composed of nests or bands of mainly epithelioid and occasionally spindle-shaped cells, seen surrounding blood vessels [7] , [9] , [10] . PECs exhibit clear to granular eosinophil cytoplasm, and round to oval, centrally-located nuclei and inconspicuous nucleoli.…”