PEComa pulmonar / PEComa of the lung

Resumen Los tumores de células claras "de azúcar" (CCTL) son lesiones benignas muy infrecuentes. Forman parte de un grupo de neoplasias mesenquimales denominadas PEComas que se originan de las células epiteloides perivasculares. Por su rico estroma vascular, suelen tener avidez por los distintos tipos de contrastes utilizados en los estudios de diagnóstico por imágenes, simulando lesiones de estirpe maligna. Presentamos el caso de un paciente de 66 años con hallazgo de un nódulo pulmonar durante la estadificación oncológica por adenocarcinoma de próstata al que se le realizó una segmentectomía pulmonar anatómica. El resultado definitivo de anatomía patológica fue tumor de células epiteloides perivasculares (PEComa pulmonar o tumor de células claras "de azúcar").

Abstract Clear cell ''sugar'' tumor of the lung is a rare benign tumor arising from perivascular epithelioid cells (PECs). They belong to a group of mesenchymal neoplasms called PEComas. Although widely presumed as benign, due to their rich vascular stroma they are usually avid for the different types of contrast agents used in imaging studies, mimicking a malignant lesion. We report the case of a 66-year-old man in whom a solitary pul monary nodule was discovered during oncological staging for an adenocarcinoma of the prostate who underwent an anatomical pulmonary segmentectomy. The final pathology result was a perivascular epithelioid cell tumor (pulmonary PEComa or clear "sugar" cell tumor).

Hepatic perivascular epithelioid cell tumor (PEComa): a case report with a review of literatures

Hepatic perivascular epithelioid cell tumors (PEComas) are very rare. We report a primary hepatic PEComa with a review of the literature. A 56-year-old women presented with a nodular mass detected during the management of chronic renal failure and chronic hepatitis C. Diagnostic imaging studies suggested a nodular hepatocellular carcinoma in segment 5 of the liver. The patient underwent partial hepatectomy. A brown-colored expansile mass measuring 3.2×3.0 cm was relatively demarcated from the surrounding liver parenchyma. The tumor was mainly composed of epithelioid cells that were arranged in a trabecular growth pattern. Adipose tissue and thick-walled blood vessels were minimally identified. A small amount of extramedullary hematopoiesis was observed in the sinusoidal spaces between tumor cells. Tumor cells were diffusely immunoreactive for human melanoma black 45 (HMB45) and Melan A, focally immunoreactive for smooth muscle actin, but not for hepatocyte specific antigen (HSA).

Uncommon of the Uncommon: Malignant Perivascular Epithelioid Cell Tumor of the Lung

A perivascular epithelioid cell (PEC) tumor is a rare mesenchymal tumor characterized by abundant cytoplasmic Periodic acid-Schiff positive glycogen (also called sugar tumor or clear cell tumor of the lung for this characteristic) and is mostly benign. We report a case of a 63-year-old man who presented with an enlarging mass on chest radiograph. After a thorough workup, diagnosis of malignant pulmonary PEC tumor with lung to lung metastases was established. Herein, the difficulties of diagnosis and management we confronted are described.

Retroperitoneal sclerosing PEComa with melanin pigmentation and granulomatous inflammation-A rare association within an uncommon tumor.

PEComa, defined as a perivascular epithelioid cell tumor, displays a wide clinicopathological spectrum. Lately, a sclerosing PEComa has been identified as its distinct variant, but with limited documentation, in view of its rarity. Herein, we describe an uncommon case of a 53-year-old lady, who was referred to us with pain abdomen. Radiological imaging disclosed a well-defined, hypodense retroperitoneal mass. The excised tumor was a round, encapsulated soft tissue mass measuring 7 cm with a tan-brown cut surface. Microscopy showed uniform, epithelioid cells with clear cytoplasm, focal melanin pigmentation and mild nuclear atypia, arranged in sheets and nests around capillary-sized vessels in a dense sclerotic stroma. Additionally, co-existing epithelioid granulomas were noted. On immunohistochemistry (IHC), tumor cells were diffusely positive for HMB45; focally for desmin and smooth muscle actin (SMA), while negative for EMA, CD10, S100-P, Melan A, CD34, AMACR and CK MNF116. This case reinforces sclerosing PEComa as an uncommon, but a distinct clinicopathological entity and exemplifies diagnostic challenge associated with it; necessitating application of IHC markers for its correct identification. Presence of melanin pigment and granulomatous inflammation in the present tumor constitute as novel histopathological findings in a sclerosing PEComa.

A Case of Primary Cutaneous Perivascular Epithelioid Cell Tumor / 대한피부과학회지

Perivascular epithelioid cell tumors (PEComas) are a rare, recently described group of mesenchymal tumors, which is composed of distinctive perivascular epithelioid cells. Primary cutaneous PEComas are composed of focally nested or trabecularly arranged groups of epithelioid cells with clear to eosinophilic cytoplasm and round to oval nuclei with obvious nucleoli. Here, we describe the case of a 27-year-old Korean man who was presented with a solitary, cutaneous nodule on his left popliteal fossa. Physical examination revealed a solitary, 1.2x1.0 cm-sized erythematous protruding nodule on his left popliteal fossa. Immunohistochemical evaluation showed that the epithelioid tumor cells were positive for HMB-45 and desmin. These clinical and histological findings were consistent with a diagnosis of primary cutaneous PEComa.

Perivascular epithelioid cell tumor (PEComa) of the ascending colon: the implication of IFN-alpha2b treatment / 소아과

A 7-year-old boy presented with hematochezia and abdominal pain. A 3.7-cm-sized mass was identified in the ascending colon by abdominal computed tomography and colonoscopy. The patient underwent surgical resection. Pathological examination revealed a low-grade perivascular epithelioid cell tumor (PEComa). PEComa in the colon is very rare. Only a few cases have been reported so far. An effective treatment method for this rare tumor has not been established yet. The patient received adjuvant interferon-alpha immunotherapy for 1 year. He has been tumor-free for 26 months since the initial diagnosis. This report is the first documented case of the use of interferon-alpha for pediatric PEComa of the colon.

A case of perivascular epithelioid cell tumor (PEComa) at the uterus / 대한산부인과학회지

Perivascular epithelioid cell tumors (PEComas) at the uterus are very rare tumors and about 30 cases have been reported as far as we know. As a case was experienced at our hospital, we would like to report it with a brief review of literature.