Multifocal Pancreatic and Liver PEComas Mimic Metastatic Tumors: Case Report and Literature Review

Background: Perivascular epithelioid cell tumor (PEComa) is a mesenchyme tumor derived from soft tissues and organs. Its morphology includes several types such as angiomyolipoma, lymphangiomyomatosis and pulmonary clear-cell “sugar” tumor with similar immunophenotype. Multifocal PEComas are rare lesions, which would confuse imaging examination and clinical management. We reported a case of multifocal angiomyolipomas in the pancreas and liver in a young patient. And we reviewed the literature to explore the clinicopathological characteristics and possible pathogenesis of multifocal PEComas.Case presentation: A 28-year-old woman presented with a lesion in the head of the pancreas and liver 5/6 segment respectively, initially suspected of a pancreatic tumor with liver metastasis. To explore the nature of the lesion, a liver mass resection and a pancreatic mass biopsy were performed at the first operation. After the postoperative pathology was confirmed as an epithelioid angiomyolipoma, the patient underwent a pancreatic segmental resection. After the operation, the patient did not receive any adjuvant treatment and was followed up for 25 months without tumor recurrence or metastasis.Conclusion: Multifocal PEComas present a chronic clinical course and have a good prognosis. Surgical resection is the main treatment. In the diagnosis, in addition to metastatic tumors, multifocal lesions also need to be differentiated with multifocal PEComa; in the treatment, radical treatment should not be performed for this type of disease; in the long-term monitoring of the disease, it is necessary to consider the possibility of a second or a greater number of PEComa lesions even many years later.

A Case Report of Multifocal PEComa Affecting the Pancreas and Liver and a Literature Review

Background: Perivascular epithelioid cell tumor (PEComa) is a rare tumor derived from soft tissues and organs. Its morphology includes several types such as angiomyolipoma, lymphangiomyomatosis and pulmonary clear-cell “sugar” tumor with similar immunophenotype. Multifocal PEComa is a rarer lesion, which would cause confusion in imaging examination and clinical management. We reported a case of multifocal angiomyolipoma in pancreas and liver. At the same time, we reviewed the literature to explore the clinicopathological characteristics and possible pathogenesis of multifocal PEComa.Case presentation: A 28-year-old woman presented with a lesion in the head of the pancreas and liver 5/6 segment respectively, initially suspected of pancreatic tumor with liver metastasis. In the liver mass resection and pancreatic mass biopsy, it was found that the two lesions had similar pathological morphology. The tumor cells were mainly epithelioid and spindle cells arranged in nests pattern and partially radially distributed around blood vessels. The tumors had no malignant manifestations in morphology. Immunohistochemical assay showed that the tumor cells expressed melanocytic and smooth muscle markers. A diagnosis of pancreatic and liver angiomyolipoma was rendered.Conclusion: Based on the case we reported here and the other 12 cases we reviewed for the study, multifocal PEComa with no indications of malignancy based on morphology is biologically benign and has a good prognosis. The lesion may be caused by the blood dissemination of tumor cells rather than metastasis. Radical treatment should not be used in clinical management. In addition, follow-up for PEComa would be long-term, because a second PEComa lesion may appear many years later for the “benign” dissemination of tumor cells.

An Inguinal Perivascular Epithelioid Cell Tumor Metastatic to the Orbit

Malignant PEComas are rare mesenchymal neoplasms. These tumors harbor distinct myomelanocytic phenotype. The PEComa family of tumors includes lymphangioleiomyomatosis, angiomyolipoma, clear cell sugar tumor of the lung, and myomelanocytic tumor of the falciparum ligament/ligamentum teres. PEComas have no known normal cell counterpart. Majority of PEComas are benign and occur predominantly in the middle-age women. These tumors are commonly encountered in the uterus. Herein, we report a 20-year-old woman with a left inguinal mass metastatic to orbit, brain, lumbar spine, and skin at presentation. To our knowledge, this is the first case of metastatic PEComa to the orbit. This is the third case of primary PEComa of the inguinal area.