Abdominal Wall Perivascular Epithelioid Cell Tumor Mimicking an Intra-Abdominal Tumor: A Case Report.

Abstract

<h4>Introduction</h4>Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms; those arising from the abdominal wall are exceptionally uncommon. Because imaging findings are nonspecific, an abdominal wall PEComa may be mistaken for an intra-abdominal tumor, leading to diagnostic uncertainty and challenges in surgical planning.<h4>Case presentation</h4>A 25-year-old woman was referred to our hospital after a screening of the upper gastrointestinal series revealed extrinsic compression of the stomach. Cross-sectional imaging demonstrated a well-circumscribed midline mass with early enhancement and calcifications, which was initially suspected to be intra-abdominal in origin. Because the precise anatomical origin of the lesion remained unclear and malignancy could not be excluded, a laparoscopic first-look approach was employed. Intraoperative inspection confirmed that the tumor originated from the subperitoneal abdominal wall, without intraperitoneal involvement. The lesion was resected en bloc with negative margins through a limited incision. The histopathological and immunohistochemical findings were consistent with those of a PEComa with malignant potential. The postoperative course was uneventful, and no recurrence was observed during follow-up.<h4>Conclusions</h4>Abdominal wall PEComa is an extremely rare entity that can closely mimic an intra-abdominal tumor on imaging studies. When the anatomical origin of a midline mass cannot be clearly determined preoperatively, a laparoscopic first-look approach is a useful strategy for clarifying the tumor's origin and guiding safe surgical management. Long-term follow-up is warranted because of the malignant potential of PEComas.