SURGICAL MANAGEMENT OF FOREARM EPITHELIOID HEMANGIOENDOTHELIOMA WITH INTEROSSEOUS MEMBRANE INVASION: A CASE REPORT

Abstract

Introduction: Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor of endothelial origin characterized by an intermediate biological behavior between benign hemangioma and aggressive angiosarcoma. It most commonly involves the liver, lungs, and bones, while primary localization in peripheral soft tissues is uncommon. Forearm involvement is particularly rare and represents a diagnostic and therapeutic challenge because of the complex anatomical environment. This case report was prepared in line with the SCARE 2025 guidelines. Case Presentation: We report the case of a 49-year-old woman presenting with a progressively enlarging mass of the left forearm evolving over four years. Clinical examination revealed a firm, painful mass fixed to superficial and deep planes without neurovascular deficit. Imaging studies demonstrated a large hypervascular soft tissue tumor measuring 120 × 37 × 62 mm, initially suggestive of a sarcomatous lesion. Histopathological and immunohistochemical analysis of a biopsy specimen confirmed the diagnosis of epithelioid hemangioendothelioma. The patient underwent wide surgical excision using a combined anterior and posterior approach. Intraoperative findings revealed tumor extension through the interosseous membrane, necessitating segmental resection of approximately 4 cm of the ulna to achieve oncological clearance. Forearm stability was maintained using an acrylic cement spacer reinforced with a transfixing metallic pin. Postoperative recovery was uneventful, with satisfactory functional outcomes and preserved limb function. Clinical discussion: EHE of the forearm is exceptionally rare. Surgical management is particularly challenging due to the dense concentration of neurovascular and musculoskeletal structures. Complete surgical excision remains the cornerstone of treatment, although obtaining wide margins may be difficult in functionally critical regions. Close and prolonged follow-up is required because of the risk of local recurrence and distant metastasis. Conclusion: Epithelioid hemangioendothelioma of the forearm represents a rare entity requiring multidisciplinary management and meticulous surgical planning. This case highlights the importance of adequate oncological resection while preserving limb function whenever possible.