Primary Abdominal Wall Angiosarcoma: A Case Report of Diagnostic Challenges, Local Recurrence, and Metastatic Progression.

Angiosarcoma is an uncommon and aggressive vascular malignancy that may present with nonspecific clinical features, often mimicking benign conditions and leading to delayed diagnosis. We present a case of a 74-year-old man who presented with a progressively enlarging lesion of the anterior abdominal wall, initially presumed to be a hematoma. Imaging revealed subcutaneous lesions, and surgical excision was performed. Gross examination demonstrated a fungating gray-tan mass with surrounding areas of hemorrhagic discoloration. Histopathologic evaluation revealed a high-grade, poorly differentiated angiosarcoma involving the dermis and subcutaneous tissue, characterized by markedly atypical endothelial cells forming irregular vascular channels, as well as solid and spindle cell areas with numerous mitotic figures. Following initial resection, the patient developed local recurrence requiring multiple subsequent surgical excisions. Despite multimodal management, including repeated surgeries and radiotherapy, the disease progressed, with the development of metastatic lesions involving musculature and bone. Systemic chemotherapy was initiated upon progression. This case highlights the aggressive clinical course of angiosarcoma, its propensity for local recurrence and distant metastasis, and the diagnostic challenges posed by its variable presentation. Early recognition, histopathologic confirmation, and a multidisciplinary approach are essential for optimal management.