Giant angiolipoma in the forearm: an atypical presentation of a benign tumor

Angiolipoma gigante en antebrazo: una presentación atípica de tumor benigno

Abstract

Abstract

Introduction: Angiolipoma is a benign soft tissue neoplasm, considered a histological variant of conventional lipoma. It is characterized by the presence of mature adipocytes combined with abnormal vascular proliferation, giving it a heterogeneous appearance both macroscopically and histologically. The purpose of this study is to describe a clinical case of a giant angiolipoma of the forearm, an unusual location for this type of benign soft tissue neoplasm. The objective was to detail the diagnostic, surgical, and histopathological approach, as well as to review the relevant literature to contextualize its clinical presentation and management.

Clinical case: The case involved a 52-year-old female patient with a painless mass in the right forearm evolving for over 10 years, associated with hypoesthesia in the third, fourth, and fifth fingers. Magnetic resonance imaging revealed a hypervascular mass consistent with an atypical lipoma; biopsies ruled out malignancy, suggesting angiolipoma. Surgical resection was performed via a "Z"-shaped ulnar approach, extending from the elbow to the wrist, with exposure of the superficial flexor muscle, identification and preservation of the median nerve, and complete tumor removal. Anatomopathological analysis showed a mass weighing 148 grams and measuring 13 × 6.5 × 4.1 cm, containing adipose, muscular, and vascular tissue, confirming the diagnosis of angiolipoma. Histologically, mature adipocytes, irregular vascular proliferation, and fibrinous microthrombi were observed—a characteristic finding of this entity. At the two-week postoperative follow-up, the patient presented mild weakness in wrist flexion (4/5). At seven months, complete functional recovery and absence of recurrence were documented.

Conclusions: In this case, complete surgical resection was curative, with an excellent functional prognosis. The careful surgical approach allowed for safe removal, preserving neurovascular structures. This case highlights the value of comprehensive evaluation and prolonged follow-up in atypical lesions with potential functional compromise.

Keywords: Angiolipoma, forearm, soft tissue neoplasms.