Subcutaneous Angiofibroma of the Ankle: A Rare, Undescribed Clinical Entity.

Soft tissue angiofibroma is a pathology consisting of a benign fibrous vascularized tumor that mimics low-grade sarcoma. Such tumors frequently arise in the extremities, more commonly in the lower extremities, presenting as a slow-growing, painless swelling. Females are more commonly affected than males. We present the case of a 42-year-old male with a slow-growing, painless mass on the extensor aspect of his left foot. Differential diagnoses considered were soft tissue fibrosarcoma, liposarcoma, and sebaceous cysts. Surgical excision of the tumor was done, and upon histopathology, there were multiple lobules with well-circumscribed, alternating areas of collagenous and myxoid tissues. There was a prominent small vascular network with uniformly arranged spindle cells consisting of pale eosinophil-rich cytoplasm and small ovoid nuclei, fine chromatin, and an indistinct nucleolus. There are not many reported cases of this clinical entity, and every new case reported brings light to the pathology and progression of this tumor. Understanding this pathology is necessary since it mimics many other skin and soft tissue tumors.