Superficial acral fibromyxoma (SAF) is a fibromyxoid tumor with a predilection for the hands and feet, which was first described in 2001.
Superficial acral fibromyxoma most often presents as a slow-growing, nodular mass at acral sites.
Previously published series suggest that the toes are more commonly affected than the fingers, with the majority involving the subungual or periungual region; however, the heel, palm, and ankle can also be affected.
Males are affected approximately twice as often as females, with the average age of presentation in the fifth to sixth decade of life.
Most tumors are asymptomatic or only mildly tender with pressure, often leading to a delay in patients seeking medical treatment.
Management of these tumors typically involves complete excision to rule out malignancy and prevent recurrence.
The gross appearance of the tumor is typically a firm, nodular, or lobulated mass with a whitish cut surface that can range from solid to gelatinous.
The tumor usually involves the dermis, often with extension into the subcutaneous tissue.
Occasionally, extension to the fascia or periosteum can cause pressure erosion of the underlying bone.
The histologic appearance of SAF consists of fibroblast-like cells with a storiform or fascicular pattern embedded in a predominantly myxoid, myxocollagenous, or collagenous matrix.
Increased numbers of ectatic blood vessels and mast cells are commonly seen.
Tumor cells typically express CD34, CD99, vimentin, and epithelial membrane antigen and are negative for cytokeratin, muscle, and melanocytic markers.