Reverse adipofascial flap after resection of a malignant perineurioma of the forearm.

Abstract

The authors describe a patient with recurrent perineurioma arising in the subcutaneous tissue of the dorsal forearm and extending along the forearm fascia. Soft tissue perineurioma is a rare, originally benign peripheral nerve sheath neoplasm arising from the perineurium, a protective cell barrier surrounding the individual fascicles in peripheral nerves. Perineurioma has only recently been recognized as an entity distinct from other nerve sheath tumors, such as schwannoma and neurofibroma, with unique morphologic, ultrastructural, and immunoreactive features. The recurrent tumor had converted into malignant perineurioma, defined as increased nuclear pleomorphism and cellularity. The ill-marginate feature extending along the fascia required wide resection, leaving a substantial defect on the distal forearm. Surgical repair of large forearm skin defects is challenging because of limited skin extensibility for flap creation, the prominence of the site in terms of aesthetic outcome, and the risk of damage to extrinsic muscles that control delicate hand movements. The reverse forearm adipofascial flap, which was based on distal perforators of the radial artery, was suitable for the current case to cover the exposed myotendinous junctions of the forearm extensor muscles. This flap did not sacrifice skin, a major vessel, or skeletal muscles, and preserved function at both the donor and the recipient sites. The texture of the graft was similar to that of the surrounding skin. The clinical and histopathologic features of this rare tumor are also described to aid in the differential diagnosis and as a reference for surgeons who treat soft tissue neoplasms and may encounter this type of soft tumor.