Sporadic segmental schwannomatosis confined to a single finger: a case report describing preoperative diagnosis with ultrasonography

Schwannomas are common benign peripheral nerve sheath tumors arising from Schwann cells. While they are frequently found in the head, neck, thorax, and retroperitoneum, they are rarely encountered in the hand, particularly within the fingers. We present a rare case of a 43-year-old male with multiple schwannomas confined to a single digit, involving both the radial volar and dorsal digital nerves of the right ring finger. Based on established diagnostic criteria, the condition was diagnosed as sporadic segmental schwannomatosis. Following microsurgical excision, histopathological examination confirmed the diagnosis. The patient recovered without neurological deficits or limitations in the range of motion. Given the rarity of this presentation and the limited literature available, this case highlights the clinical and histopathological features and the diagnostic approach for multiple schwannomas occurring within a single finger.