Isolated long-standing painless swelling of the hand: A hidden schwannoma unveiled by histopathology

A 20-year-old female presented with a slowly progressive nodular swelling in the 3 rd finger webspace of the left hand for the past 9 years, with occasional mild dragging sensation on movement of the wrist.She had no systemic symptoms or similar family history.On examination, an ovoid swelling, approximately 3 cm in diameter, freely mobile, non-tender, non-pulsating, and firm in consistency was present over the left dorsum of the hand [Figure 1a].ere was no associated sensory loss or Tinel's sign.Ultrasonography showed a hypoechoic soft-tissue mass without any connection to the underlying joint.Differential diagnosis of ganglion cyst, lipoma, neurofibroma, neuroma, xanthoma, and tendon-related tumors was considered.Excision showed a whitish, shiny, lobulated firm mass [Figure 1b].Histopathology showed a well-encapsulated tumor with spindle-shaped cells exhibiting hypercellular and hypocellular areas [Figure 2a], Verocay bodies [Figure 2b], vascular hyalinization, and clear cells [Figure 2c].A final diagnosis of sporadic peripheral cutaneous schwannoma was made.ese rare benign nerve sheath tumors derived from Schwann cells often affect the extremities and trunk and may be associated with neurofibromatosis-2, schwannomatosis, and Carney complex. [1,2]Isolated cutaneous schwannoma diagnosis is clinically challenging, and www.cosmoderma.org