Rare multiple schwannomas of the left upper extremity: A case report

Schwannomas are rare benign neoplasms originating from Schwann cells of peripheral nerve sheaths. The current study presents a distinctive case involving multiple schwannomas along the peripheral nerves of the left upper extremity. The patient exhibited multiple gradually enlarging subcutaneous masses distributed along the nerves of the left upper limb, without pain, neurological deficits or a positive Tinel's sign upon physical examination. Preoperative diagnostic imaging, including high-resolution ultrasonography and magnetic resonance imaging, revealed well-circumscribed, homogeneous soft-tissue masses with characteristic features. Despite these findings, imaging modalities demonstrated limited specificity in conclusively differentiating the upper extremity tumors from other soft-tissue neoplasms. Surgical exploration conducted under general anesthesia identified three encapsulated masses with focal capsular discontinuities, adherent to surrounding skeletal muscle and the median nerve. The masses measured 6×5×3, 5×4×3.5 and 5×3.5×3 cm from proximal to distal, respectively. Complete surgical excision was performed with meticulous preservation of adjacent neurovascular structures. Histopathological analysis confirmed the diagnosis of schwannomas. This report also provides an extensive review of the literature addressing the etiology, clinical presentation, diagnostic techniques and treatment strategies for peripheral nerve schwannomas, contributing to a deeper understanding of this rare neurogenic tumor and aiding in its effective clinical management.