A Rare Atypical Case of Asymptomatic and Spontaneous Intraneural Hematoma of Sural Nerve: A Case Report and Literature Review.

Intraneural hematoma is a rare disease that results in an impaired nerve function because of bleeding around the peripheral nerve, with only 20 cases reported. Trauma, neoplasm, and bleeding disorders are known factors for intraneural hematoma. However, here we report atypical features of asymptomatic and spontaneous intraneural hematoma which are difficult to diagnose. A 60-year-old woman visited our clinic with the complaint of a palpable mass on the right calf. She reported no medical history or trauma to the right calf and laboratory findings showed normal coagulopathy. Ultrasonography was performed, which indicated hematoma near saphenous vein and sural nerve or neurogenic tumor. We performed surgical exploration and intraneural hematoma was confirmed on sural nerve. Meticulous paraneuriotomy and evacuation was performed without nerve injury. Histological examination revealed intraneural hematoma with a vascular wall. No neurologic symptoms were observed. In literature review, we acknowledge that understanding anatomy of nerve, using ultrasonography as a diagnostic tool and surgical decompression is key for intraneural hematoma. Our case report may help establish the implications of diagnosis and treatment. Also, we suggested surgical treatment is necessary even in cases that do not present symptoms because neurological symptoms and associated symptoms may occur later.