Extradigital Glomus Tumor of the Ankle Associated With Tibial Neuropathy: A Case Report.

We report the case of a 26-year-old man with a 14-year history of severe, highly localized pain and allodynia in the right medial retromalleolar region. He had undergone multiple previous medical evaluations and had repeatedly been treated for presumed tendinopathy without meaningful improvement. Magnetic resonance imaging (MRI) of the right ankle demonstrated multiple soft-tissue lesions involving superficial and deep tissue planes around the ankle and hindfoot. Electroneuromyography revealed severe focal axonal neuropathy of the right tibial nerve and its plantar branches. Surgical exploration and excision of the symptomatic lesion were performed. Histopathological examination demonstrated tortuous vascular channels surrounded by uniform round cells, with immunohistochemical positivity for smooth muscle actin and type IV collagen and focal positivity for caldesmon, supporting the diagnosis of a glomus tumor of the glomangioma subtype. The patient experienced immediate and complete resolution of pain and remained asymptomatic at six-month follow-up. This case demonstrates an unusual presentation of an extradigital glomus tumor associated with multiple ankle and hindfoot lesions on MRI and severe focal tibial neuropathy. In patients with persistent, highly localized ankle or foot pain and marked allodynia unexplained by conventional musculoskeletal diagnoses, a glomus tumor may warrant consideration.