The Tiny Tumor with Disproportionate Pain: Subungual Glomus Tumor of the Thumb Managed with Nail-Sparing Excision: A Case Report.

INTRODUCTION: Glomus tumor is a rare benign vascular neoplasm arising from the glomus body, a specialized thermoregulatory arteriovenous shunt concentrated in the digits. Although small in size, these tumors produce disproportionate pain and significant impairment in quality of life. Delayed diagnosis is common due to non-specific presentation and subtle imaging findings. CASE REPORT: A 21-year-old male presented with severe localized pain over the left thumb for 6 months. The pain was insidious in onset, progressive in nature, and associated with marked cold hypersensitivity. The patient described excruciating pinpoint pain near the nail bed, aggravated while washing hands and during exposure to cold weather. There was no history of trauma, smoking, steroid use, or systemic illness. Clinical examination revealed localized tenderness over the subungual region without visible swelling or deformity. Plain radiographs demonstrated subtle cortical scalloping of the distal phalanx. Magnetic resonance imaging (MRI) revealed a well-defined subungual lesion that was hypointense on T1-weighted images and hyperintense on T2-weighted images, consistent with glomus tumor. The patient underwent complete surgical excision through a nail-sparing paraungual approach. Histopathological examination confirmed the diagnosis of glomus tumor. Postoperatively, the patient experienced dramatic pain relief with restoration of normal thumb function and no evidence of recurrence during follow-up. CONCLUSION: Glomus tumor should be considered in patients presenting with chronic fingertip pain, cold sensitivity, and localized tenderness even in the absence of obvious swelling. MRI plays a crucial role in diagnosis and surgical planning. Complete surgical excision using a nail-preserving approach provides excellent symptomatic relief and functional outcome.