Glomus tumor: A rare differential diagnosis for subungual lesions

Glomus tumors are rare, benign vascular hamartomas of the glomus apparatus with unknown etiology. They can arise from anywhere in the body. However, up to 90% of them are located in the subungual region of the fingers, as in the case of our patient. These tumors typically present with the classic triad of pain, cold sensitivity, and point tenderness. Characteristic US and MRI findings aid the clinical diagnosis; nevertheless, a histopathologic examination is confirmatory. There is a well-documented mean delay in diagnosis of around 7 years, due to the rarity, benignity, small size, and lack of proper knowledge about the condition. However, we reported a case with a delay in diagnosis that reached 40 years, which is much longer than what is documented in the literature. A high index of suspicion is required for early diagnosis and management of glomus tumors to relieve the patient's long-term suffering and prevent possible secondary nail deformities. The curative treatment of glomus tumor is complete surgical excision, which is crucial to prevent recurrence and relieve the patient's symptoms.