Hidden in Plain Sight: The Diagnostic Odyssey of Glomus Tumors

Glomus tumors are benign mesenchymal neoplasms arising from specialized neurovascular dermal structures known as glomus bodies, which participate in thermoregulation by modulating cutaneous blood flow. While these tumors are predominantly located in the subungual and periungual regions of the distal extremities, they may arise at extradigital sites, where atypical presentations frequently delay diagnosis. Despite the availability of a well-established clinical triad, these tumors are notoriously difficult to diagnose promptly. We present three surgically confirmed cases of glomus tumor, each representing a distinct clinical presentation: a classic subungual digital tumor, an extradigital forearm tumor, and a recurrent digital tumor. All three cases were characterized by significant diagnostic delay. A comprehensive literature review was conducted using PubMed, with search terms including "glomus tumor", "diagnostic delay", "recurrence", "extradigital glomus tumor", and "satellite lesion". The search included articles published between 1972 and 2026. Relevant case reports, retrospective series, and review articles were reviewed and synthesized in conjunction with the presented cases. The three cases illustrate that diagnostic delay in glomus tumors is a widespread and recurring pattern with significant clinical consequences. Delayed diagnosis deprives patients of timely appropriate preoperative imaging, compromises surgical planning, and may increase the risk through the failure to identify satellite lesions preoperatively. Early application of the bedside diagnostic triad, combined with routine preoperative imaging, is essential to improving outcomes for this frequently overlooked tumor. The three cases presented share several common clinical features. Histopathologic diagnosis was similar in all three cases. The pain and tenderness on physical examination was a prominent clinical feature of all the cases. They all presented a diagnostic challenge as well as a delayed diagnosis. Surgical excision of all three lesions resulted in complete resolution of the symptoms and signs. The significance of the common findings is that even with a recurrent lesion, as well as an extra-digital location, glomus tumors can have various presentations, but the underlying features are recognizable.