Point Tenderness for 35 Years: A Rare Presentation of a Glomus Tumor in the Proximal Upper Extremity.

ABSTRACT

Glomus tumors are rare benign neoplasms that are commonly found on the fingers and distal extremities. Clinically, they are often associated with a symptom triad of moderate pain, cold sensitivity, and point tenderness. These tumors are often not considered during a clinical workup due to their rarity and can be misdiagnosed due to their diverse clinical presentations. Glomus tumors are made up of mesenchymal cells derived from glomus bodies, which are specialized arteriovenous (AV) anastomoses primarily responsible for thermoregulation. Microscopically, they present as intricate nests of endothelial cells surrounding glomus bodies, which can clinically manifest as point tenderness. Glomus tumors are usually benign and are commonly found in locations with a high concentration of glomus bodies such as the fingers. Extradigital tumors are very rare and usually not considered in primary diagnosis. This can lead to patients experiencing years and, in this case, decades of unexplained pain. The diagnostic workup for glomus tumors should include an initial Doppler ultrasound and a definitive diagnosis via immunohistochemistry (IHC). They can be completely cured with surgical excision. Although most glomus tumors are benign and easily treatable, they are often not considered in differential diagnoses when assessing for point tenderness.  This case illustrates an atypical presentation of a glomus tumor that caused 35 years of chronic pain and was incidentally misdiagnosed on imaging, leading to treatment delay by an additional eight months. This exemplifies the necessity of including glomus tumors within the differential diagnosis and diagnostic workup for point tenderness and soft tissue masses of the upper extremity.