Brace yourself: an unusual case of knee pain, an extradigital glomangioma of the knee.

The differential diagnosis for knee pain is extensive. Glomus tumors comprise approximately 1.6% of soft-tissue tumors in the extremities. Classic subungual tumors occur more frequently in women, whereas ectopic locations are more common in men. Unusual locations include the stomach; lungs; trachea; bones; intestines; fallopian tubes; and intraneural, neuromal, and intravenous locations. We present the case of a 50-year-old man with a 12-year history of enlarging right knee mass found to be a glomangioma. This case report discusses the incidence, presentation, imaging characteristics, histology, and management of glomus tumors of the knee.