summary Glomus Tumors are rare benign tumors of the glomus body, often occurring in the subungual region. The condition is typically seen in patients between the ages of 20 and 40 who present with a painful subungal mass with bluish discoloration. Diagnosis is made with a biopsy showing a well-defined lesion lacking cellular atypia or mitotic activity with the presence of small round cells with dark nuclei. Treatment is usually marginal excision. Epidemiology Demographics occurs in patients 20 to 40 years of age Anatomic ocation 75% occur in hand 50% are subungual 50% have erosions of distal phalanx (primary involvement of bone being very rare) less common locations: palm, wrist, forearm, foot Etiology Forms may involve either the soft tissue and/or bone Frequently associated with a delay in diagnosis Anatomy Glomus body the glomus body is a perivascular temperature regulating structure frequently located at the tip of a digit or beneath the nail Presentation Symptoms (classic triad) paroxysmal pain exquisite tenderness to touch cold intolerance Physical exam small bluish nodule often difficult to see, especially in the subungual location nail ridging or discoloration is common Love test pressure to the area with a pinhead elicits exquisite pain 100% sensitive, 78% accurate Hildreth test tourniquet inflation reduces pain/tenderness and abolishes tenderness to the Love test 92% sensitive, 91% specific Imaging Radiographs glomus tumors can produce a pressure erosion of the underlying bone and an associated deformity of the bone cortex MRI helpful to establish diagnosis present as a low T1 signal and high T2 signal Studies Histology well-defined lesion lacking cellular atypia or mitotic activity small round cells with dark nuclei associated small vessels in a hyaline/myxoid stroma can show gland-like or nest structures, separated by stromal elements Treatment Operative marginal excision is curative indications symptoms affecting quality of life outcomes due to the benign nature of this disease, recurrence is uncommon several cases of malignant glomus tumors have been reported in the literature reconstruction of nail bed contour with autologous fat graft indications for large defects after resection Complications Recurrence 20%