Where on the skin are glomus tumors most likely to be found?

Glomus bodies are cellular shunts made of modified smooth muscle cells derived from Susquet-Hoyer canals. They function to shunt blood from the arterioles to venules from cold body surfaces. They are primarily found on hands and feet. They are distinct from glomus cells that are chemosensors found in the carotid body that monitor oxygen tension in the blood.

Non cancerous tumors arising from these bodies are called glomus tumors. There are two types of glomus tumors, solitary and multiple. The solitary types tend to have paroxysmal pain which can be extreme. Multiple glomus tumors can be a autosomal dominant trait with incomplete penetrance and are less likely to be painful. Both have a predominance on the distal extremities, especially subungual skin.

Two physical examination tests are helpful in diagnosing glomus tumors: Hildreth's sign is positive when the pain disappears following application of a tourniquet on the limb proximal to the painful tumor. A positive Love's test elicits pain by applying direct pressure to a precise area with the tip of a pencil.