Glomus tumor
The glomus tumor consists of endothelial-lined vascular spaces surrounded by glomus cells which are small and round
with scanty cytoplasm. On EM the cells show smooth muscle characteristics. The tumors are painful, especially when
subungual. The glomus cell is normally found in dermal thermoregulatory glomus bodies (neuromyoarterial glomus of Masson).