[Subungual glomus tumor. Apropos of a case].

Glomus tumors are rare, though not exceptional. They are considered by some authors as hyperplasia of a normal neuromyo-arterial glomus, by others as a benign tumoral proliferation. Most of them combine the three histological types initially described by Masson. i.e. solid, angiomatous and muco-hyaline. Subungual glomus tumors are more often seen in middle-aged subjects than in children. Although often belatedly diagnosed, they have characteristic symptoms, notably paroxysmal, acute pain provoked by cold or by minimal traumas: the Raynaud's phenomenon is inconstant and localized to the tip of the affected finger. When clinical and standard radiological examinations are normal, arteriography may be useful to confirm the diagnosis and locate the lesion. The main differential diagnoses before arteriography are post-traumatic neuroma and subungual melanoma. Surgical treatment is straightforward, but pain may recur post-operatively; it may be due to incomplete excision, development of a new tumor, presence of other tumors or cicatricial neuroma.