[Rare localization of a glomus tumor in the knee].

The glomus tumor, characterized by the classic trio of tumefaction, acute pain on palpation, and sensitivity to cold, is localized most commonly in the hand and quite rarely in the knee. It occurs most frequently in subjects between the ages of 20 and 40, and its cause is unknown. Masson divided glomus tumors into 4 main types: angiomatous, stromal, nervous, and myxoid, according to the histo-pathological features present. The authors believe that the histological appearance may be affected by the functional phase of the tumor at the moment of surgery: with sphincters closed, meaning very little dilatation of the venous collection areas, or with sphincters open, meaning considerable dilatation of the venous collection areas due to increased hematic flow.