Symplastic glomangioma: information review and addition of a new case.

Glomus tumors are neoplasms differentiating toward specialized cells found in the glomus body, a structure involved in thermoregulation. Although the vast majority is benign, the occurrence of malignant glomus tumors is well recognized. Criteria for prediction of malignant potential include a deep location, large size, infiltration, necrosis, and nuclear atypia. Symplastic glomus tumors are benign neoplasms showing striking nuclear pleomorphism in the absence of other malignant criteria. Recognition of this rare morphologic aberration would prevent an inadvertent diagnosis of malignancy.