Congenital infiltrating lipomatosis of the face: report of cases and review of the literature.

Three cases of infiltrating congenital lipomatosis of the face are presented. These lesions shared the following morphologic criteria: 1) nonencapsulated congenital fatty tumor; 2) infiltration of adjacent muscle and soft tissue; 3) absence of lipoblast and malignant characteristics; 4) presence of fibrous elements with numerous nerve bundles and vessels; and 5) hypertrophy of subjacent bone. Although these tumors are benign, all three recurred after surgical excision. Extensive specimen sampling is advisable to exclude infiltrating lipoma, diffuse angiomatosis, infiltrating angiolipoma, and well-differentiated liposarcoma. Relationship with lipoblastomatosis and histogenesis of infiltrating congenital lipomatosis of the face are discussed.