Soft tissue tumors: Lipoblastoma

Clinics and pathology Disease Benign uncommon soft-tissue tumor of embryonal fat. Embryonic origin Develops from embryonic remnants of white fat tissue. Epidemiology Primarily occurs in young children (<3 years) prevalently male. Clinics Presents in superficial tissues of arms and legs (deeper in lipoblastomatosis), though mediastinum, retroperitoneum, trunk, head and neck may be affected. Pathology Lobulated tissue composed of immature fat cells separated by fibro-vascular septa and areas with a myxoid matrix. The lobules contain lipoblasts in different stages of differentiation, ranging from primitive, spindle-shaped cells to lipoblasts simulating mature fat cells. Differential diagnosis, particularly in older children or in diffuse lipoblastoma, includes myxoid liposarcoma and atypical lipoma and may be based on distinct cytogenetic abnormalities. Treatment Surgical excision. Prognosis These tumors have an excellent prognosis but local recurrence is possible expecially in diffuse lesions.