Fine needle aspiration diagnosis of lipoblastoma of the parotid region. A case report

BACKGROUND: Lipoblastomas are rare tumors of embryonal fat that occur in infants and children. They are usually located in the extremities and trunk. Two cases in the parotid region have been described. A diagnosis on fine needle aspiration (FNA) specimens has been reported in six cases. CASE: Lipoblastoma of the parotid region occurred in a 6-year-old boy and was diagnosed by FNA. Cytology showed rare lipoblasts and hibernomalike cells in a myxoid background with spindle and stellate mesenchymal cells, mature adipose cells and plexiform capillaries. A 7.0-cm, well-circumscribed mass with lobulated adipose tissue and delicate fibrous bands was resected. Microscopically, it showed a lobulated myxoid stroma, many capillaries, mesenchymal cells, lipoblasts and mature adipose cells. CONCLUSION: Lipoblastoma has to be differentiated from myxoid and lipomatous soft tissue tumors, especially from myxoid liposarcoma, a malignancy that classically affects older individuals and shows pleomorphism, atypical lipoblasts and chromosome-12 translocation. A lipoblastoma diagnosis must be established only after careful consideration of all available clinical, radiologic, cytogenetic and morphologic data.