A rare case of myxoid pleomorphic liposarcoma in an infant: A report

INTRODUCTION AND IMPORTANCE: MPL (myxoid pleomorphic liposarcoma) is an uncommon type of liposarcoma that affects mostly children and infants. Its aggressive behavior and tendency to recur warrant complete excision despite the challenges of troublesome locations. CASE PRESENTATION: A 12-month-old infant presented with an insidious onset of noisy breathing and respiratory distress not relieved by supplemental oxygen via face mask. Examination revealed dullness and decreased air entry on the left chest. Computed Tomographic (CT) scan showed a large solid mass occupying the left hemithorax and displacing the mediastinum to the right. Intraoperatively, a large solid mass arising from the left chest wall and attached to the fifth rib was seen. Histopathology of the resected mass showed myxoid pleomorphic liposarcoma which is non-reactive for MDM2 immunostain. CLINICAL DISCUSSION: Unlike other liposarcomas, myxoid pleomorphic liposarcoma occurs in children, commonly in the chest. CT scan is the preferred imaging modality. Treatment is by complete excision where possible. Molecular studies like Fluorescent in-situ Hybridization (FISH) and Immunohistochemistry (IHC) is used for confirmation. It has a high propensity to metastasize and recurrence is expected. Chemotherapy and irradiation following complete resection decrease the disease recurrence. CONCLUSION: Soft tissue malignancy must be considered in the differential diagnosis of a large intrathoracic tumor in an infant. FISH and IHC are essential for confirmation.