Abstract
INTRODUCTION AND IMPORTANCE: Lipoblastoma is a rare benign tumor of embryonic adipose cells, at different stages of maturation, which commonly occurs in infancy and early childhood. CASE PRESENTATION: A toddler presented with a painless, gradually enlarging swelling in the left chest wall region over a period of 6 months. Imaging revealed a well-defined, encapsulated, intramuscular lesion suggesting a mesenchymal neoplasm. Surgical excision was performed, revealing a firm, encapsulated mass beneath the left pectoralis major muscle. Histopathology and immunohistochemistry (S-100+) confirmed the diagnosis of lipoblastoma. The postoperative course was uneventful, and the child remained well at 1-month follow-up. CLINICAL DISCUSSION: Lipoblastoma is a rare benign tumor of embryonic adipose cells, usually presenting in infancy and early childhood as painless soft swellings. It is associated with PLAG1 gene rearrangements, aiding differentiation from liposarcoma in ambiguous cases. Diagnosis relies on imaging and histopathology, with immunohistochemistry showing vimentin and S-100 positivity. Complete surgical excision is curative, though recurrence occurs in 9-25%, especially in incompletely excised or infiltrative lipoblastomatosis. CONCLUSION: Lipoblastomas, though benign and less commonly seen, are challenging since they require high clinical suspicion to differentiate lipoblastoma from liposarcoma in pediatric soft tissue masses. Surgical excision is the definitive treatment, and vigilant postoperative monitoring is mandatory to obviate the risk of recurrence.