CASE SERIES ON ‘LIPOBLASTOMA’, A RARE TUMOUR IN CHILDREN

Abstract

Purpose of Study: To discuss on Clinical presentations, Investigations, Histopathology, Differential diagnosis and Treatment options based on a series of six Lipoblastomas that we encountered in our paediatric orthopaedic practice.

Materials and Methods: This series consists of six children with lipoblastoma who attended Alder Hey Hospital between 2000 and 2006. Mean age 17 months. Mean follow up was 26 months. The youngest was a six month old infant with a swelling on his right instep. The second patient was a three year old girl who presented with a limp and swelling in her foot, the third patient was an 18 month old boy with a swelling on the dorsum of his left forearm, fourth patient had a swelling of his left thigh and two patients had swellings in their back. They were investigated appropriately with MRI, CT or USG and surgical excision planned accordingly.

Results: Male to female ratio was 5:1. Age groups; 2 patients were of less than 12 months of age, another two of them was between 12 to 24 months and the last two were under 36 months at the time of diagnosis. Anatomically three patients had swellings in the lower limb, 2 had swellings over dorsum of their trunk one patient had a forearm swelling.

Investigations include MRI for one patient and CT for another USG was done for the remaining four. There was no post op complication for any of them. None of them have shown any recurrence during the follow-up.

Discussion: Lipoblastomas are uncommon, benign tumour of embryonal mesenchymal cells. It is a rare tumour but occurs mostly during infancy and early childhood. It most often presents on the extremities, back, head and neck.

Histology: cellular neoplasm composed of lipoblasts in different stages of maturation and fine vascular network, with well defined septa.

Cytogenetic evaluation often shows chromosomal anomalies of tumour cells like abnormalities of the long arm of chromosome 8, leading the rearrangement of the PLAG1 gene. Biopsy of the lesion is recommended, as clinical and radiological diagnoses can be misleading.

These tumours tend to spread locally and may recur in case of incomplete resection; metastatic potential has not been reported.

Differential diagnosis includes myxoid liposarcoma, welldiffrentiated liposarcoma, spindle cell lipoma, typical lipoma and soft tissue sarcoma.

Conclusion: All patients were originally thought to have simple lipomas or soft tissue swellings. This is primarily because lipoblastoma is a rare tumour and is rarely encountered in orthopaedic training. It is important that we orthopaedic surgeons be aware that lipoblastoma is in fact the most likely diagnosis of a fatty lump in a child of less than two years of age. Lipoblastomas needs through imaging and if possible cytogenetic evaluation for accurate diagnosis before surgery because complete surgical resection is mandatory to prevent a likely local recurrence.