Pediatr Surg Int (2002) 18: 83
Ó Springer-Verlag 2002
LETTER TO THE EDITOR
M. Chitnis á T. Steyn á P. Koeppen á V. Breckon C. Lazarus
Differentiation of a benign myxolipoma from a myxoid liposarcoma by tumour karyotyping ± a diagnosis missed
Dear Sir, A 3-year-old girl presented with a large, ®rm, central abdominal mass. After abdominal ultrasound and computed tomography, a laparotomy was performed and a 25-cm-diameter tumour arising from the mesentery of the small bowel was resected. It was reported to be a ``benign myxolipoma'' on histology. The majority of soft-tissue tumours in children are benign and of vascular or ®broblastic origin. Adipose tumours are rare in children, and approximately two-thirds of these are simple lipomas and up to 30% are lipoblastomas. Lipoblastoma is a mesenchymal tumour of fat that is clinically benign but recurs if excised incompletely. It bears striking clinical and histological similarities to myxoid liposarcoma, which is even rarer in childhood. A review of the literature has informed us that it is not possible to dierentiate between a lipoblastoma and liposarcoma on histology alone; tumour karyotyping is the only method to dierentiate the two [1, 2]. Tissue culture of a lipoblastoma shows a breakpoint in the long arm of chromosome 8. The karyotype of
M. Chitnis (&) East London Health Resource Centre, P.O. Box 12882, Amalinda, East London 5252, South Africa M. Chitnis á T. Steyn á P. Koeppen á V. Breckon á C. Lazarus Eastern Cape Paediatric Surgical Service, East London, South Africa
myxoid liposarcoma typically contains a clonal anomaly t(12:16)(q13:p11). Miller et al. recommend that when performing a biopsy of a childhood adipose-tissue tumour with unusual features such as progressive or invasive growth, fresh tissue be submitted for cell culture [2]. As we were unaware of the use of tissue culture to dierentiate lipoblastoma from liposarcoma, we were not able to predict the prognosis of our patient. We present this case to increase awareness of the need to do tissue cultures of such tumours at the time of biopsy or excision.
References 1. Miller GG, Yanchar NL, Magee JF, Blair GK (1998) Lipoblastoma and liposarcoma in children: an analysis of 9 cases and a review of the literature. Can J Surg 41: 455±458 2. Miller GG, Yanchar NL, Magee JF, Blair GK (1997) Tumor karyotype dierentiates lipoblastoma from liposarcoma. J Pediatr Surg 32: 1771±1772
