==== Front Ann Saudi MedAnn Saudi MedAnnals of Saudi Medicine0256-49470975-4466King Faisal Specialist Hospital and Research Centre 10.5144/0256-4947.2006.486asm-6-486LettersLipoblastoma and infantile lipoma Ramachandran Muthukrishnan Alshahrani Dayel Ayed Umadevi KR Correspondence: Muthukrishnan Ramachandran, Consultant Histopathologist., King Abdulla Hospital, P.O Box-60., Bisha, Kingdom of Saudi Arabia., T: 07-622 3333 ext 1220, F: 07-622 3333 ext 1149, muthukrishnan63@yahoo.comNov-Dec 2006 26 6 486 487 Copyright © 2006, Annals of Saudi Medicine2006This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. ==== Body To The Editor: A 1-year-old male Saudi child was admitted in the pediatric ward with a soft, mobile right axillary mass measuring 3×4 centimeters. No signs of inflammation were seen over the swelling, and no similar swelling was noticed on the child. His blood examination showed lymphocytosis, and the tuberculin test was negative. An excisional biopsy of the axillary mass was performed to rule out lymph node disorder. The specimen, sent to the histopathology lab in 10% buffered formalin, consisted of a fairly circumscribed, whitish yellow, lobulated fatty mass measuring 6×3×1 centimeters. The cut surface of the mass was whitish yellow, homogenous with lobulations (Figure 1). Touch imprint of the mass showed adipocytes and no lymphoid cells. Microscopic examination showed lobules of lipoblasts interspersed between spindle and stellate mesenchymal cells, and suspended in a myxoid strauma with a plexiform vascular pattern (Figure 2). Lipoblastoma are benign mesenchymal tumor of embryonic white fat, with a postnatal spectrum of differentiation, ranging from prelipoblasts and mature adipocytes. The term infantile lipoma was suggested, as it reflects many of the tumor characteristics, such as early occurrence, an ability to mature into a simple lipoma, and a benign course, as the word blastoma is associated with a more malignant nature.5 Moreover, the microscopic arborising vascular pattern, myxoid strauma, and lipoblasts, in a case of lipoblastoma, resembles myxoid liposarcoma—a malignant tumor. However, liposarcomas rarely if ever occur in infants and children, and lack the lobular organization of lipoblasts seen in lipoblastoma.6 Lipoblastoma also lack giant cells and pleomorphic nuclei.7 Ultrastructurally, cells varying in appearance from primitive mesenchymal cells to typical multivaculated lipoblasts are seen in lipoblastoma,8,9,10 and these cells are very similar to cells in myxoid liposarcoma.11 Cytogenetic studies show that infantile lipoma is associated with rearrangements of 8q and trisomy of chromosome 8.12 In contrast, the cytogenetics of myxoid liposarcoma are characterized by reciprocal translocation of t(12 :16) (q 13:9 11), which results in the rearrangement of the transcription factor gene CHOP, involved in the adipocyte differtiation.13,14,15,17 A pre-operative diagnostic test for lipoblastoma would include fine needle aspiration cytology.15 An intra-operative touch imprint and frozen section can rule out other differential diagnosis. Excision biopsy is the treatment of choice and a recurrence rate of 14% to 25 % are reported from incomplete removal.16 Figure 1 Whitish yellow, greasy, lobulated appearance of the infantile lipoma. Figure 2 Lobules of lipoblasts, showing a plexiform vascular pattern. Figure 3 A high power view of the lipoblasts. ==== Refs References 1 Bertana S Parigi GP Giuntoli M Pellagali M Battisti C Bragheri R Lipoblastoma and lipoblastomatosis in children Minerva Pediatr 1999 51 159 166 10479882 2 Hicks J Dilley A Patel D Barrish H Zhu SH Brandt M Lipoblastoma and lipoblastomatosis in infancy & childhood:histopathologic, ultrastructural and cytogenitic features Ultrastruct pathol 2001 25 321 333 11577778 3 Ratan SK Gambir A Mullick S Ratan J Lipoblastoma of neck Indian J Pediatr 2000 67 301 303 10878874 4 Harrer J Hammon G Wagner T Bolkenius M Lipoblastoma and Lipoblastomatosis:A case report of 2 cases and review of literature Eur J Pediatr Surg 2001 11 1 8 5 O’Donnell KA Catty MG Allen JE Fisher JE Lipoblastoma better termed infantile lipoma? Pediatr Surg Int 2000 16 458 461 10955594 6 Bolen JW Thorning D Benign lipoblastoma and myxoid liposarcoma: a comparitive light and electron microscopic study Am J Surg Pathol 4 163 1980 7377463 7 Chung EB Enzinger FM Benign lipoblastomatosis: An analysis of 35 cases Cancer 32 482 492 1973 4353020 8 Battifora H Nunez-Alonso C Myxoid liposarcoma, study of 10 cases Ultra struct pathol 1 157 169 1980 9 Rossouw DJ Cinti S Dikersin GR Liposarcoma. An ultrastructural study of 15 cases Am J Clin Pathol 85 649 667 1986 3706206 10 Bolen JW Thorning D Liposarcomas, A histogenitic approach to the classification of adipose tissue neoplasm Am J Surg Pathol 8 3 17 1984 6696164 11 Fletcher JA Kozakewich HP Schoenberg ML Morton CC Cytogenetic findings in pediatric adipose tumors: consistent rearrangement of chromosome 8 in lipoblastoma Genes Chromosom Cancer 6 24 1993 7680218 12 Aman P Ron D Fioretos T Heim S Arheden K Willen H Rydholm A Mitelman F Rearrangement of trancription factor gene CHOP in myxoid liposarcoma with t(12:16) (q13: p 11) Genes Chromosom Cancer 5 278 285 1992 1283316 13 Crozat A Aman P Mondahl N Ron D Fusion of CHOP to a novel RNA binding protein in human myxoid liposarcoma Nature 363 640 644 1993 8510758 14 Gibas Z Miettinen M Limon J Nedoszytko B Mrozek Roszkiewicz A Rys J Niezabitowski A Dibiec-Rychter M Cytogenetic and immunohistochemical profile of myxoid liposarcoma Am J Clin Pathol 103 20 26 1995 7817937 15 Leon ME Deschler D Wa SS Galindo LM Fine needle aspiration diagnosis of Lipoblastoma of parotid region. A case report Acta cytol 2002 46 395 404 11917592 16 Chun YS Kim WK Park KW Lee SC Jung SE Lipoblastoma J Pediatr Surg 2001 36 905 907 11381423 17 Updates on the cytogenetics and molecular genetics of bone and soft tissue tumors Lipoma, Cancer Genet Cytogenet 2004 150 93 115 15066317