Rare case of lipoblastomatosis of the orbit

This article published in the November/December 2011 issue of Ophthalmic Plastic and Reconstructive Surgery reports an unusual case of lipoblastomatosis of the orbit and reviews the literature on lipoblastomatosis and lipoblastoma. Based on their findings, the authors say the ultimate prognosis for lipoblastomatosis remains unknown. While most cases do well without recurrence after complete resection, reports of maturation in mature fat and the rare instance of spontaneous regression suggest that radical surgery may not be necessary in all cases.

Lipoblasotoma is a rare, benign lipomatous tumor of childhood representing four to five percent of pediatric adipose tumors. Lipoblastomas are believed to arise from altered embryogenesis of human white fat and should be included in the differential of orbital fatty tumors. They are typically well-circumscribed lesions. Lipoblastomatosis are similar on histology but have a more diffuse growth pattern. However, the treatment of both is surgical, with most authors recommending complete surgical excision for tumor control.

Cytogenetic analysis provides the best means of distinguishing lipoblasotmas from myxoid liposarcoma. Lipoblastomas have translocations involving 8q11-13 while myxoid liposarcomas have translocations involving chromosomes 12 and 16.

The authors describe the case of a 9-year-old girl originally diagnosed with preseptal cellulitis. After failure of systemic therapy, a CT scan showed a mass in the orbit. Biopsy of the lesion confirmed the presence of lipoblastomatosis, consisting of immature lipoblasts admixed with more mature adipocytes. The patient remained asymptomatic, without evidence of recurrence, 50 months after surgery.

Histopathology showed poorly defined fat lobules with a fine plexus of capillaries and venules. Undifferentiated mesenchymal cells and primitive fibroblasts were present in a myxedematous stroma, as were adipose cells in varying degrees of maturation.

The literature review identified 410 previous cases of lipoblastoma and lipoblastomatosis. Sixty-eight percent of these were encapsulated and represented lipoblastoma. The remaining 32 percent showed a more-diffuse growth pattern, more consistent with lipoblastomatosis.

The tumors occurred most frequently on the trunk and extremities (80 percent) and much less commonly on the head and neck (17 percent). Of the latter group, most were seen in the neck, with only 5 percent occurring on the face and head. Only three previous cases of lipoblastoma have been reported around the eyes.