Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma of the Orbit: Three Cases and Review of the Literature.

The authors present 3 patients from this retrospective case series to review the clinical findings, imaging, pathology, and treatment of orbital atypical lipomatous tumor/well-differentiated liposarcoma. Pathology of biopsy specimens ranged from spindle cell proliferations mimicking neurofibroma to proliferations of well-differentiated adipocytes. Immunohistochemical stains were positive for murine double minute 2 in 1 case, and fluorescent in situ hybridization showed amplification of murine double minute 2 in 2 cases. Treatments ranged from serial debulking, proton beam irradiation, and exenteration. None of the patients developed metastases. A literature review supported the low-grade nature of this lesion. Orbital atypical lipomatous tumor/well-differentiated liposarcoma is a low-grade, indolent liposarcoma that may be locally invasive. The histologic diagnosis is enhanced with immunohistochemical staining for murine double minute 2 and fluorescent in situ hybridization analysis for amplification of murine double minute 2. Although treatment may vary according to the individual, conservative therapies may be attempted prior to radical surgery.