Atypical Spindle Cell and Pleomorphic Lipomatous Tumor of the Ocular Adnexa: Two Cases of a Rare Entity

Abstract

: Atypical spindle cell and pleomorphic lipomatous tumor (ASCPLT) is a rare lipomatous neoplasm that was recently introduced into the World Health Organization Classification of Soft Tissue and Bone tumors as a distinct entity. ASCPLT has potential for local recurrence but does not metastasize. This biologic behavior separates ASCPLT from its morphologic mimics. Ocular adnexal ASCPLT has not been previously reported. Described herein are two patients with ASCPLT. The subcutaneous orbital rim lesion featured markedly pleomorphic spindle and multinucleated cells. The eyelid lesion was dominated by atypical spindle cells in a background of mature adipocytes. Both neoplasms demonstrated infiltrative margins, rare mitotic figures, immunoreactivity for CD34 and loss of Rb1, and the absence of MDM2 amplification by fluorescence in situ hybridization. Recognition of ASCPLT in the differential of ocular adnexal neoplasms may lead to a re-evaluation of morphologically similar tumors, which may have varied biologic behavior and warrant a different management approach.

Atypical Spindle Cell/Pleomorphic Lipomatous Tumor of the Orbit: A Case Report

“…A large series of 232 atypical spindle cell lipomatous tumors reported that approximately two-thirds (63%) of the tumors occur predominantly in the limbs and limb girdles, although less commonly in the head and neck, genital area, trunk, and back [ 2 ]. To the best of our knowledge, ASC/ PLT in the ocular adnexa has been previously reported in only two cases: the orbital septum and eyelid [ 3 ]. According to Ulloa-Padilla et al [ 3 ], our tumor is differentiated from the other atypical lipomatous tumor/well-differentiated liposarcoma since MDM2 and CDK4 showed negative in immunohistochemical findings.…”

“…To the best of our knowledge, ASC/ PLT in the ocular adnexa has been previously reported in only two cases: the orbital septum and eyelid [ 3 ]. According to Ulloa-Padilla et al [ 3 ], our tumor is differentiated from the other atypical lipomatous tumor/well-differentiated liposarcoma since MDM2 and CDK4 showed negative in immunohistochemical findings.…”