Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium.
Cancer Research Institute Ghent (CRIG), Ghent University and Ghent University Hospital, Ghent, Belgium.
Histol Histopathol. 2020 Aug;35(8):769-778. doi: 10.14670/HH-18-210. Epub 2020 Feb 18.
Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a recently described morphologically low-grade and clinically indolent adipocytic tumor, which will be incorporated as a new tumor entity in the upcoming 5th edition of the WHO Classification of Soft tissue and Bone tumors. Histologically, ASPLTs are characterized by ill-defined tumor margins and the presence of variable proportions of mild-to-moderately atypical spindle cells, adipocytes, lipoblasts, pleomorphic multinucleated cells and a myxoid or collagenous extracellular matrix. ASPLTs can show a wide variety of microscopic appearances and there is histologic overlap with diverse mimics. The diagnosis of ASPLT can therefore be challenging. Molecular studies have shown a consistent absence of MDM2 or CDK4 amplification. On the other hand, deletions or losses of 13q14, including RB1, have been identified in a significant subset of cases. This review provides an overview of the currently known clinical and pathological features of ASPLTs, detailing its most relevant differential diagnoses.
非典型性梭形/多形性脂肪肉瘤（ASPLT）是一种新近描述的形态学低度恶性和临床惰性的脂肪细胞肿瘤，将被纳入即将出版的第 5 版世界卫生组织软组织和骨肿瘤分类中的新肿瘤实体。组织学上，ASPLTs 的特点是肿瘤边界不清晰，存在不同比例的轻度至中度非典型梭形细胞、脂肪细胞、脂肪母细胞、多形性多核细胞和黏液样或胶原性细胞外基质。ASPLTs 可以表现出各种各样的微观表现，与多种模拟物存在组织学重叠。因此，ASPLT 的诊断具有一定挑战性。分子研究表明，MDM2 或 CDK4 扩增缺失一致。另一方面，在相当一部分病例中发现了 13q14 的缺失或丢失，包括 RB1。这篇综述概述了目前已知的 ASPLT 的临床和病理特征，详细说明了其最相关的鉴别诊断。
