Sachdeva Mandi P, Goldblum John R, Rubin Brian P, Billings Steven D
Department of Dermatology, Cleveland Clinic, Cleveland, OH 44195, USA.
Am J Dermatopathol. 2009 Jul;31(5):423-6. doi: 10.1097/DAD.0b013e3181a129b7.
Pleomorphic lipomas are benign tumors that most commonly present as subcutaneous masses in the head and neck, shoulder, or back region of middle-aged to elderly men. They are related to spindle cell lipomas based on shared cytogenetic aberrations and histologic features. When little or no fat is present, the diagnosis can be challenging. A review of 38 pleomorphic lipomas seen in consultation revealed 7 cases in which fat was present in reduced (<5%) amounts (n = 5) or absent (n = 2). Six of 7 cases were from men with a mean age of 59 years. Excluding 1 case where the site was not specified, they all presented as solitary well-circumscribed subcutaneous masses in the head and neck (n = 3) or shoulder (n = 2) region. The seventh case was an intradermal tumor from the nose of a 48-year-old woman. All displayed pleomorphic and multinucleated floret cells interspersed among bland spindle cells and ropey collagen. They were diffusely immunoreactive for CD34. Referring diagnoses, when provided, included myxofibrosarcoma, giant cell fibroblastoma, and granulomatous rosacea for the tumor from the nose; none considered pleomorphic lipomas. When fat is absent or present in reduced amounts, clinical context and identification of classic nonlipogenic components are essential for the diagnosis of pleomorphic lipomas.
多形性脂肪瘤是一种良性肿瘤，最常见于中老年男性的头颈部、肩部或背部的皮下肿块。基于共同的细胞遗传学异常和组织学特征，它们与梭形细胞脂肪瘤相关。当脂肪含量很少或不存在时，诊断可能具有挑战性。一项对会诊中见到的38例多形性脂肪瘤的回顾显示，有7例脂肪含量减少（<5%）（n = 5）或不存在（n = 2）。7例中有6例来自男性，平均年龄59岁。排除1例部位未明确的病例，其余均表现为头颈部（n = 3）或肩部（n = 2）区域孤立的、边界清楚的皮下肿块。第7例是一名48岁女性鼻部的皮内肿瘤。所有病例均显示多形性和多核小花细胞散布于温和的梭形细胞和索状胶原之间。它们对CD34呈弥漫性免疫反应。提供的转诊诊断包括鼻部肿瘤的黏液纤维肉瘤、巨细胞成纤维细胞瘤和肉芽肿性酒渣鼻；均未考虑多形性脂肪瘤。当脂肪不存在或含量减少时，临床背景和经典非脂肪生成成分的识别对于多形性脂肪瘤的诊断至关重要。
