Department of Pathology, Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH.
Sarcoma Unit, The Royal Marsden Hospital, London.
Am J Surg Pathol. 2022 Dec 1;46(12):1700-1705. doi: 10.1097/PAS.0000000000001962. Epub 2022 Aug 26.
Pleomorphic liposarcoma (PLPS) is a highly aggressive sarcoma comprising variable numbers of pleomorphic lipoblasts mixed with undifferentiated pleomorphic sarcoma (UPS)-like areas. Morphologic variants, such as myxofibrosarcoma-like or epithelioid, may cause diagnostic confusion, especially on a core biopsy, but there are few data on the prognostic significance of these features. A total of 120 PLPS biopsies and resection specimens were reviewed and catalogued based on the presence of myxofibrosarcoma-like, UPS-like, and epithelioid foci, in 10% increments. The clinical parameters were collected. Cases occurred in 75 males and 45 females, ranging from 8 to 98 years (median, 62.5 y). Cases arose in the extremities (n=72), trunk (n=32), head/neck (n=10), bone (n=4), mediastinum (n=1), or viscera (colon polyp, n=1). Of those with known depth (n=81), 40 were intramuscular, 34 were subcutaneous, and 7 arose in the dermis. Their sizes ranged from 1 to 24.5 cm (median, 7 cm). Of the patients with ≥1 month of follow-up (n=70), 5 had recurrence and 15 had metastasis. The 5-year overall survival and event-free survival rates were 66.2% and 63.1%, respectively. Tumors ≥5 cm had inferior overall survival compared with tumors <5 cm. The presence of epithelioid areas was also statistically significant in terms of poorer overall survival and event-free survival, while tumors with ≥50% undifferentiated pleomorphic-like areas had better overall survival. There was a trend towards poorer outcomes in tumors with necrosis (≥1%). PLPS is an aggressive adipocytic malignancy that is most commonly present in the extremities of older adults. The morphologic features of these tumors are diverse, and they may be mistaken for UPS or myxofibrosarcoma, carcinoma, and melanomas, particularly on biopsies. Tumor size, necrosis, and epithelioid morphology are associated with adverse prognosis.
多形性脂肪肉瘤（PLPS）是一种高度侵袭性的肉瘤，由数量不等的多形性脂肪母细胞与未分化的多形性肉瘤（UPS）样区域混合而成。形态学变异，如黏液纤维肉瘤样或上皮样，可能导致诊断混淆，尤其是在核心活检时，但关于这些特征的预后意义的数据很少。共回顾分析了 120 例 PLPS 活检和切除标本，根据黏液纤维肉瘤样、UPS 样和上皮样灶的存在情况，以 10%的增量进行分类，并收集了临床参数。病例发生于 75 名男性和 45 名女性，年龄 8 岁至 98 岁（中位数 62.5 岁）。病例发生于四肢（n=72）、躯干（n=32）、头颈部（n=10）、骨骼（n=4）、纵隔（n=1）或内脏（结肠息肉，n=1）。在已知深度的病例中（n=81），40 例位于肌肉内，34 例位于皮下，7 例位于真皮内。其大小为 1 厘米至 24.5 厘米（中位数 7 厘米）。在有≥1 个月随访的 70 例患者中，5 例复发，15 例转移。5 年总生存率和无事件生存率分别为 66.2%和 63.1%。肿瘤≥5 厘米者的总生存率低于肿瘤<5 厘米者。上皮样区域的存在也与总生存率和无事件生存率较差相关，而分化程度≥50%的未分化多形性样区域者的总生存率较好。肿瘤内坏死（≥1%）的存在与较差的预后相关。PLPS 是一种侵袭性的脂肪肉瘤，最常见于老年人的四肢。这些肿瘤的形态学特征多种多样，在活检时可能被误诊为 UPS 或黏液纤维肉瘤、癌和黑色素瘤。肿瘤大小、坏死和上皮样形态与不良预后相关。
