Pathology Section, Dubai Hospital, Dubai, UAE.
Cytology Unit, Dubai Hospital, Dubai, UAE.
Diagn Cytopathol. 2024 Dec;52(12):E279-E285. doi: 10.1002/dc.25399. Epub 2024 Aug 27.
Sarcomatous serous effusions are uncommon and diagnostically challenging. Dedifferentiated and pleomorphic liposarcomas are rare tumors in pleural effusions revealing highly pleomorphic tumor cells mimicking carcinoma, mesothelioma, melanoma, and other sarcomas. Hematothoracic effusions further complicate the cytologic diagnosis. Correct cytologic recognition is important. We report pleomorphic liposarcoma cytologically detected in effusion fluid in a 56-year-old man who presented with a massive unilateral pleural effusion. ThinPrep showed hemorrhagic effusion fluid characterized by lysed red blood cells, foamy macrophages, and siderophages intermixed with highly pleomorphic predominantly naked mononuclear and giant nuclei. The aggregated siderophages and vacuolated macrophages could be mistaken for tumor cells, whereas the bare nuclei may be missed as nonspecific degenerate changes. Cellblock sections showed highly pleomorphic mononuclear and multinucleated giant tumor cells with diagnostic lipoblasts, intermixed with foamy macrophages and siderophages. Cellblock immunocytochemistry showed staining for vimentin and S-100 protein in the tumor cells. Other lineage-specific immunomarkers were negative. CD68 and calretinin revealed frequent background macrophages and scarce mesothelial cells. The tumor cells were negative for MDM2 and CDK4. The entertained cytopathologic diagnosis was pleomorphic liposarcoma. Core needle biopsy was procured from the mass. The histopathologic features and immunoprofile of the tissue specimen matched the cytopathologic and immunocytochemical findings confirming the cytologic diagnosis of pleomorphic liposarcoma. Pleomorphic liposarcoma is an unexpected cytologically challenging finding in effusions, particularly when compounded by pitfalls introduced by hemosiderotic fluid. Attention to certain cytologic clues mitigate pitfalls. Cellblock is a valuable diagnostic tool when integrated with relevant negative and positive immunocytochemical markers.
肉瘤性浆液性渗出物并不常见，诊断具有挑战性。去分化和多形性脂肪肉瘤是胸膜渗出物中罕见的肿瘤，其表现为高度多形性的肿瘤细胞，类似于癌、间皮瘤、黑色素瘤和其他肉瘤。血性胸腔积液进一步使细胞学诊断复杂化。正确的细胞学识别很重要。我们报告了一例 56 岁男性的病例，他因大量单侧胸腔积液就诊，细胞学检测到多形性脂肪肉瘤。ThinPrep 显示血性胸腔积液，特点是裂解的红细胞、泡沫状巨噬细胞和含铁血黄素细胞混合存在，高度多形性，主要为裸露的单核和巨核细胞。聚集的含铁血黄素细胞和空泡状巨噬细胞可能被误认为肿瘤细胞，而裸露的细胞核可能被误认为非特异性退行性改变。细胞块切片显示高度多形性的单核和多核巨细胞，伴有诊断性的脂肪母细胞，混合有泡沫状巨噬细胞和含铁血黄素细胞。细胞块免疫细胞化学显示肿瘤细胞表达波形蛋白和 S-100 蛋白。其他谱系特异性免疫标志物为阴性。CD68 和钙视网膜蛋白显示经常出现背景巨噬细胞和罕见的间皮细胞。肿瘤细胞对 MDM2 和 CDK4 呈阴性。提出的细胞学诊断为多形性脂肪肉瘤。从肿块中获得了芯针活检。组织标本的组织病理学特征和免疫表型与细胞病理学和免疫细胞化学发现相匹配，证实了多形性脂肪肉瘤的细胞学诊断。多形性脂肪肉瘤是一种意想不到的具有挑战性的细胞学渗出物发现，特别是在富含铁血黄素的液体引入陷阱时。注意某些细胞学线索可以减轻陷阱。当与相关的阴性和阳性免疫细胞化学标志物相结合时，细胞块是一种有价值的诊断工具。
