Department of Pathological Diagnostics, Yamagata University Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
Department of Hematology, Yamagata Prefectural Central Hospital, Yamagata, Japan.
Diagn Pathol. 2021 Jan 12;16(1):6. doi: 10.1186/s13000-020-01061-4.
Histiocytic sarcoma (HS) is a rare neoplasm showing morphological and immunophenotypic features of mature tissue histiocytes. We report a patient with nodal HS exhibiting prominent reactive eosinophilic infiltration.
A 68-year-old man presented with intermittent left lower abdominal pain and weight loss over 3 months. A computed tomography scan revealed multiple abdominal nodules. Open biopsy of the mesenteric tumors was performed for definitive diagnosis. Histologically, the tumor was comprised of a diffuse noncohesive proliferation of pleomorphic large cells, including multinucleated cells. Neoplastic cells were positive for histiocytic markers (CD68, CD163, and LIGHT) and PD-L1 but lacked markers of Langerhans cells, follicular dendritic cells, and epithelial cells. Frequent reactive inflammatory cells were intermingled in the background. Interestingly, prominent eosinophilic infiltration was also noted. Spindle neoplastic cells were prone to be present around areas with little to no eosinophilic infiltration and exhibiting fibrosis and lymphatic vessel proliferation. Conversely, polygonal neoplastic cells were prone to be present around areas with relatively large amounts of eosinophilic infiltration without fibrosis or lymphatic vessel proliferation. Immunohistochemically, the tumor cells and reactive eosinophils expressed eotaxin-2 and eotaxin-3, respectively.
We revealed that eotaxins induced the selective migration of eosinophils into tissues in this case. These eosinophils may affect the tumor remodeling and tumor biology characteristics of HS, such as fibrosis and lymphatic vessel proliferation.
组织细胞肉瘤（HS）是一种罕见的肿瘤，表现为成熟组织细胞的形态学和免疫表型特征。我们报告了一例表现出明显反应性嗜酸性粒细胞浸润的淋巴结 HS 患者。
一名 68 岁男性因间歇性左下腹疼痛和 3 个月体重减轻就诊。计算机断层扫描显示多个腹部结节。为明确诊断，对肠系膜肿瘤进行了开放性活检。组织学上，肿瘤由弥漫性非黏附性多形性大细胞增生组成，包括多核细胞。肿瘤细胞阳性表达组织细胞标志物（CD68、CD163 和 LIGHT）和 PD-L1，但缺乏朗格汉斯细胞、滤泡树突状细胞和上皮细胞标志物。背景中频繁出现反应性炎症细胞。有趣的是，还明显注意到嗜酸性粒细胞浸润。梭形肿瘤细胞容易出现在嗜酸性粒细胞浸润少或无的区域，并表现出纤维化和淋巴管增生。相反，多边形肿瘤细胞容易出现在嗜酸性粒细胞浸润较多但无纤维化或淋巴管增生的区域。免疫组化染色显示，肿瘤细胞和反应性嗜酸性粒细胞分别表达嗜酸性粒细胞趋化因子 2 和 3。
我们揭示了在这种情况下，嗜酸性粒细胞趋化因子诱导嗜酸性粒细胞选择性迁移到组织中。这些嗜酸性粒细胞可能影响 HS 的肿瘤重塑和肿瘤生物学特征，如纤维化和淋巴管增生。
