细针穿刺诊断甲状腺朗格汉斯细胞组织细胞增生症细胞病理学探讨

Preoperative diagnosis of Langerhans cell histiocytosis of the thyroid gland

目的探讨细针穿刺诊断甲状腺朗格汉斯细胞组织细胞增生症（LCH）的细胞病理学特点及鉴别诊断要点。方法对4例甲状腺LCH的细针穿刺进行常规涂片并观察细胞学特点、沉渣包埋及免疫组化标记,对其中3例行BRAF V600E突变检测。结果 4例均为男性,发病年龄8~40岁,均为系统性LCH累及甲状腺,其中1例合并甲状腺乳头状癌。涂片见大量单个散在或松散聚集的组织细胞,细胞核略增大,核膜不规则,可见明显纵行核沟,核仁不明显,核分裂象少见。背景中嗜酸性粒细胞数量不等。免疫组化示肿瘤细胞S-100、CD1a和CD68（＋）,TTF-1和AE1/AE3（-）。基因突变检测BRAF V600E突变（-）。结论甲状腺LCH少见,临床表现不典型,细胞学形态易混淆,术前诊断难度高。诊断与鉴别诊断的关键在于对该疾病的认识及免疫组化的应用。

Objective To investigate the characteristics of cytopathology and imnmnocytochemistry of langerhans cell histiocytosis of the thyroid gland in the fine needle aspiration （FNA）. Methods FNA of 4 langerhans cell histiocytosis （LCH） of the thyroid gland （one coexisted with papillary thyroid carcinoma） were conventionally smeared, sedimentary embeded, and immunocytochemistry stained, with real-time PCR for BRAF mutations in 3 of these cases, and reviewe of the literatures. Results ALL 4 patients were male, with age from 8 to 40 years. FNA smears （ H＆E stained ） were hypereellular, composed of histiocytic cells arranged singly or loosely aggregated in a background of numerous of neutrophils, lymphocytes and eosinophils. The tumor cells showed moderate amounts of cytoplasm and prominent nuclear grooves, occasional mitosis were seen. Most were mononuclear and some were binucleate or multinucleated. The tumor cells were positive for CDla, S-100 and CD68, but negative for T＇FF-1, AE1/AE3. BRAF mutation was not found in these cases. Conclusion It is difficult to diagnose Langerhans cell histiocytosis of the thyroid preoperatively, the key is to keep the possibility of LCH in mind, because thyroid involvement by LCH is rare and the histologie picture can vary considerably.