AIM To explore the cytological spectrum of the gastrointestinal stromal tumour (GIST) including its metastatic sites. MATERIAL AND METHODS A total of 42 patients (45 sites) diagnosed with GIST or its metastases on fine needle aspiration cytology were studied over a period of 5 years. May-Grünwald Giemsa- and haematoxylin and eosin-stained smears were reviewed and analysed for the cytomorphological spectrum of GIST. RESULTS Primary GIST alone was seen in 24 cases, E-GIST in eight cases and metastasis in 11 cases (one patient showing metastasis at two distinct sites), whereas concurrent primary and metastatic lesions were noted in two cases. Amongst primary sites, the most commonly affected location was stomach (n = 22), followed by ileum (n = 2), duodenum (n = 1) and rectum (n = 1). Extra-GIST was seen in retroperitoneum and pelvis (n = 3 each), omentum and mediastinum (n = 1 each). Fine needle aspiration cytology was done from 11 metastatic sites of GIST which included liver, gall bladder fossa, chest wall, and thigh. The classic spindle cell arrangement was the predominant cytological pattern. About 8.8% cases showed predominant epithelioid cell morphology and 15.5% cases had a mixed cytomorphology comprising of both spindle cell and epithelioid cell patterns. Nuclear pseudoinclusions, perinuclear vacuoles and multinucleation were seen in four cases. Immunocytochemistry on cell-block sections for confirmation was performed in 18 cases and all these cases showed strong c-KIT positivity. CONCLUSION In this largest case series of cytomorphological diagnosis of GIST, we describe the cytomorphology and immunocytochemistry of primary and metastatic GIST. GISTs with predominant epithelioid cell morphology may pose a diagnostic dilemma therefore in all suspected cases of GIST, immunocytochemistry for c-KIT and/or DOG1 should be employed on cell-block preparations to confirm the diagnosis of GIST.

中文翻译：

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原发性和转移性胃肠道间质瘤的细针穿刺细胞学检查。

目的探讨胃肠道间质瘤（GIST）的细胞学谱及其转移部位。材料与方法在5年的时间里，研究了总共42例（45个部位）经细针穿刺细胞学诊断为GIST或其转移的患者。对May-GrünwaldGiemsa和苏木精以及曙红染色涂片进行了检查，并分析了GIST的细胞形态学谱。结果仅发现原发性GIST 24例，E-GIST 8例，转移11例（1例在两个不同部位显示转移），而2例同时发生原发和转移性病变。在主要部位中，最受影响的部位是胃（n = 22），其次是回肠（n = 2），十二指肠（n = 1）和直肠（n = 1）。在腹膜后和骨盆中观察到Extra-GIST（n = 3），网膜和纵隔（n = 1）。细针穿刺细胞学检查是从GIST的11个转移部位进行的，包括肝脏，胆囊窝，胸壁和大腿。经典的纺锤体细胞排列是主要的细胞学模式。约有8.8％的病例表现出主要的上皮样细胞形态，有15.5％的病例具有混合的细胞形态，包括梭形细胞和上皮样细胞模式。在四例中可见核假包涵体，核周液泡和多核。在18例细胞块切片上进行免疫细胞化学检查以确认，所有这些病例均显示强c-KIT阳性。结论在GIST细胞形态学诊断的最大案例系列中，我们描述了原发性和转移性GIST的细胞形态学和免疫细胞化学。