Conway Andrea B, Hart Melissa K, Jessurun Jose, Pambuccian Stefan E
Department of Laboratory Medicine and Pathology, University of Minnesota, Mayo MMC 609, 420 Delaware Street SE, Minneapolis, Minnesota 55455, USA.
Diagn Cytopathol. 2013 Mar;41(3):247-52. doi: 10.1002/dc.21770. Epub 2011 Oct 11.
Large three-dimensional cell aggregates and psammoma bodies are usually encountered in benign serous effusions (mesothelial hyperplasia and endosalpingiosis), mesotheliomas, and metastatic papillary carcinomas. We report a case of pulmonary small-cell carcinoma occurring in an 88-year-old woman that initially presented with a malignant pleural effusion characterized cytologically by a predominance of large three-dimensional neoplastic cell aggregates ("cannonballs"), associated with rare psammoma bodies. Although the crowded three-dimensional tumor-cell aggregates did not allow detailed cytologic examination, the diagnosis of metastatic small-cell carcinoma could be established noting the characteristic chromatin features of the occasional single neoplastic cells and the characteristic "cell-in-cell" and "stack-of-coins" arrangements of rare small clusters of neoplastic cells. Immunoperoxidase stains showing positivity of the tumor cells for CD56, synaptophysin, and TTF1 further supported this diagnosis. Endobronchial ultrasound-guided fine-needle aspiration of a mediastinal lymph node subsequently confirmed the diagnosis of pulmonary small-cell carcinoma. Metastatic pulmonary small-cell carcinoma should be considered in the differential diagnosis of serous effusions showing large three-dimensional neoplastic cell aggregates and psammoma bodies to prevent a potential diagnostic pitfall.
大的三维细胞聚集体和砂粒体通常见于良性浆液性积液（间皮增生和输卵管内膜异位症）、间皮瘤及转移性乳头状癌。我们报告一例88岁女性发生的肺小细胞癌，最初表现为恶性胸腔积液，细胞学特征为以大的三维肿瘤细胞聚集体（“炮弹”）为主，伴有罕见的砂粒体。尽管密集的三维肿瘤细胞聚集体不允许进行详细的细胞学检查，但注意到偶尔单个肿瘤细胞的特征性染色质特征以及罕见小簇肿瘤细胞的特征性“细胞中细胞”和“硬币堆叠”排列，可确立转移性小细胞癌的诊断。免疫过氧化物酶染色显示肿瘤细胞对CD56、突触素和甲状腺转录因子1呈阳性，进一步支持了这一诊断。随后，经支气管超声引导下对纵隔淋巴结进行细针穿刺抽吸，证实为肺小细胞癌。在鉴别诊断表现为大的三维肿瘤细胞聚集体和砂粒体的浆液性积液时，应考虑转移性肺小细胞癌，以防止潜在的诊断陷阱。
