Background: The diagnosis of atypical cases in the effusion cytology sample often poses a challenge to the cytologists. Aims and Objectives: We evaluated the diagnostic role of MOC31 in the metastatic adenocarcinoma in effusion fluid. Materials and Methods: The cytological examination and MOC31 immunostaining in the cell block sections were carried out in 64 cases of serous effusion. A total of 23 cases showed atypical cytology, out of which suspicious for malignancy (SFM) and atypia of undetermined significance (AUS) were 19 and 4 cases, respectively. In these cases, we also performed calretinin immunostaining. The cytological features, results of MOC31 immunostaining, and follow-up data were correlated to find out the sensitivity and specificity of MOC31 immunostaining in the diagnosis of metastatic adenocarcinoma. Result: The sensitivity and specificity of MOC31 were 100%. MOC31 detected all the cases of metastatic adenocarcinoma. MOC31 showed strong positivity in 19 cases of SFM. All these cases had a malignant outcome in histopathology or follow-up data. In AUS cases, MOC31 immunostaining was negative with a benign outcome. In all the atypical but malignant cases calretinin stain showed diffuse cytoplasmic and nuclear positivity. In contrast, MOC31 showed strong membranous positivity and occasionally cytoplasmic positivity. Conclusion: MOC31 is an excellent marker of metastatic adenocarcinoma in the serous effusion. The membranous positivity of MOC31 and negative calretinin immuno­staining are helpful in atypical cytological cases to avoid the diagnostic dilemma. The MOC31 positivity is significantly useful in discrete atypical cells which are more challenging to recognize.
Acta Cytologica

中文翻译：

---

MOC31免疫染色在浆液性转移性腺癌的诊断中：特别强调非典型细胞学病例

背景：积液细胞学样本中的非典型病例的诊断通常对细胞学家构成挑战。目的和目的：我们评估了MOC31在积液中转移性腺癌中的诊断作用。材料和方法：对64例浆液性积液进行了细胞学检查和MOC31免疫染色。共有23例表现出非典型细胞学检查，其中可疑恶性肿瘤（SFM）和未确定意义的非典型性异常（AUS）分别为19例和4例。在这些情况下，我们还进行了钙网蛋白免疫染色。将细胞学特征，MOC31免疫染色结果和后续数据进行关联，以了解MOC31免疫染色在转移性腺癌诊断中的敏感性和特异性。结果：MOC31的敏感性和特异性为100％。MOC31检测了所有转移性腺癌病例。MOC31在19例SFM中显示出强阳性。所有这些病例在组织病理学或随访数据中均具有恶性结果。在AUS病例中，MOC31免疫染色阴性，结果良好。在所有非典型但恶性的病例中，钙网蛋白染色均显示弥漫性细胞质和核阳性。相比之下，MOC31表现出很强的膜阳性，偶尔也有细胞质阳性。结论：MOC31是浆液性积液中转移性腺癌的极好标志。在非典型细胞学病例中，MOC31的膜阳性和钙网蛋白免疫染色阴性有助于避免诊断难题。MOC31阳性在难以识别的离散非典型细胞中非常有用。
细胞学学报