INTRODUCTION Identifying metastatic breast carcinoma (mBC) in malignant effusion cytology (MEC) specimens is critical, as this will determine the patient's prognosis and therapeutic management. Overlapping cytomorphologic features of breast carcinoma (BC) with other neoplastic entities makes the use of sensitive and specific markers highly desirable. Recent studies have reported trichorhinophalangeal syndrome type 1 (TRPS1) as a sensitive and specific marker for primary BC and mBC. We aimed to investigate TRPS1 expression in MEC of mBC and its most common diagnostic mimickers. MATERIALS AND METHODS A retrospective search from the pathology archives identified 82 MEC. TRPS1 expression in mBC was analyzed, and the results were compared to those in metastatic carcinoma of Müllerian origin (mMC) and metastatic pulmonary adenocarcinoma (mPAC). TRPS1 immunoperoxidase was performed on cytospin or cell block preparations, and p < 0.05 was considered significant. RESULTS Nuclear expression for TRPS1 was evaluated and scored as positive (≥1% of tumor cells) or negative. Nuclear TRPS1 expression was seen in 100% (30/30) mBC, 72% (18/25) mMC, and 7% (2/27) mPAC. This resulted in sensitivity, specificity, positive predictive value, and negative predictive values of 100%, 61%, 60%, and 100%, respectively. CONCLUSION TRPS1 is a sensitive marker for mBC and can be reliably performed on cytology specimens. TRPS1 expression was also identified in a significant proportion of mMC, creating a potential diagnostic pitfall. Therefore, caution should be exercised when evaluating MEC of mBC with TRPS1. Consequently, a combination of immunoperoxidase panels should be employed in this setting.

中文翻译：

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TRPS1 在恶性渗出液细胞学中的应用。

引言 在恶性渗出液细胞学 (MEC) 标本中识别转移性乳腺癌 (mBC) 至关重要，因为这将决定患者的预后和治疗管理。乳腺癌 (BC) 与其他肿瘤实体的细胞形态学特征重叠，因此非常需要使用敏感和特异性标记物。最近的研究报道了 1 型毛鼻指综合征 (TRPS1) 作为原发性 BC 和 mBC 的敏感和特异性标志物。我们旨在研究 TRPS1 在 mBC 的 MEC 及其最常见的诊断模拟物中的表达。材料和方法 对病理档案的回顾性搜索确定了 82 个 MEC。分析了 mBC 中的 TRPS1 表达，并将结果与​​苗勒管起源的转移性癌 (mMC) 和转移性肺腺癌 (mPAC) 中的结果进行了比较。TRPS1 免疫过氧化物酶在细胞离心涂片或细胞块制剂上进行，p < 0.05 被认为是显着的。结果 TRPS1 的核表达被评估并评分为阳性（≥1% 的肿瘤细胞）或阴性。在 100% (30/30) mBC、72% (18/25) mMC 和 7% (2/27) mPAC 中观察到核 TRPS1 表达。这导致灵敏度、特异性、阳性预测值和阴性预测值分别为 100%、61%、60% 和 100%。结论 TRPS1 是 mBC 的敏感标记物，可以可靠地对细胞学标本进行检测。在相当大比例的 mMC 中也发现了 TRPS1 表达，这造成了潜在的诊断缺陷。因此，在使用 TRPS1 评估 mBC 的 MEC 时应谨慎行事。因此，在这种情况下应结合使用免疫过氧化物酶组。