Sethi S, Cajulis R S, Gokaslan S T, Frias-Hidvegi D, Yu G H
Department of Pathology, Northwestern University Medical School, Chicago, Illinois, USA.
Diagn Cytopathol. 1997 Feb;16(2):117-21. doi: 10.1002/(sici)1097-0339(199702)16:2<117::aid-dc4>3.0.co;2-e.
Fine-needle aspiration (FNA) is a reliable and cost-effective procedure in the evaluation and management of breast lesions. One diagnostic dilemma that may sometimes arise is the finding of signet ring cells. The isolated finding of such cells in aspirate smears may be particularly problematic in cases of low cellularity or those with otherwise benign features. Although it is generally held that such cells are almost exclusively associated with carcinoma (particularly the lobular subtype), their significance in FNA smears has never been systematically evaluated. To establish their diagnostic utility, we evaluated aspirate smears from 150 cases of histologically proven benign (77) and malignant (73) breast lesions for the presence of signet ring cells, defined as those containing a prominent intracytoplasmic vacuole with nuclear displacement. Signet ring cells were identified in 71% of malignant cases (75% of ductal carcinomas and 71% of lobular carcinomas), mostly as single cells or within small, loosely cohesive tissue fragments. Such cells also present in 6% of histologically proven benign lesions, most commonly within large tissue fragments. Many of these cells were proven to be vacuolated myoepithelial cells, based on histologic correlation and immunostaining results using anti-muscle-specific actin. On the basis of these findings, we conclude that (1) the presence of signet ring cells within small loose tissue fragments or as single cells in FNA smears should prompt close clinical follow-up (including repeat FNA and perhaps surgical biopsy), regardless of smear cellularity, (2) the presence of signet ring cells in cases of adenocarcinoma does not predict a particular tumor subtype, and (3) rare benign breast lesions may contain signet ring cells, particularly within large tissue fragments, and do not, in isolation, warrant surgical biopsy to exclude malignancy.
细针穿刺抽吸活检（FNA）是评估和处理乳腺病变的一种可靠且经济有效的方法。有时可能会出现的一个诊断难题是发现印戒细胞。在细胞量少或具有其他良性特征的病例中，抽吸涂片单独发现此类细胞可能特别棘手。尽管一般认为此类细胞几乎仅与癌（特别是小叶型）相关，但其在FNA涂片中的意义从未得到系统评估。为确定其诊断效用，我们评估了150例经组织学证实为良性（77例）和恶性（73例）乳腺病变的抽吸涂片，以确定是否存在印戒细胞，印戒细胞定义为含有一个明显的胞质内空泡且细胞核移位的细胞。在71%的恶性病例中发现了印戒细胞（导管癌的75%和小叶癌的71%），大多为单个细胞或存在于小的、松散聚集的组织碎片中。此类细胞也存在于6%的经组织学证实的良性病变中，最常见于大的组织碎片内。根据组织学相关性以及使用抗肌肉特异性肌动蛋白的免疫染色结果，许多此类细胞被证实为空泡化的肌上皮细胞。基于这些发现，我们得出结论：（1）FNA涂片中在小的松散组织碎片内或作为单个细胞存在印戒细胞时，无论涂片细胞量如何，均应促使密切的临床随访（包括重复FNA以及可能的手术活检）；（2）腺癌病例中存在印戒细胞并不能预测特定的肿瘤亚型；（3）罕见的良性乳腺病变可能含有印戒细胞，特别是在大的组织碎片内，单独出现时并不需要手术活检以排除恶性肿瘤。
