Pathology Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany.
Histopathology. 2020 Aug;77(2):231-239. doi: 10.1111/his.14110. Epub 2020 Jul 2.
Anaplastic carcinoma arising in a mucinous tumour of the ovary and rarely in the retroperitoneum is an uncommon neoplasm with three morphological patterns; rhabdoid, sarcomatoid and pleomorphic. We investigated expression of switch/sucrose non-fermentable (SWI/SNF) chromatin remodelling complex components and claudin-4 expression.
Twenty-two ovarian and three retroperitoneal mucinous tumours were investigated using antibodies against SMARCB1, SMARCA4, SMARCA2, ARID1A and claudin-4. Loss of nuclear staining for any SWI/SNF protein was observed in the anaplastic component of nine of 25 (36%), with retained expression within the mucinous component of all tumours. Five (56%) showed loss of more than one protein, with dual loss of SMARCA4 and SMARCA2 in two, loss of SMARCA2 and ARID1A in two and loss of SMARCB1 and SMARCA2 in one. Retained expression of claudin-4 was seen in 39% of the anaplastic carcinomas and within the mucinous component of all tumours. Rhabdoid morphology was associated with poor prognosis [stages III or IV disease (six of six, 100% versus four of 14, 29%; P = 0.0108] and death from disease (three of four, 75% versus one of 13, 8%; P = 0.0223). Although loss of a SWI/SNF protein was not significantly associated with death from disease (three of five, 60% versus one of 12, 8%; P = 0.0525), it showed a trend in correlation with poor prognosis and was often noted in tumours with rhabdoid morphology within this small cohort.
Our report adds to the growing list of female genital tract malignancies with loss of SWI/SNF proteins, underlining their broad differential diagnosis and the importance of careful, context-dependent interpretation of SWI/SNF protein loss.
卵巢黏液性肿瘤和罕见于腹膜后发生的间变性癌是一种少见的肿瘤，具有 3 种形态学模式：横纹肌样、肉瘤样和多形性。我们研究了 SWI/SNF 染色质重塑复合物成分和 Claudin-4 的表达。
使用针对 SMARCB1、SMARCA4、SMARCA2、ARID1A 和 Claudin-4 的抗体，对 22 例卵巢和 3 例腹膜后黏液性肿瘤进行了研究。在 25 例中的 9 例（36%）的间变性成分中观察到任何 SWI/SNF 蛋白的核染色丢失，而所有肿瘤的黏液性成分均保留表达。有 5 例（56%）显示不止一种蛋白丢失，其中 2 例同时丢失 SMARCA4 和 SMARCA2，2 例丢失 SMARCA2 和 ARID1A，1 例丢失 SMARCB1 和 SMARCA2。 Claudin-4 的保留表达见于 39%的间变性癌和所有肿瘤的黏液性成分中。横纹肌样形态与不良预后[III 或 IV 期疾病（6/6，100%比 14 例中的 4 例，29%；P=0.0108]和疾病死亡相关（4/4，75%比 13 例中的 1 例，8%；P=0.0223）。尽管 SWI/SNF 蛋白的丢失与疾病死亡无显著相关性（5 例中的 3 例，60%比 12 例中的 1 例，8%；P=0.0525），但在本小队列中，它与不良预后呈相关性趋势，且常发生于具有横纹肌样形态的肿瘤中。
我们的报告增加了女性生殖道恶性肿瘤中丢失 SWI/SNF 蛋白的病例，强调了它们广泛的鉴别诊断和谨慎、上下文相关的 SWI/SNF 蛋白丢失解读的重要性。
