Department of Pathology, University of Texas Medical Branch, Galveston, TX.
Department of Pathology, Hackensack University Medical Center, Hackensack, NJ.
Am J Surg Pathol. 2020 Jun;44(6):765-770. doi: 10.1097/PAS.0000000000001445.
Adenosarcoma can mimic high-grade endometrial stromal sarcoma with ZC3H7B-BCOR fusion that may show entrapped glands and often exhibits diffuse BCOR expression. We encountered diffuse BCOR expression in rare adenosarcomas and sought to define its frequency among a larger cohort of these tumors. BCOR immunohistochemistry was performed on archival formalin-fixed paraffin-embedded tumor tissue in 13 of 14 adenosarcomas with and without stromal overgrowth arising in the uterus or ovary. The staining intensity and percentage of positive tumor nuclei in the mesenchymal component were evaluated. Eleven cases with sufficient tumoral tissue were subjected to fluorescence in situ hybridization for the detection of BCOR, BCORL1, NUTM1, ZC3H7B, and JAZF1 rearrangement. Three cases were subjected to targeted RNA sequencing. BCOR was expressed in 9 of 13 (70%) tumors, including 6 with and 3 without stromal overgrowth. Moderate to strong staining in >70% of cells was seen throughout in 1 low-grade and 6 high-grade tumors, 5 of which had stromal overgrowth. No staining was seen in 3 low-grade and 1 high-grade tumors with stromal overgrowth. One tumor demonstrating extensive sex cord-like differentiation and diffuse BCOR expression harbored JAZF1 and BCORL1 rearrangements. No BCOR or BCORL1 rearrangement was identified in the remaining tumors. BCOR expression is seen in most adenosarcomas with and without stromal overgrowth. BCORL1 rearrangement is seen in rare tumors with diffuse BCOR expression. Assessment of BCOR or BCORL1 rearrangement status is required in adenosarcomas demonstrating BCOR expression.
腺肉瘤可能模仿具有 ZC3H7B-BCOR 融合的高级子宫内膜间质肉瘤，可能显示被困腺体，并且通常表现出弥漫性 BCOR 表达。我们在罕见的腺肉瘤中发现了弥漫性 BCOR 表达，并试图在更大的肿瘤队列中确定其频率。对 14 例子宫或卵巢发生的腺肉瘤中 13 例进行了存档福尔马林固定石蜡包埋肿瘤组织的 BCOR 免疫组织化学染色，这些腺肉瘤有无间质过度生长。评估了间质成分中阳性肿瘤核的染色强度和百分比。对 11 例具有足够肿瘤组织的病例进行了荧光原位杂交检测 BCOR、BCORL1、NUTM1、ZC3H7B 和 JAZF1 重排。对 3 例进行了靶向 RNA 测序。BCOR 在 13 例中的 9 例（70%）肿瘤中表达，其中 6 例有间质过度生长，3 例无。在 1 例低级别和 6 例高级别肿瘤中，整个肿瘤中可见 70%以上细胞的中度至强染色，其中 5 例有间质过度生长。在 3 例低级别和 1 例有间质过度生长的高级别肿瘤中未见染色。一例表现出广泛的性索样分化和弥漫性 BCOR 表达的肿瘤具有 JAZF1 和 BCORL1 重排。其余肿瘤均未发现 BCOR 或 BCORL1 重排。BCOR 表达见于大多数有和无间质过度生长的腺肉瘤。在具有弥漫性 BCOR 表达的罕见肿瘤中可见 BCORL1 重排。在表现出 BCOR 表达的腺肉瘤中，需要评估 BCOR 或 BCORL1 重排状态。
