Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Departments of Pathology, Oncology, and Urology, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
Mod Pathol. 2018 Jun;31(6):984-988. doi: 10.1038/s41379-018-0012-z. Epub 2018 Feb 6.
Osteoclast-rich undifferentiated carcinoma of the urinary tract (ORUCUT) is a rare tumor composed of ovoid to spindle-shaped mononuclear cells with intermixed or focally clustered osteoclast-like giant cells. Previous studies have demonstrated that the mononuclear cells are neoplastic cells, while the giant cells are reactive cells of histiocytic lineage. The association between these tumors and classic urothelial carcinomas suggest that the mononuclear cells are derived from urothelial cells; however, no studies have been conducted to assess the immunohistochemical profile of ORUCUT with more specific urothelial markers. This study identified 21 cases of ORUCUT and performed immunohistochemistry for GATA3, uroplakin II, and thrombomodulin along with pancytokeratin (AE1/3) on all cases. Mononuclear cells stained positive in 20 cases (95%) for GATA3 and 19 cases (90%) for thrombomodulin. None of the mononuclear cells were positive for uroplakin II and only three cases showed focal positivity for AE1/3. The osteoclast-like giant cells were negative for GATA3, uroplakin II, thrombomodulin, and AE1/3, providing additional support to a reactive origin for these cells. Additionally, 15 cases (71%) were associated with either in situ or invasive urothelial carcinoma. This study provides an expanded immunohistochemical profile for ORUCUT and more definitively supports a urothelial origin for this tumor.
富含破骨细胞的未分化尿路上皮癌（ORUCUT）是一种罕见的肿瘤，由卵圆形至梭形的单核细胞组成，混杂有或局灶性聚集的破骨样巨细胞。先前的研究表明，单核细胞是肿瘤细胞，而巨细胞是组织细胞来源的反应性细胞。这些肿瘤与经典的尿路上皮癌之间存在关联，提示单核细胞来源于尿路上皮细胞；然而，尚无研究评估 ORUCUT 与更特异的尿路上皮标志物的免疫组织化学特征。本研究鉴定了 21 例 ORUCUT，并对所有病例进行了 GATA3、尿路上皮蛋白 II 和血栓调节蛋白的免疫组织化学染色以及广谱细胞角蛋白（AE1/3）染色。20 例（95%）单核细胞 GATA3 染色阳性，19 例（90%）单核细胞血栓调节蛋白染色阳性。单核细胞均无尿路上皮蛋白 II 阳性，仅 3 例 AE1/3 局灶性阳性。破骨样巨细胞 GATA3、尿路上皮蛋白 II、血栓调节蛋白和 AE1/3 均阴性，为这些细胞的反应性起源提供了更多支持。此外，15 例（71%）与原位或浸润性尿路上皮癌相关。本研究为 ORUCUT 提供了更广泛的免疫组织化学特征，并更明确地支持了该肿瘤的尿路上皮起源。
