Inverted lesions in the urinary bladder have been the source of some difficulty in urological pathology. The two common ones are von Brunn＇s nests and cystitis cystic/cystitis glandularis, which are considered normal...Inverted lesions in the urinary bladder have been the source of some difficulty in urological pathology. The two common ones are von Brunn＇s nests and cystitis cystic/cystitis glandularis, which are considered normal variants of urothelium. Apart from them, a number of other rare urothelial lesions with inverted growth pattern occur in the urinary bladder. Some of them are only reactive conditions, just as pseudocarcinomatous hyperplasia. Some are benign tumors, namely inverted papilloma. Whereas others are malignant neoplasms, including inverted papillary urothelial neoplasm of low malignant potential （PUNLMP）, non-invasive inverted papillary urothelial carcinoma （low-grade and high-grade）, and invasive urothelial carcinoma （inverted, nested and big nested variants）. Because of the overlapping morphological features of all the inverted lesions mentioned above, even between high-grade invasive carcinoma and psendoearcinomatous hyperplasia which are only a kind of reactive conditions, it is very important for the surgical pathologist to recognize and be familiar with these inverted lesions in urinary bladder. In this article, we review these spectrums of inverted lesions of the urinary bladder. Emphasis is placed on histogenesis, morphology, differential diagnosis of these lesions, and the pathologic grading of the non-invasive inverted neoplasms, such as inverted papilloma, inverted PUNLMP, non-invasive inverted papillary urothelial carcinoma with low-grade, and non-invasive inverted papillary urothelial carcinoma with high-grade.展开更多
The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. ...The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. Von Brunn’s nests and cysts are submucosal benign urothelial processes, related to irritative stimuli (calculi and urinary infections), characterized by an invagination with buds and clusters of normal urothelium in the lamina propria. They are common findings in the urinary bladder of human beings, but few cases have been described in dogs and cats. We report macroscopic, histopathological and, in one case, immunohistochemical features of these rare forms in the left ureters of two cats. Macroscopic evidence during surgery of ureteral nodules in two cats was accompanied by histopathological diagnosis and, in one case, by immunohistochemical assessment. Histopathology was coherent with a rare condition characterized by nests and islands of normal urothelium in the lamina propria and submucosa, with formation of cysts and moderate focal subacute inflammation. In one case epithelial cells of the nests showed well differentiated urothelial cells with an intense immunoreactivity to pan-cytokeratin (CK AE1/AE3), CK19 in the first outer layers, a slight immunoreactivity to CK20 and a low proliferative activity using MIB-1 (Ki67).展开更多
文摘Inverted lesions in the urinary bladder have been the source of some difficulty in urological pathology. The two common ones are von Brunn＇s nests and cystitis cystic/cystitis glandularis, which are considered normal variants of urothelium. Apart from them, a number of other rare urothelial lesions with inverted growth pattern occur in the urinary bladder. Some of them are only reactive conditions, just as pseudocarcinomatous hyperplasia. Some are benign tumors, namely inverted papilloma. Whereas others are malignant neoplasms, including inverted papillary urothelial neoplasm of low malignant potential （PUNLMP）, non-invasive inverted papillary urothelial carcinoma （low-grade and high-grade）, and invasive urothelial carcinoma （inverted, nested and big nested variants）. Because of the overlapping morphological features of all the inverted lesions mentioned above, even between high-grade invasive carcinoma and psendoearcinomatous hyperplasia which are only a kind of reactive conditions, it is very important for the surgical pathologist to recognize and be familiar with these inverted lesions in urinary bladder. In this article, we review these spectrums of inverted lesions of the urinary bladder. Emphasis is placed on histogenesis, morphology, differential diagnosis of these lesions, and the pathologic grading of the non-invasive inverted neoplasms, such as inverted papilloma, inverted PUNLMP, non-invasive inverted papillary urothelial carcinoma with low-grade, and non-invasive inverted papillary urothelial carcinoma with high-grade.
文摘The aim of this work is to emphasize the importance of a differential diagnosis of von Brunn’s nests in cats from other urothelial neoplastic disorders, as transitional cell carcinoma, for a subsequent optimal care. Von Brunn’s nests and cysts are submucosal benign urothelial processes, related to irritative stimuli (calculi and urinary infections), characterized by an invagination with buds and clusters of normal urothelium in the lamina propria. They are common findings in the urinary bladder of human beings, but few cases have been described in dogs and cats. We report macroscopic, histopathological and, in one case, immunohistochemical features of these rare forms in the left ureters of two cats. Macroscopic evidence during surgery of ureteral nodules in two cats was accompanied by histopathological diagnosis and, in one case, by immunohistochemical assessment. Histopathology was coherent with a rare condition characterized by nests and islands of normal urothelium in the lamina propria and submucosa, with formation of cysts and moderate focal subacute inflammation. In one case epithelial cells of the nests showed well differentiated urothelial cells with an intense immunoreactivity to pan-cytokeratin (CK AE1/AE3), CK19 in the first outer layers, a slight immunoreactivity to CK20 and a low proliferative activity using MIB-1 (Ki67).
