The Genitourinary Pathology Society Update on Classification and Grading of Flat and Papillary Urothelial Neoplasia With New Reporting Recommendations and Approach to Lesions With Mixed and Early Patterns of Neoplasia

Abstract

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder neoplasia with a focus on issues relevant to the practicing surgical pathologist for the understanding and effective reporting of bladder cancer, emphasizing particularly on the newly accumulated evidence post-2016 World Health Organization (WHO) classification. The work is presented in 2 manuscripts. Here, in the first, we revisit the From the

Nonmuscle-invasive bladder cancer, old problems, new insights

“…This cut-off was first suggested by Cheng et al and has been maintained since [25]. The recent GUPS paper suggested a cut-off of 10%, based on the available data, mixed tumors with < 10% high grade could be diagnosed as non-invasive low-grade papillary urothelial carcinoma with a focal (< 10%), noninvasive higher-grade component [26 ▪▪ ]. Nevertheless, once again we lack prospective data.…”

Molecular uropathology and cancer genetics for the urologist: key findings for classification and diagnosis

“…Although this classification has gained much attention, international organizations, including EAU, ESMO and the Genitourinary Pathology Society do not yet recommend it in daily practice, mainly due to the lack of prospective data [14,15]. Indeed, the 5th edition of the WHO tumor classification handbook confirms that conventional surgical pathology currently remains the gold standard in tumor diagnosis and classification [1].…”

Brief update of the new WHO classification for urothelial carcinoma

“…These lesions (corresponding to what was earlier called flat hyperplasia) are thought to be benign. They can exhibit discrete papillary aspects without fibrovascular cores and may be considered shoulder lesions in the context of pTa tumors [19 ▪▪ ]. Chromosome alterations in chromosome 9 have been described, as detailed in a recently released paper published by Genitourinary Society of Pathology (GUPS) paying more attention to these lesions [19 ▪▪ ].…”

“…They can exhibit discrete papillary aspects without fibrovascular cores and may be considered shoulder lesions in the context of pTa tumors [19 ▪▪ ]. Chromosome alterations in chromosome 9 have been described, as detailed in a recently released paper published by Genitourinary Society of Pathology (GUPS) paying more attention to these lesions [19 ▪▪ ]. GUPS suggest to replace the term ‘hyperplasia’ with ‘atypical urothelial proliferation (AUP)-flat’ in case of a flat lesion, or alternatively, if some papillary formations without fibrovascular cores are present, to call it ‘AUP-tented’ [19 ▪▪ ].…”

“…Chromosome alterations in chromosome 9 have been described, as detailed in a recently released paper published by Genitourinary Society of Pathology (GUPS) paying more attention to these lesions [19 ▪▪ ]. GUPS suggest to replace the term ‘hyperplasia’ with ‘atypical urothelial proliferation (AUP)-flat’ in case of a flat lesion, or alternatively, if some papillary formations without fibrovascular cores are present, to call it ‘AUP-tented’ [19 ▪▪ ]. This terminology has not been incorporated in the WHO or approved by official organizations yet, but it is accurately descriptive and will probably soon find its way into the official terminology of uropathology.…”