The pathology report should specify the presence and percentage of subtype and/or mixed histology (e.g., squamous and/or glandular differentiation, micropapillary, nested, plasmacytoid, neuroendocrine, sarcomatoid) and/or the presence or absence of LVI. These subtypes are less common but their presence influences disease prognosis and treatment choices. This combination supports the role of experienced pathologic overview.91 Although the term “variant pathology” may still be used to describe different morphological types of bladder cancer, the pathologic preferred descriptive term is histological subtypes for these morphotypes.92 The term “variant” has more commonly become associated with specific deoxyribonucleic acid (DNA) and genomic alterations. The 2022 WHO classification adopted the term “subtype” to help make this distinction.48, 93 The Panel recognizes that future pathologic subtypes and molecular variations will continue to be elucidated and that these may require secondary review. In cases of non-muscle invasive disease, re-resection is mandatory to rule out muscle-invasive disease given the high rate of upstaging with subtype histology. Several studies suggest that subtype differentiation may affect survival; however, there is a paucity of data due to the rarity of most subtypes. Some of the subtypes, such as micropapillary, have been described fairly recently (1994), and others are under-recognized or understaged.94 In one study from the Mayo Clinic, pathological re-review of cystectomy specimens identified subtype histologies in up to one third of patients initially classified with pure urothelial carcinoma.95 Compared to patients with pure urothelial carcinoma, those with subtype histology have a greater incidence of locally advanced disease and worse survival.96-98 The diagnosis of LVI is defined by the presence of tumor within endothelium-lined spaces. Numerous studies have documented the clinical importance of LVI as an important prognostic marker of upstaging, lymph node involvement, recurrence, and decreased overall survival.28-31 Thus, the Panel believes that the reporting of the presence or absence of LVI is important. Molecular subtypes (e.g., luminal, basal-squamous) may play a future role in determining prognosis, prediction, and treatment option but currently remain investigational.