Simulators of Urothelial Carcinoma

Abstract

A broad spectrum of lesions, including hyperplastic, metaplastic, inflammatory, infectious, and reactive, may mimic cancer all along the urinary tract. This narrative collects most of them from a clinical and pathologic perspective offering urologists and general pathologists their most salient definitory features. Together with classical, well-known, entities such as urothelial papillomas (conventional and inverted), nephrogenic adenoma, polypoid cystitis, fibroepithelial polyp, prostatic-type polyp, verumontanum cyst, xanthogranulomatous inflammation, reactive changes secondary to BCG instillations, schistosomiasis, keratinizing desquamative squamous metaplasia, post-radiation changes, vaginal-type metaplasia, endocervicosis/endometriosis (müllerianosis), malakoplakia, florid von Brunn nest proliferation, cystitis/ureteritis cystica and glandularis, among others, still other cellular proliferations with concerning histological features and poorly understood etiopathogenesis like IgG4-related disease, PEComa, and pseudosarcomatous myofibroblastic proliferations (post-operative spindle cell nodule, inflammatory myofibroblastic tumor), are reviewed. Some of these diagnoses are problematic for urologists, other for pathologists, and still others for both. Interestingly, the right identification of their definitory features will allow their correct diagnoses thus avoiding overtreatment. The literature selected for this review also focuses on the immunohistochemical and/or molecular data useful to delineate prognosis.

Malakoplakia and xanthogranulomatous pyelonephritis treated with nephrectomy

“…MKP of the bladder has also been found in association with bladder tumors with or without a history of infection [4] . This is indicating that accurate identification of MKP could be especially important in the context of a suspicion of malignancy [4] .…”

“…[ 4 ] This is indicating that accurate identification of MKP could be especially important in the context of a suspicion of malignancy. [ 4 ] Moreover, as immunosuppression has been implicated in MKP, discontinuation of immunosuppressants may need to be considered depending on the risk-to-benefit ratio. Surgical treatment may be indicated depending on the organ (s) affected.…”

“…[3] MKP of the bladder has also been found in association with bladder tumors with or without a history of infection. [4] This is indicating that accurate identification of MKP could be especially important in the context of a suspicion of malignancy. [4] Moreover, as immunosuppression has been implicated in MKP, discontinuation of immunosuppressants may need to be considered depending on the risk-to-benefit ratio.…”