A case of polypoid and papillary cystitis mimicking an advanced bladder carcinoma with invasion of perivesical fat
A 69-year-old man was admitted to our hospital because of pain during urination and gross hematuria. There was no relevant medical history and no presenting complaints. Routine urine examination was positive for red blood cells and showed the absence of white blood cell, protein, and glucose. Blood urea, serum creatinine, and other biochemical blood tests showed no abnormal findings. There was no clinical sign of infection and no history of bladder catheterization. Ultrasound showed an irregular and isoechoic thickening of the left side of the bladder wall. Cystoscopic examination suggested a broad expanding mass on the left side of the bladder wall. Pre- and postcontrasted CT images revealed an irregular thickening of the left side of the bladder wall and an increased density of a surrounding fat tissue []. The irregular wall thickening showed isointensity relative to the bladder wall on T1-weighted images [], and inhomogeneous hypointensity on T2-weighted images [], and gradual and inhomogeneous enhancement were seen on dynamic contrast study []. In addition, there was obliteration of the normal hypointensity of the muscle layer of the bladder wall on T2-weighted images []. Furthermore, T1- and T2-weighted images including dynamic contrast study showed a stranding of perivesical fat [Figure and ], which suggested the perivesical fat invasion. The results of urine cytology showed no malignancy. However, imaging findings suggested an advanced bladder carcinoma invading muscle layer and perivesical fat.\nTransurethral partial resection of the bladder tumor was performed to obtain a histological diagnosis. Pathologic examination revealed a polypoid or papillary appearance of the mucosa, with submucosal edematous changes, neutrophil invasions, and granulomatous formations [Figure and ]. The patient was diagnosed as having a polypoid and papillary cystitis.\nHe was followed closely without any treatment, and both the irregular thickening of the bladder wall and the stranding of a surrounding adipose tissue nearly-disappeared on MR and cystoscopic findings after 3 months [].