Diagnosis of bladder diverticular tumor by transrectal biplanar ultrasonography: a case report.

Introduction: Diverticular carcinoma of the bladder is an uncommon urological disease, and its imaging diagnosis prior to surgical intervention can be difficult. Case presentation: An elderly male patient was found to have an unidentified mass within the right wall diverticulum of the bladder during a physical examination. Given that the lesion was located in the posterior wall of the bladder, transrectal biplane ultrasound showed that this abnormality was bulging outwards with incomplete separation, and there was an inhomogeneous echo measuring about 8 × 9 × 13 mm. Color Doppler flow imaging detected arterial blood flow at the wide base and obscure boundary of the inhomogeneous echo. Subsequently, diverticulectomy combined with partial cystectomy was performed. Postoperative pathology and immunohistochemistry supported the diagnosis of intestinal-type adenocarcinoma. Clinical discussion: This case is a very rare intestinal-type adenocarcinoma arising in a bladder diverticulum. Additionally, diverticular carcinoma of the bladder is also a rare urological neoplasm that poses challenges in preoperative diagnosis. Transrectal biplane ultrasound serves as an excellent imaging modality for detecting this lesion when it is situated in the posterior wall adjacent to the rectum. Conclusion: Transrectal biplane ultrasound can clearly visualize the location, size, and internal characteristics of the diverticulum, as well as the blood flow of the inner lesion. This imaging technique played a pivotal role in determining the nature of the lesion and significantly contributed to the subsequent diagnosis and treatment planning.