Primary Signet Ring Cell Mucinous Adenocarcinoma of the Urinary Bladder: A Rare Case Report

Abstract

Primary ‘signet ring mucinous adenocarcinoma’ is most commonly located in the stomach. The bladder is an uncommon presentation site for the primary location of this tumor. Mucinous signet-ring adenocarcinoma with urinary bladder as the primary origin is uncommon, accounting for fewer than two percent of all upper urinary tract carcinomas. The presence of signet ring cells, which is caused by compression and displaced nucleus of the cell into a crescent placed in the periphery along the cell wall, is a distinguishing feature of signet ring cell carcinoma. These cells are loaded with cytoplasmic mucus-containing vacuoles. Lower than one-third of primary bladder signet ring cell carcinoma cases show this gross morphology showing linitis plastica pattern with subepithelial infiltration without producing an exophytic mass in a pure signet ring cell carcinoma. Because this tumor shares histological features with the adenocarcinomas originating in several other sites, such as the prostate, digestive tract, and reproductive system, immunohistochemistry tests are required to confirm the bladder as the primary origin. Owing to the paucity of the neoplasm and the difficulty in locating the underlying tumor, site identification is frequently prolonged, leaving palliative care as the only choice for roughly half of the patients. This study depicts a rare case report of primary vesicular signet ring cell mucinous adenocarcinoma that considerably invades the pelvis and retroperitoneum's prostate and lymph nodes. This case emphasizes the significant characteristics of bladder mucinous adenocarcinoma, such as the sequence of tumor spread, the propensity for preliminary diagnostic errors, the microscopic pattern, and the significance of immunohistochemistry for defining its primary root from the bladder and selecting the most suitable intervention from the start.