T3 Gallbladder Carcinoma With Pancreaticobiliary Maljunction, Initially Diagnosed With Adenomyomatosis.

Adenomyomatosis of the gallbladder (ADM) is generally considered benign. Key imaging features of ADM show cystic spaces in the subserosa of a thickened gallbladder wall, corresponding to dilated Rokitansky-Aschoff sinuses. This case was initially diagnosed with ADM via ultrasound and monitored for 6 years without further investigations due to the absence of significant changes or symptoms. However, after symptom onset, ultrasound revealed T3 gallbladder carcinoma, and endoscopic retrograde cholangiopancreatography first identified pancreaticobiliary maljunction (PBM). A radical operation was performed. ADM associated with PBM has been recently reported. Consequently, evaluating the presence or absence of PBM is crucial for developing an appropriate treatment strategy when diagnosing ADM.