Right upper quadrant pain is one of the most frequent reasons for consultations in the emergency room. Gallbladder pathology is among the most common etiologies and can include cholecystitis, cholelithiasis, choledocholithiasis, and cholangitis, among others. Mirizzi syndrome is a complication that manifests as hepatobiliary dysfunction due to a gallstone causing extrinsic compression of the common bile duct. However, acute cholecystitis can externally obstruct the common bile duct and mimic Mirizzi syndrome in the absence of a causative gallstone. The relevance of this syndrome lies in its timely imaging diagnosis, allowing physicians to rule out other biliary pathologies and to identify its different presentations before surgical intervention. A 72-year-old male presented with abdominal pain in the right upper quadrant for the past four days. The pain persisted, prompting his admission to the emergency department. On examination, he reported abdominal pain with a positive Murphy sign. Initial abdominal ultrasound revealed dilation of the common hepatic duct, hydrocholecyst, and thickening of the gallbladder wall. Abdominal computed tomography (CT) suggested extrinsic compression of the extrahepatic bile duct by the gallbladder. Laboratory tests revealed significant leukocytosis with neutrophilia, and inflammatory markers, including C-reactive protein and erythrocyte sedimentation rate, were elevated. Liver function tests, however, remained within normal limits, with only a slight elevation in gamma-glutamyl transferase (GGT). Magnetic resonance imaging with gadolinium ruled out neoplasia of the pancreas. A magnetic resonance cholangiopancreatography (MRCP) confirmed dilation of the extrahepatic bile duct caused by extrinsic compression from the gallbladder infundibulum at the hepatic hilum and proximal common bile duct, along with slight dilation of the intrahepatic bile duct. Hydrocholecyst and gallbladder wall thickening with signal changes due to edema were also observed. These findings confirmed an extremely rare alithiasic presentation of type I Mirizzi syndrome. The patient was offered a cholecystectomy; however, he declined surgical treatment. Conservative management was pursued, and a follow-up ultrasound performed two days later showed a significant reduction in gallbladder volume, correlating with clinical improvement.

Retrieval-based Clinical Decision Support (ReCDS) can aid clinical workflow by providing relevant literature and similar patients for a given patient. However, the development of ReCDS systems has been severely obstructed by the lack of diverse patient collections and publicly available large-scale patient-level annotation datasets. In this paper, we collect a novel dataset of patient summaries and relations called PMC-Patients to benchmark two ReCDS tasks: Patient-to-Article Retrieval (ReCDS-PAR) and Patient-to-Patient Retrieval (ReCDS-PPR). Specifically, we extract patient summaries from PubMed Central articles using simple heuristics and utilize the PubMed citation graph to define patient-article relevance and patient-patient similarity. PMC-Patients contains 167k patient summaries with 3.1 M patient-article relevance annotations and 293k patient-patient similarity annotations, which is the largest-scale resource for ReCDS and also one of the largest patient collections. Human evaluation and analysis show that PMC-Patients is a diverse dataset with high-quality annotations. We also implement and evaluate several ReCDS systems on the PMC-Patients benchmarks to show its challenges and conduct several case studies to show the clinical utility of PMC-Patients.