We report a rare case of overlapping immunoglobulin G4-sclerosing cholangitis (IgG4-SC) and primary biliary cholangitis (PBC) in a 78-year-old woman presenting with sudden-onset jaundice, cholestatic liver enzyme elevation, and biliary strictures. Elevated alkaline phosphatase levels, positive antimitochondrial antibodies, increased serum IgG4 levels, and a high IgG4/IgG ratio, combined with endobiliary biopsy via endoscopic retrograde cholangiopancreatography biopsy showing lymphoplasmacytic infiltration and IgG4-positive cells, confirmed the diagnosis. Initial treatment with biliary drainage, ursodeoxycholic acid (UDCA), and corticosteroids provided temporary relief; however, the patient experienced recurrent episodes of cholangitis and biliary obstruction, eventually progressing to decompensated cirrhosis over 2 years. This case highlights the importance of considering IgG4-SC in patients with PBC who fail to respond adequately to UDCA and underscores the significant challenges in diagnosing and managing such overlapping syndromes. Further research is crucial to better understand the underlying pathophysiology, refine therapeutic strategies, and improve clinical outcomes of these rare, complex autoimmune conditions.

There have been rare reports of damage to the blood vessels surrounding the bile duct during the gallstone removal process, causing hemobilia. In cases of severe hemobilia with unstable vital signs, insertion of a fully covered self-expanding metallic stent (SEMS) may be considered as salvage therapy. This case reports a patient with common bile duct stones and acute cholangitis who developed massive hemobilia during attempts to resolve basket device incarceration by performing mechanical lithotripsy. Endoscopic hemostasis was successfully achieved by insertion of a SEMS. However, during follow-up, the stent distally dislocated, resulting in rebleeding with a pseudoaneurysm in the surrounding blood vessels. Ultimately, hemostasis failed despite vascular intervention and additional hemostatic procedures, leading to death. Even if a stent is inserted in an appropriate location, hemostasis may not be achieved well, and if the stent migrates, hemobilia may worsen, so close monitoring is required to determine whether bleeding occurs again.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.

Nuclear medicine in South Korea began in 1959 with the measurement of 131I uptake and excretion in patients with thyroid diseases and has achieved remarkable progress over the past 60 years. Diagnostic nuclear medicine imaging in South Korea, introduced in 1961, has evolved to include gamma camera imaging using gamma cameras and positron emission tomography (PET) combined with computed tomography (CT), which are now established as primary diagnostic modalities. The radionuclides used in gamma cameras and PET/CT are produced by generators and cyclotrons. These radionuclides are labeled to compounds that are selectively taken up by target organs, thereby forming radiopharmaceuticals. In South Korea, some of the commonly used radiopharmaceuticals for diagnostic nuclear medicine imaging in patients with pancreaticobiliary diseases include 99mTc-dicarboxypropane diphosphonate (DPD), 99mTc-methylene diphosphonate (MDP), 99mTc-hydroxymethylene diphosphonate (HMDP), 99mTc-bromotriethyl-iminodiacetic acid (BrIDA or mebrofenin), 18F-fluorodeoxyglucose (18F-FDG), 18F-2-fluoro-3,4-dihydroxyphenylalanine (18F-FDOPA), 111In-pentetreotide (octreotide), and 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid0-Tyr3-octreotide (68Ga-DOTA-TOC), which are widely used for the diagnosis and therapeutic planning of pancreaticobiliary neoplasms. The medical radiation exposure associated with diagnostic nuclear medicine imaging is considered to be at an acceptable level compared to radiation doses from natural background radiation. When clinicians understand the characteristics and advantages of nuclear medicine diagnostic imaging and effectively communicate this information to patients, this can contribute to building trust and improving the quality of medical care.

Administering sedation for endoscopic retrograde cholangiopancreatography (ERCP) involves using medications to reduce the patient's level of consciousness during a procedure, which can alleviate patient anxiety and discomfort, and improve clinical outcomes. Due to the complexity of the procedure and physiological changes induced by the prone position, meticulous sedation management is essential during ERCP. Before the procedure, a detailed history taking and physical examination are important. If the Mallampati or American Society of Anesthesiologists classification scores are high, anesthesia provider assistance should be considered. Both standard sedation with a combination of midazolam and opioids and balanced propofol sedation can be used safely. During the procedure, monitoring of vital signs, oxygen saturation, and electrocardiogram is important. For high-risk patients, capnography should also be considered. In particular, personalized approaches, including dosage adjustments and more vigilant monitoring during the procedure, are critical for high-risk patients. To ensure safe ERCP, endoscopists must be familiar with the characteristics of sedatives, as well as the types and dosages of antagonists. To prevent hypoxia during the procedure, preoxygenation and the use of high-flow nasal cannula can be considered, and a laryngeal mask can be useful if intubation is difficult in emergency situations. Above all, care must be taken to avoid excessive doses of sedatives, and it is crucial to continually assess the necessity of ERCP for each patient.

Perihilar cholangiocarcinoma, a rare and aggressive tumor, can develop in the bile ducts at the junction of the right and left hepatic ducts. Successful treatment with of surgical excision and/or transplantation has significantly improved the management of the disease, leading to increased survival rates and better quality of life for patients. Nonetheless, challenges persist, including limited therapy options for advanced-stage disease, potential risks, and a shortage of donor organs. For early-stage disease, surgical resection, usually right hepatectomy, is the preferred treatment, while transplantation is indicated for non-resectable cases. Liver transplantation offers prolonged survival for certain individuals; however, it requires lifelong immunosuppression and carries the risk of recurrence. The choice between resection and transplantation depends on various factors, including disease stage, patient health, and the availability of a donor organ. For patients diagnosed with perihilar cholangiocarcinoma, implementing an interdisciplinary approach is crucial for optimizing therapeutic efficacy.