BACKGROUND Capnocytophaga canimorsus is a gram-negative bacillus found in the oral cavity of dogs and cats. Human infection is uncommon but can cause severe sepsis. Although classically associated with asplenia, alcohol use disorder, or immunosuppression, a substantial proportion of cases occur in patients without identifiable risk factors. Diagnosis may be delayed due to the fastidious nature of the organism and the impact of prior antibiotic exposure on culture yield. CASE REPORT A 75-year-old woman presented with fever and right upper-quadrant abdominal pain 6 weeks after right total hip arthroplasty. She had no history of animal bite but reported close contact with dogs. Initial investigations did not identify a source of infection, and empirical ceftriaxone was initiated. Blood cultures became positive after extended incubation (Day 10), with identification of C. canimorsus by MALDI-TOF mass spectrometry. Imaging studies were inconclusive for prosthetic joint infection. The patient was treated with high-dose amoxicillin for 14 days, with favorable clinical and biological outcomes. CONCLUSIONS C. canimorsus infection should be considered in patients presenting with sepsis or persistent fever and a history of dog or cat exposure, even in the absence of a bite. Close collaboration with microbiology laboratories may be required to ensure appropriate culture conditions. Clinicians should also be aware of the potential for diagnostic uncertainty in patients with recent prosthetic implants.

Traumatic rupture of a hepatic hydatid cyst is an exceptionally rare and life-threatening surgical emergency, particularly in endemic regions as Kurdistan region, Iraq. We report the case of a 19-year-old male who presented with acute right upper quadrant pain following an initially undisclosed abdominal assault. Despite unremarkable initial radiographs and laboratory investigations, bedside point-of-care ultrasound and subsequent computed tomography revealed a ruptured hepatic hydatid cyst with the characteristic 'water lily sign'. The patient rapidly developed severe anaphylactic shock, requiring aggressive resuscitation with adrenaline and corticosteroids. Emergency laparotomy confirmed a ruptured hepatic hydatid cyst, which was managed with germinal layer removal, deroofing, and peritoneal irrigation. The patient made an uneventful recovery and remains disease-free at 30-month follow-up. This case underscores that anaphylaxis may be the primary manifestation of occult hydatid disease following trauma, necessitating a high index of clinical suspicion even in the absence of a known history.

Extrapulmonary tuberculosis is a common manifestation of tuberculosis, with lymph node involvement being the most frequent form. Among its presentations, periportal lymph node involvement leading to obstructive jaundice is extremely uncommon. Jaundice developing during anti-tubercular therapy (ATT) is frequently ascribed to drug-induced hepatotoxicity, which may contribute to delays in accurate diagnosis. We report a 17-year-old male with multidrug-resistant (MDR) lymph node tuberculosis who presented with progressive jaundice and right upper quadrant abdominal pain. Laboratory evaluation showed marked conjugated hyperbilirubinemia and cholestatic enzyme elevation. Ultrasonography, contrast-enhanced computed tomography (CECT), and magnetic resonance cholangiopancreatography (MRCP) revealed a large periportal and peripancreatic coalescent lymph nodal mass compressing the common bile duct (CBD), causing upstream biliary dilatation. Differential diagnoses included drug-induced hepatitis and cholangiocarcinoma, but radiology favored tuberculous lymphadenitis. The patient underwent percutaneous transhepatic biliary drainage (PTBD), with significant clinical improvement. He was subsequently restarted on the all-oral longer MDR regimen under careful monitoring. Obstructive jaundice due to tuberculous lymphadenopathy is a rare but important entity that may mimic drug-induced hepatitis or malignancy. Early imaging, biliary decompression, and individualized ATT modification are crucial. This case also highlights the rise and fall pattern associated with evolving drug resistance.

Gallbladder agenesis is a rare congenital biliary anomaly that may mimic gallbladder pathology both clinically and radiologically. On ultrasound, it may be misinterpreted as a contracted gallbladder or cholelithiasis, potentially leading to diagnostic confusion and unnecessary surgical exploration. We report the case of a 23-year-old female who presented with right upper quadrant abdominal pain and whose initial ultrasound suggested gallstones. Because the gallbladder was not clearly visualized, magnetic resonance cholangiopancreatography (MRCP) was performed for further evaluation. MRCP demonstrated the absence of the gallbladder with otherwise normal biliary anatomy, confirming congenital gallbladder agenesis. The echogenic foci initially interpreted as gallstones were later presumed to represent artifactual echoes or adjacent soft tissue/bowel interfaces rather than true cholelithiasis. The unique contribution of this case lies in highlighting a common diagnostic pitfall in which non-visualization of the gallbladder with false-positive sonographic suspicion of stones may prompt unnecessary operative planning if biliary anatomy is not clarified. This case highlights the diagnostic importance of MRCP when the gallbladder is not visualized on ultrasound and emphasizes its role in avoiding unnecessary surgical intervention in selected equivocal cases.

Bouveret syndrome is a rare form of gallstone ileus characterized by gastric outlet obstruction secondary to impaction of a gallstone that has migrated into the gastrointestinal tract through a cholecystoduodenal fistula. It predominantly occurs in elderly patients with multiple comorbidities. Cases involving giant gallstones complicated by acute pancreatitis are exceedingly uncommon and pose significant therapeutic challenges.

Omental infarction is a rare and often under-recognized cause of acute abdominal pain. Its clinical presentation varies by location and may mimic other intra-abdominal pathologies. Small infarctions, such as the one described in this case, may not be easily detectable on imaging and can be overlooked without surgical exploration. We present the case of a multiparous woman in her mid-30s who presented to the emergency department with acute-on-chronic epigastric pain. She was taken to the operating room for presumed biliary pathology. Intraoperatively, a twisted segment of omentum adherent to the peritoneum was incidentally identified, and the patient underwent omental resection with adhesiolysis. Histopathologic evaluation revealed fat necrosis suggestive of ischemia secondary to prior torsion. This case highlights the occult nature of small omental infarctions and underscores the importance of considering this entity in the differential diagnosis during the workup of acute abdominal pain.

Paraganglioma is a rare form of tumor, with secretory and non-secretory variants. Due to the rare nature of gallbladder paraganglioma (GP), there are no definitive guidelines for management. We present the case of a 35-year-old female patient who presented with intermittent right upper quadrant abdominal pain. Preoperative imaging indicated the presence of gallstones within the gallbladder lumen. Laparoscopic cholecystectomy was performed, with pathology findings consistent with a paraganglioma. The gallbladder is a rare location to find paraganglionic tissue, with its rarity posing diagnostic challenges with a lack of clear differentiating criteria between benign paraganglionic tissue (paraganglionic rests) and benign paraganglioma tumors. Given the rare nature of this condition and the lack of definitive guidelines related to its diagnosis and management, additional documentation and awareness may assist other medical professionals in recognizing and treating paraganglionic tissue found in atypical sites with more clinical confidence.

Ciliated foregut cysts are rare congenital lesions derived from abnormal budding of the primitive foregut and are most commonly identified in the mediastinum or liver, where they may also be referred to as bronchogenic-type cysts. Occurrence within the gallbladder is extremely uncommon, with only a limited number of cases reported in the literature. We present the case of a 29-year-old male who presented with right upper quadrant abdominal pain, nausea, and vomiting. Computed tomography and ultrasound revealed a cystic lesion adjacent to the gallbladder that was initially interpreted radiologically as a probable gallbladder diverticulum. The patient subsequently underwent laparoscopic cholecystectomy. Gross examination demonstrated a 3.5 cm subserosal cystic lesion within the gallbladder wall. Histologic evaluation revealed a cyst lined by pseudostratified ciliated columnar (respiratory-type) epithelium with mucinous differentiation, consistent with a ciliated foregut cyst. No dysplasia or malignancy was identified. The patient's postoperative course was uncomplicated. Ciliated foregut cysts of the gallbladder may mimic gallbladder diverticula or other cystic lesions on imaging, making preoperative diagnosis challenging. The cyst in the present case measured 3.5 cm and represents one of the largest reported ciliated foregut cysts of the gallbladder in the literature. This case highlights the importance of histopathologic evaluation and the need to consider a ciliated foregut cyst in the differential diagnosis of cystic lesions associated with the gallbladder.