大城 久

INTRODUCTION: Spontaneous tumor regression (STR) is a rare phenomenon in which cancer cells partially or completely disappear without treatment. We report a case of intrahepatic cholangiocarcinoma demonstrating STR following endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA). CASE PRESENTATION: A 77-year-old male presented with acute cholecystitis 1 day after percutaneous coronary intervention for acute myocardial infarction. Conservative treatment and endoscopic retrograde gallbladder drainage were performed due to antiplatelet therapy. Cytology of bile juice unexpectedly revealed adenocarcinoma. Further imaging, including CT and mapping biopsy, failed to detect a tumor. Laparoscopic cholecystectomy with gallbladder bed resection showed no histological evidence of malignancy. Four months later, surveillance CT revealed a 15 × 15 mm lesion in segment 3 of the liver. EUS-FNA confirmed adenocarcinoma. Laparoscopic left lateral resection was performed; however, no viable cancer cells were identified, and the lesion was replaced by epithelioid granulomas. Immunohistochemistry demonstrated dense infiltration of CD8-positive cytotoxic T cells, suggesting an immune-mediated regression of the tumor. CONCLUSIONS: This case highlights the possibility of tumor regression in intrahepatic adenocarcinoma following EUS-FNA, potentially triggered by an immune response.

Cutaneous arteritis (CA) is a rare cutaneous manifestation of Crohn's disease. A 50-year-old woman with a 15-year history of CA was admitted to our hospital with a fever, abdominal pain, and hematochezia. Based on these symptoms and increased C-reactive protein levels, systemic vasculitis was considered. However, emergency colonoscopy revealed multiple longitudinal ulcers throughout the colon, thus suggesting Crohn's disease. Prednisolone (60 mg/day) was administered intravenously. A histopathological examination of the biopsied colonic mucosa revealed epithelioid granulomas, which confirmed the diagnosis of Crohn's disease. Because the systemic evolution of CA is rare, other comorbidities should be considered when patients with CA experience systemic manifestations.