Preoperative Diagnosis of Intracholecystic Papillary Neoplasm Based on Characteristic Preoperative Images: A Case Report

A 79-year-old woman underwent chest CT for follow-up of a nodular shadow in the lungs. The scan revealed a mass lesion in the gallbladder and she was referred to our department for further examination and treatment. The fundus of the gallbladder had a progressively contrasted tumor measuring more than 5 cm. Calcification was observed in the center of the stem. The tumor produced mucus with no peritumoral invasion. Thus, it was diagnosed as intracholecystic papillary neoplasm (ICPN), and extended cholecystectomy and sentinel lymphadenectomy were performed. Gross findings of the resected specimen showed a white papillary lesion with mucus accumulation and necrotic areas in the gallbladder cavity. Histopathological examination revealed ICPN with a mixture of low- and high-grade dysplasia and invasive carcinoma in a small area. Histologic subclassification led to diagnosis as a gastric type based on gross findings and MUC staining. Because of the micrometastasis in the #12c lymph node proved by pathological examinations, D2 lymph node dissection was added after the initial surgery.