A 66-year-old woman with no significant past medical history presents with a 3-day history of right upper quadrant pain. She is referred by her primary medical doctor. Physical examination reveals no jaundice, anemia, lymphadenopathy, or specific abdominal findings.

There are a variety of tumors or tumor-like lesions arising in the gallbladder, which often present as protruded (polypoid) lesions. Epithelial tumors include carcinoma, dysplasia, and adenoma, whereas tumor-like lesions comprise hyperplasia, adenomyomatosis, polyps, and others. Among protruded lesions of the gallbladder, the cholesterol polyp is the most common. Once protruded lesions are detected on imaging, the discrimination between benign and malignant is clinically important, and it mainly depends on the size of the lesion. Most protruded lesions smaller than 1 cm in maximum diameter are benign. In contrast, many cancers appear as large polypoid lesions, and those exceeding 1.5 cm in maximum diameter are very likely to be malignant. The shape of the lesion is another useful hint when discriminating benign from malignant lesions. Carcinoma is usually sessile (with the exception of carcinoma in pedunculated adenoma), while most benign lesions are pedunculated.

In this patient, with a sessile protruded lesion far exceeding 1.5 cm in the gallbladder, one must consider gallbladder carcinoma as the primary diagnosis. The irregular (granular) contour of the lesion on cholangiography (Fig. 46.2) also supports this diagnosis.

Gallbladder carcinoma. A computed tomography (CT) scan of the abdomen is recommended for staging of the tumor.