Gastric polyps are proliferative growths found in the stomach, not the gallbladder. Gallbladder polyps, on the other hand, are growths located in the gallbladder. During ultrasound examinations, gallbladder polyps are detected in approximately 1.5% to 4.5% of cases, with the detection rate increasing to as high as 13.8% in surgically removed gallbladders. Although gallbladder polyps are rare in children, they can occur either in isolation or in association with conditions such as Peutz-Jeghers syndrome or abnormal pancreaticobiliary duct union. Gallbladder polyps may be benign (non-cancerous) or malignant (cancerous), with benign polyps further classified into neoplastic (tumor-forming) and non-neoplastic (non-tumor-forming) types.
Types of Benign Polyps
Cholesterol polyps and cholesterol deposits: Cholesterol deposits are accumulations of fat within the gallbladder wall. These deposits can be diffuse, spreading throughout the gallbladder, or polypoid, forming polyps. Diffuse cholesterol deposits are often discovered incidentally during gallbladder removal surgery. Cholesterol polyps are the most common type and are usually found incidentally during ultrasound examinations. Although they typically do not cause symptoms, they can sometimes lead to complications similar to those caused by gallstones.
Inflammatory polyps are the rarest type, appearing on ultrasound as either flat (sessile) or stalked (pedunculated) lesions. They consist of granulation tissue, fibrous tissue, and immune cells, typically measuring 5 to 10 millimeters, although larger polyps have also been reported.
Adenomyomatosis involves the proliferation of the gallbladder mucosa, thickening of the muscular wall, and the formation of intramural cystic structures. Although rare, it is more common in women. In one study of over 10,000 gallbladder surgeries, only 1% of cases exhibited this condition.
Neoplastic Polyps
Adenomas are the most common benign tumors of the gallbladder, with an incidence of less than 0.5%. They are classified as papillary (finger-like) or non-papillary, similar to intestinal polyps. These polyps carry a significant risk of malignant transformation, particularly when their size reaches 10 millimeters or more.
Malignant Polyps
Adenocarcinoma is the most common malignant gallbladder polyp. Unlike benign tumors in the intestine, malignant proliferations are more frequently observed in the gallbladder. Rare types of gallbladder cancer include squamous cell carcinoma, mucinous cystadenocarcinoma, and adenosquamous carcinoma.
Understanding the different types of gallbladder polyps and their characteristics can aid in early detection and treatment, leading to improved health outcomes. If you have concerns about gallbladder polyps, please consult your healthcare provider for personalized advice and screening options.