Benign Gallbladder Tumors

Benign gallbladder tumors were rare historically; with imaging (especially ultrasound) detection has risen (4.5-8.6% of cholecystectomies). Nomenclature confusing: historically 'papilloma'/'polyp'; Japanese 'elevated lesions'; Chinese 'polypoid lesion of gallbladder (PLG)'. Imperfect: Japanese elevated lesions include gallbladder cancer; benign tumors aren't all polypoid. These are morphologic/radiologic diagnostic terms.

Common Symptoms

Abdominal tenderness; anorexia; thinned gallbladder wall; nausea; dyspepsia

Causes and Pathogenesis

(1) Etiology: unknown. Gallbladder polyps = papillary adenomas; cholesterol vs inflammatory. Cholesterol: high gallbladder pressure/cholesterol metabolism disorder → cholesterol crystals in basal epithelium/macrophage accumulation. Inflammatory: chronic inflammation → glandular epithelial hyperplasia + lymphocyte/monocyte infiltrate. Adenomyoma: mucosal hyperplasia/hypertrophy; increased Rokitansky-Aschoff sinuses extending into muscle, communicating with lumen → pseudodiverticula. (2) Mechanism: (a) Benign tumors. Adenoma: mucosal epithelial origin, 23% of benign gallbladder lesions, 1% of cholecystectomies; female predominance; solitary; any site; brown-red; 5.5±3.1mm (1-25mm), most <10mm. Subtypes: papillary (pedunculated/sessile; branching fibrovascular core; single-layer cuboidal/columnar epithelium); non-papillary (tubular adenoma; pedunculated; glands in stroma; occasional goblet-cell/intestinal metaplasia). Cancer risk: debated; 11.3% malignant rate; sessile 33% > pedunculated 13%; size cutoff 12mm (Kozuka: benign 5.5mm vs malignant 17.6mm; >10mm = surgery; 94% benign <10mm, 88% malignant >10mm; but some <10mm already malignant). Histologic progression: stroma thins, glands crowd, nuclei enlarge, pseudostratification. 19% of invasive cancers have residual adenoma. Risk factors: older age, female, gallstones. Support-tissue tumors: hemangioma/lipoma/leiomyoma/granular-cell tumor (rare; 20+ reported GCT cases; mostly in cystic duct; neurogenic, PAS-positive granules; no malignant change reported). (b) Pseudotumors (non-neoplastic): polyps, hyperplastic lesions, ectopia. Gallbladder polyps = 67% of benign lesions; cholesterol polyps (67%: yellow lobulated/mulberry, soft, pedunculated, 3-5mm, <10mm, foam macrophages, strawberry gallbladder; no malignant potential); inflammatory polyps (3-5mm, rough pedicle, associated with chronic cholecystitis/gallstones; no malignant change). Hyperplastic lesions: adenomyomatous hyperplasia (localized/segmental/diffuse; fundus; 5-25mm nodule with central umbilication; Rokitansky-Aschoff sinuses; Christensen says no malignant potential, but Paraf reported 2 cancers; Muto: >5 RAS/cm wall thickening >3mm); adenomatous hyperplasia (villous/spongy type); ectopia (gastric/small-intestinal/pancreatic/hepatic/thyroid mucosa near neck/cystic duct; 10-25mm); other (parasitic granuloma/traumatic neuroma/suture granuloma).

Treatment

Surgery, drug, supportive therapy

Preventive Measures

(1) Positive mood; diet; avoid spicy/greasy/spirits. (2) >40y (especially women): regular ultrasound; follow cholecystitis/gallstones/polyps.

Department to Visit

It is recommended to visit the Hepatobiliary Surgery department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.