Editing Gallbladder polyps

Outgrowths of the gallbladder mucosal wall

== '''Pathophysiology''' ==

* See separate topic of 'gallbladder cancer' - suspected adenoma-carcinoma sequence involving polyps
* The only polypoid lesions that have malignant potential are adenomatous polyps

== '''Classification''' ==

=== '''Benign''' ===

** '''Cholesterolosis/cholesterol polyps'''
*** Accumulation of lipids in the mucosa of the gallbladder wall
*** Diffuse (cholesterolosis) or polypoid (cholesterol polyp) type
**** Diffuse type is usually diagnosed incidentally during cholecystectomy (9-26%)
**** Cholesterol polyp is the most common form of GB polyp
*** Results from abnormal deposits of triglycerides, cholesterol precursors, and cholesterol esters in the GB mucosa. The lipid accumulation creates yellow deposits which are visible macroscopically.
*** Polyps can form from cholesterol and lipid-filled macrophages, which can theoretically break off and cause symptoms akin to gallstones
*** Also called 'strawberry gallbladder' due to appearance of pits
** '''Inflammatory'''
*** Uncommon
*** Appear as granulation and fibrous tissue
*** Usually <1cm
** '''Adenomyomatosis'''
*** Hyperplasia of the mucosa and muscularis propria
*** Pathognomic epithelial invaginations forming cystic pockets (Rokitansky-Aschoff sinuses) which may contain calculi or cholesterol crystals
*** Can be diffuse, segmental or localised to the fundus of the gallbladder
*** Possibly secondary to chronic inflammation
*** Seen on USS as echogenic foci with comet tail artefacts

=== '''Neoplastic''' ===

** '''Adenoma'''
*** Benign epithelial tumours composed of cells resembling biliary tract epithelium
*** Increasing risk of cancer with increasing polyp size
** Fibroma
** Lipoma
** Leiomyoma

=== '''Malignant''' ===

== '''Predictors of malignancy''' ==

* Single polyp
* Sessile polyp
* Size >10mm
** Risk of malignancy 43-77%
** 128.2 GB cancers per 100,000 person-years
** 1.3 per 100,000 person-years for polyps <6mm
* Age >60yo
* PSC
** About half of polyps will have malignancy
* Indian ethnicity

== '''Complications''' ==

* Risk of progression to cancer
* Unclear association with cholecystitis
* Cholecystitis seems to occur more commonly in patients with stones and polyps vs those with just stones

== '''Indications for surgery''' ==

* Polyps > 1cm
* Radiographic evidence of vascular stalks
* Lower threshold for surgery in the setting of other prominent risk factors such as PSC

== '''Non-operative management''' ==

* Surveillance of polyps not meeting resectability criteria
* Polyps 6-9mm without risk factors for malignancy:
** USS at 6 months and 12 months
** Then annual USS thereafter if stable
* Polyps <6mm
** Repeat USS at least once, 12 months later, and then for consideration of further surveillance
** However very low chance of harbouring malignancy if size is stable

[[Category:Biliary]]