Talk:Gastrointestinal Tract - Gall Bladder Histology

Gall Bladder

Anatomy

Pear-shaped
distensible sac (about 50ml volume)
Attached to posterioinferior surface of liver
Embryonic - foregut, forms from primitive bile duct
leads to cystic duct
- Liver -> hepatic duct
- Gall bladder -> cystic duct
- Common Bile duct

Function

enteroendocrine cells respond to fat in duodenum
contract smooth muscle

Histology

Epithelium

mucosal folds
mucosal sinuses (Rokintansky-Aschoff sinuses)
simple columnar epithelium (no mucus-producing cells, except in neck region)
apical microvilli
basal nucleus
basement membrane (not basal lamina and EM structure)

Lamina Propria

rich in blood vessels (capillaries, venules, no lymphatics?)

2010

Muscularis mucosae versus muscularis propria in gallbladder, cystic duct, and common bile duct: smoothelin and desmin immunohistochemical study

Ann Diagn Pathol. 2010 Dec;14(6):408-12. Epub 2010 Sep 22.

Raparia K, Zhai QJ, Schwartz MR, Shen SS, Ayala AG, Ro JY. Source Department of Pathology, The Methodist Hospital, Weill Medical College, Cornell University, Houston, TX 77030, USA.

Abstract

The muscle layer in the cystic duct and common bile duct is not well defined, and it is unresolved whether it represents muscularis mucosae or muscularis propria. Smoothelin is a novel smooth muscle-specific contractile protein expressed only in fully differentiated smooth muscle cells of the muscularis propria and not in proliferative or noncontractile smooth muscle cells of the muscularis mucosae. In this study, we characterize the histologic aspects of the muscle layer in gallbladder, cystic duct, and common bile duct by evaluation of routine histologic sections and the utilization of immunohistochemistry using desmin and smoothelin. Formalin-fixed, paraffin-embedded sections of the gallbladder (15 cases), cystic duct (11 cases), and common bile duct (10 cases) were stained for smoothelin and desmin. Staining intensity was evaluated as weak or strong. The staining pattern score was evaluated as follows: 0 or negative = less than or equal to 5% positivity, +1 or focal = 6% to 10% positivity, +2 or moderate = 11% to 50% positivity, and +3 = greater than 50% muscle cells positivity. With desmin, strong and diffuse (+3) staining was observed in all gallbladder cases (15/15, 100%), highlighting one continuous muscle layer. The muscle layer was discontinuous and interrupted in all cystic duct cases and in most common bile ducts, highlighted by the desmin stain. Smoothelin intensely stained (at least +2) muscle fibers in the gallbladder in 11 (73%) of 15 cases similar to that observed with desmin staining. In contrast, common bile ducts predominantly had absent or weak and focal immunostaining (0 or +1 staining) with smoothelin (7/10, 70%), with only a few cases (3/10, 30%) having +2 staining (no cases with +3). Cystic ducts also showed absent or weak and focal immunostaining with smoothelin, with 5 (44%) of 11 cases showing 2+ immunostaining with smoothelin (no cases with 3+). Based on our findings, we conclude that, in the gallbladder wall, the muscle layer is muscularis propria and there is no muscularis mucosae present. In the cystic duct and common bile duct, only an attenuated and incomplete muscle layer of muscularis mucosae is present; because there is no muscularis propria, there probably is limited contractile function. Differentiating these anatomical muscle structures may be important for the pathologic staging of carcinoma in these organs.

PMID 21074688

Rokitansky-Aschoff sinuses of the gallbladder are associated with black pigment gallstone formation: a scanning electron microscopy study

Ultrastruct Pathol. 2003 Jul-Aug;27(4):265-70.

Cariati A, Cetta F. Source Emergency Surgery Department, Villa Scassi Hospital, Genoa, Italy. andrea.cariati@villascassi.it

Abstract

Rokitansky-Aschoff sinuses are the result of hyperplasia and herniation of epithelial cells through the fibromuscular layer of the gallbladder wall and are usually referred to as adenomyomatosis. The role of this study is to demonstrate that Rokitansky-Aschoff sinuses of the gallbladder are a risk factor for the formation of black pigment gallstones. A total of 179 removed gallbladders, were hystologically examined. Sixty-four of the 179 consecutive cholecystomized patients had typical adenomyomatosis. Thirty-eight of the 64 patients with adenomyomatosis had black pigment gallstones, alone (n=22) or in association with single (n=12) or multiple (n=4) cholesterol gallstones in the same gallbladder. Twelve of these patients did not have the typical risk factors for black stones (hemolysis, cirrhoses, gastrectomy, etc). Gallstones were examined by infrared spectroscopy and X-ray diffractometry. In addition, in a subset of 14 patients, the gallstones and the gallbladder wall were examined by scanning electron microscopy. At least in the initial phases of formation, Rokitansky-Aschoff sinuses were found close to small intraparietal vessels and sometimes they contained black pigment microstones. After the fourth to fifth decades of life, black gallstones can be found in the Rokitansky-Aschoff sinuses and in the main gallbladder lumen. Black pigment gallstones can form in Rokitansky-Aschoff sinuses of the gallbladder in absence of the typical risk factors for bilirubin suprasaturation of bile. PMID 12907372