muscularis mucosae


Also found in: Dictionary, Medical, Wikipedia.
Related to muscularis mucosae: submucosa, submucosal plexus, Muscularis externa

muscularis mucosae

[‚məs·kyə′lar·əs myü′kō·sē]
(histology)
Thin, deep layer of smooth muscle in some mucous membranes, as in the digestive tract.
References in periodicals archive ?
Figure 3C showed that the labeled cells were both negative in the lamina muscularis mucosae and muscular layer.
The location of the staining (lamina propria, muscularis mucosae, and submucosa) was also registered (Table 1).
The lymphoid follicles and aggregates were categorized in 3 groups: (1) sub-epithelial small, present just below the epithelium and occupying half or less of the lamina propria; (2) basal small, present just above the muscularis mucosae and occupying half or less of the lamina propria; and (3) large, occupying more than half the thickness of the lamina propria.
Second, many cycles of reflux injury cause duplication of the muscularis mucosae; in most patients with BE, the original muscularis mucosae is present, but a second, more delicate smooth muscle layer is found closer to the surface (Figure 17).
Any proliferation of neoplastic epithelium beyond the muscularis mucosae is at risk for peritoneal dissemination and should be graded and staged as a carcinoma, as described in the World Health Organization classification and staging guidelines put forth by the American Joint Committee on Cancer.
Colonic polypoid leiomyomas are circumscribed, nodular proliferations of smooth cells that are in continuity with the fibers of the muscularis mucosae, suggesting that they arise from there.
Most leiomyosarcomas also present as intraluminal polypoid tumors, although origin specifically from the muscularis mucosae could not be documented in any of the 8 leiomyosarcomas of the rectum and anus studied by Miettinen et al.
The mild nuclear atypia, presence of signet ring-like tubules, infiltrating pattern into the deep lamina propria, including focal involvement of muscularis mucosae and superficial muscularis propria, were unusual and prompted an immunohistochemical workup to rule out malignancy.
Intramucosal carcinoma is defined as a neoplasm that has invaded into the surrounding lamina propria or muscularis mucosae but not into the submucosa (Figure 5).
For accurate histopathologic assessment of villus to crypt ratio, it is essential that the biopsy specimen be properly oriented with the luminal surface upwards such that the villi should be vertical to the muscularis mucosae (Figure 2).
Although some pathologists require destructive invasion of the appendix with infiltrating glands to make the diagnosis of adenocarcinoma, others argue that mucinous tumors in the appendix invade along a broad front characterized by neoplastic epithelium directly abutting the hyalinized cyst wall with obliteration of the muscularis mucosae (Figure 5).
Elastosis (diffuse or focal increase in elastic fibers in the submucosal and muscularis mucosae layers of the gut) and elastofibromatous change (if there is an accompanying increase in fibrous tissue) are harmless abnormalities that can occasionally develop in the alimentary tract and may form polypoid lesions.