Mucoepidermoid carcinoma pathophysiology
Mucoepidermoid carcinoma Microchapters
Mucoepidermoid carcinoma pathophysiology On the Web
American Roentgen Ray Society Images of Mucoepidermoid carcinoma pathophysiology
Mucoepidermoid carcinomas arise from mucous cells, which are normally involved in the secretion of mucous and the protection of the surrounding tissue. The pathogenesis of mucoepidermoid carcinoma consists of abnormal production of mucin from mucous cells, associated with the aberrant overgrowth of squamous and epidermoid cells. Genes involved in the pathogenesis of mucoepidermoid carcinoma include the MECT1 and MAML2 fusion genes. On gross pathology, mucoepidermoid carcinomas have a cystic, solid or mixed appearance, are normally located on the parotid or submandibular gland, and range in size from 1 to 8 cm.
- Mucoepidermoid carcinoma originates from pluripotent cells of the excretory ducts of glandular structures.
- The tumor primarily comprises of mucous, intermediate and epidermoid cells.
- Mucous cells, which are normally involved in the secretion of mucous and protection of the surrounding tissue.
- The pathogenesis of mucoepidermoid carcinoma consists of abnormal production of mucin from mucous cells, associated with the aberrant overgrowth of squamous and epidermoid cells.
- Development of mucoepidermoid carcinoma may be the result of multiple genetic mutations.
- Mucoepidermoid carcinoma is specifically associated with t(11;19)(q21;p13) translocation.
- CRTC1-MAML2 fusion is a primary driver for mucoepidermoid carcinoma initiation and maintenance.
- This translocation creates a MECT1-MAML2 fusion protein that disrupts the Notch signaling pathway.
- This fusion protein is expressed by all cell types of mucoepidermoid when the translocation is present.
- Genes involved in the pathogenesis of include:
- The CRTC1-MAML2 fusion protein induces the upregulation of the epidermal growth factor receptor (EGFR) ligand Amphiregulin (AREG) by co-activating the transcription factor CREB.
- AREG subsequently activates EGFR signaling in an autocrine manner that promotes mucoepidermoid carcinoma cell growth and survival.
- Aberrantly activated AREG-EGFR signaling is essential for CRTC1-MAML2positive mucoepidermoid carcinoma cell growth and survival.
- As HCMV is commonly resides in salivary gland ductal epithelium, It is hypothesized that HCMV could be integral part of pathogenesis of mucopidermoid carcinoma.
- Following results were noted when they tested implication of HCMV in development
- On gross pathology, mucoepidermoid carcinoma has a cystic, solid, or mixed appearance.
- Mucoepidermoid carcinoma usually occurs in the parotid or submandibular gland.
- Low grade mucoepidermoid carcinoma are small and partially encapsulated.
- It appears as fluctuant light blue or purplish submucosal lumps. 
- Other findings on gross pathology include:
- Mucin vacuoles may be rare; however they are integral part of histological features of mucoepidermoid carcinoma.
- Hallmark of these tumors are:
- Mucoepidermoid tumors are graded histologically into:
- Low grade
- Intermediate grade
- High grade.
- Low grade is characterized by well-differentiated cells with little cellular atypia, high proportion of mucous cells, and prominent cyst formation.
- Intermediate grade is characterized by intermediate features
- High grade is characterized by poorly differentiated with cellular pleomorphism, high proportion of squamous cells, and solid with few if any cysts
Histopathologic image of mucoepidermoid carcinoma of the major salivary gland. H & E stain.
Histopathologic image of mucoepidermoid carcinoma of the major salivary gland.
Histopathologic image of mucoepidermoid carcinoma. Postoperative recurrence of the submandibular tumor. Alcian blue-PAS stain.
Gross pathology mucoepidermoid carcinoma.
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- Mucoepidermoid carcincoma Libre Pathology. http://librepathology.org/wiki/index.php/Mucoepidermoid carcincoma Accessed on February 17, 2015