Mucoepidermoid carcinoma is the most common type of salivary gland

Salivary gland

The salivary glands in mammals are exocrine glands, glands with ducts, that produce saliva. They also secrete amylase, an enzyme that breaks down starch into maltose...

 malignancy in children. Mucoepidermoid carcinoma can also be found in other organs, as bronchi, lacrimal sac and thyroid.

Mucicarmine staining is one stain used by pathologist for detection.

Epidemiology

Occurs in adults, with peak incidence from 20–40 years of age. A causal link with cytomegalovirus

Cytomegalovirus

Cytomegalovirus is a viral genus of the viral group known as Herpesviridae or herpesviruses. It is typically abbreviated as CMV: The species that infects humans is commonly known as human CMV or human herpesvirus-5 , and is the most studied of all cytomegaloviruses...

 (CMV) has been strongly implicated in a 2011 research.

Clinical Features

Presents as painless, slow-growing mass that is firm or hard. Most appear clinically as mixed tumors.

Histology

This tumor is not encapsulated and is characterized by squamous cells, mucus-secreting cells, and intermediate cells.

Molecular biology

Mucoepidermoid carcinomas of the salivary and bronchial glands are characterized by a recurrent t(11;19)(q21;p13) chromosomal translocation

Chromosomal translocation

In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise separated genes, the occurrence of which is common in cancer. It is detected on...

 resulting in a MECT1-MAML2 fusion gene

Fusion gene

A fusion gene is a hybrid gene formed from two previously separate genes. It can occur as the result of a translocation, interstitial deletion, or chromosomal inversion...

. The CREB-binding domain of the CREB

CREB

CREB is a cellular transcription factor. It binds to certain DNA sequences called cAMP response elements , thereby increasing or decreasing the transcription of the downstream genes....

 coactivator MECT1 (also known as CRTC1, TORC1 or WAMTP1) is fused to the transactivation domain of the Notch coactivator MAML2

MAML2

Mastermind-like protein 2 is a protein that in humans is encoded by the MAML2 gene.Details on the activity of the N-terminal domain of Mastermind-like protein 2may be found under MamL-1.-Further reading:...

(PMID:16444749).

Prognosis

Generally, there is a good prognosis for low-grade tumors, and a poor prognosis for high-grade tumors.

External links

• Overview at usc.edu
• Slide at jhu.edu
• mucoepidermoid carcinoma at humpath.com
• salivary mucoepidermoid carcinoma images at humpath.com