Mucoepidermoid carcinoma explained

Mucoepidermoid carcinoma
Field:Oncology, Maxillofacial surgery, ENT surgery

Mucoepidermoid carcinoma (MEC)[1] is the most common type of minor salivary gland malignancy in adults. Mucoepidermoid carcinoma can also be found in other organs, such as bronchi, lacrimal sac,[2] and thyroid gland.

Mucicarmine staining is one stain used by pathologist for detection.[3]

Signs and symptoms

Presents as painless, slow-growing mass that is firm or hard. Most appear clinically as mixed tumors. Usually occurs at 30–50 years of age. More predilection towards female sex.

Diagnosis

Histology

This tumor is not encapsulated and is characterized by squamous cells, mucus-secreting cells, and intermediate cells.[4]

Molecular biology

Mucoepidermoid carcinomas of the salivary and bronchial glands are characterized by a recurrent t(11;19)(q21;p13) chromosomal translocation resulting in a MECT1-MAML2 fusion gene.[5] The CREB-binding domain of the CREB coactivator MECT1 (also known as CRTC1, TORC1 or WAMTP1) is fused to the transactivation domain of the Notch coactivator MAML2.[6]

A possible association with Radiation Exposure has been reported.[7] It has also been proposed that mucoepidermoid tumors arise from subepithelial mucus glands of the upper respiratory or digestive tracts.[8]

Prognosis

Generally, there is a good prognosis for low-grade tumors, and a poor prognosis for high-grade tumors, however recent research have found reoccurring low grade tumors also have a poor prognosis.[9]

Treatment

Surgery is the recommended treatment for localised resectable disease.[10] When the tumour is incompletely resected (positive margins) post-operative radiotherapy gives local control comparable to a complete resection (clear margins).[11]

Sometimes when surgery is not possible due to extent of disease or if a patient is too frail for surgery, or declines surgery, palliative radiotherapy may be helpful. There has been a report of a case where low dose radiotherapy achieve disease response and control for more than 4 years.[12]

In patients with metastatic disease, chemotherapy response tends to be low (27% partial response rate) and short lived.[13]

Epidemiology

Occurs in adults, with peak incidence from 20–40 years of age. A causal link with cytomegalovirus (CMV) has been strongly implicated in a 2011 research.[14]

Notes and References

  1. Kalhor N, Moran CA . Pulmonary mucoepidermoid carcinoma: diagnosis and treatment . Expert Review of Respiratory Medicine . 12 . 3 . 249–255 . March 2018 . 29338644 . 10.1080/17476348.2018.1428563 . 46808485 .
  2. Williams JD, Agrawal A, Wakely PE . Mucoepidermoid carcinoma of the lacrimal sac . Annals of Diagnostic Pathology . 7 . 1 . 31–34 . February 2003 . 12616472 . 10.1053/adpa.2003.50005 .
  3. Baloch ZW, Solomon AC, LiVolsi VA . Primary mucoepidermoid carcinoma and sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid gland: a report of nine cases . Modern Pathology . 13 . 7 . 802–807 . July 2000 . 10912941 . 10.1038/modpathol.3880140 . free .
  4. Chenevert J, Barnes LE, Chiosea SI . Mucoepidermoid carcinoma: a five-decade journey . Virchows Archiv . 458 . 2 . 133–140 . February 2011 . 21243374 . 10.1007/s00428-011-1040-y . 19767354 .
  5. Chiosea SI, Dacic S, Nikiforova MN, Seethala RR . Prospective testing of mucoepidermoid carcinoma for the MAML2 translocation: clinical implications . The Laryngoscope . 122 . 8 . 1690–1694 . August 2012 . 22833306 . 10.1002/lary.22419 . 33158886 .
  6. Behboudi A, Enlund F, Winnes M, Andrén Y, Nordkvist A, Leivo I, Flaberg E, Szekely L, Mäkitie A, Grenman R, Mark J, Stenman G . 6 . Molecular classification of mucoepidermoid carcinomas-prognostic significance of the MECT1-MAML2 fusion oncogene . Genes, Chromosomes & Cancer . 45 . 5 . 470–481 . May 2006 . 16444749 . 10.1002/gcc.20306 . 37146319 .
  7. Web site: Rare Mucoepidermoid Carcinoma . Oral Cancer Foundation.
  8. Web site: Mucoepidermoid Carcinoma Causes . Medical News Today.
  9. Rubin A, Davis J, Jreije K, Wu H, Oppenheimer R . Case Report: Recurrent Mucoepidermoid Carcinoma of the Tongue in Adult Female Patient With Lung Cancer . Clinical Medicine Insights. Ear, Nose and Throat . 10 . 1179550617720462 . 2017 . 28757800 . 5513522 . 10.1177/1179550617720462 .
  10. Verma J, Teh BS, Paulino AC . Characteristics and outcome of radiation and chemotherapy-related mucoepidermoid carcinoma of the salivary glands . Pediatric Blood & Cancer . 57 . 7 . 1137–1141 . December 2011 . 21280198 . 10.1002/pbc.22978 . 147761 .
  11. Hosokawa Y, Shirato H, Kagei K, Hashimoto S, Nishioka T, Tei K, Ono M, Ohmori K, Kaneko M, Miyasaka K, Nakamura M . 6 . Role of radiotherapy for mucoepidermoid carcinoma of salivary gland . Oral Oncology . 35 . 1 . 105–111 . January 1999 . 10211318 . 10.1016/s1368-8375(98)00053-0 .
  12. Vulpe H, Giuliani M, Goldstein D, Perez-Ordonez B, Dawson LA, Hope A . Long term control of a maxillary sinus mucoepidermoid carcinoma with low dose radiation therapy: a case report . Radiation Oncology . 8 . 251 . October 2013 . 24165756 . 3829377 . 10.1186/1748-717X-8-251 . free .
  13. Licitra L, Cavina R, Grandi C, Palma SD, Guzzo M, Demicheli R, Molinari R . Cisplatin, doxorubicin and cyclophosphamide in advanced salivary gland carcinoma. A phase II trial of 22 patients . Annals of Oncology . 7 . 6 . 640–642 . August 1996 . 8879381 . 10.1093/oxfordjournals.annonc.a010684 . free .
  14. Melnick M, Sedghizadeh PP, Allen CM, Jaskoll T . Human cytomegalovirus and mucoepidermoid carcinoma of salivary glands: cell-specific localization of active viral and oncogenic signaling proteins is confirmatory of a causal relationship . Experimental and Molecular Pathology . 92 . 1 . 118–125 . February 2012 . 22101257 . 10.1016/j.yexmp.2011.10.011 . 41446671 .