It is the third-most common malignant salivary gland tumor overall (after mucoepidermoid carcinoma and polymorphous adenocarcinoma). It represents 28% of malignant submandibular gland tumors, making it the single most common malignant salivary gland tumor in this region. Patients may survive for years with metastases because this tumor is generally well-differentiated and slow growing. In a 1999 study[3] of a cohort of 160 ACC patients, disease-specific survival was 89% at 5 years, but only 40% at 15 years,[citation needed] reflecting deaths from late-occurring metastatic disease.
Activation of the oncogenic transcription factor gene MYB is the key genomic event of ACC and seen in the vast majority of cases.[4][5]
Most commonly, MYB is activated through gene fusion with the transcription factor encoding NFIB gene as a result of a t(6;9) translocation.[4] Alternatively, MYB is activated by copy number gain or by juxtaposition of enhancer elements in the vicinity of the MYB gene.[6]
In a subset of ACCs, the closely related MYBL1 gene is fused to NFIB or to other fusion partners.[7][8]
MYB drives proliferation of ACC cells and regulates genes involved in cell cycle control, DNA replication and repair, and RNA processing.[9] Thus, the MYB oncogene is a potential diagnostic and therapeutic target in ACC.
ACC has a relatively quiet genome with few recurrent copy number alterations or point mutations,[6][10][11][12] consistent with the view that MYB and MYBL1 are the main oncogenic drivers of the disease.
Primary treatment for this cancer, regardless of body site, is surgical removal with clean margins. This surgery can prove challenging in the head and neck region due to this tumor's tendency to show a perineural discontinuous growth, meaning that it follows nerves and different "nests" of the tumor can exist without a connection to the original tumor. Therefore, MRI-images should be analysed following nerve tracts up to the brainstem. Adjuvantorpalliativeradiotherapy is commonly given following surgery. For advanced major and minor salivary gland tumors that are inoperable, recurrent, or exhibit gross residual disease after surgery, fast neutron therapy is widely regarded as the most effective form of treatment.[13][14][15][16]Chemotherapy is used for metastatic disease. Chemotherapy is considered on a case-by-case basis, as data on the positive effects of chemotherapy are limited. Clinical studies are ongoing, however.[citation needed]
Coronal MRI showing right parotid adenoid cystic carcinoma with perineural spread of tumor: The tumor originates in the right parotid gland and spreads along the trigeminal nerve via the auricuotemporal branch extending intracranially through the foramen ovale at the skull base towards Meckel's cave.
Coronal MRI showing right parotid adenoid cystic carcinoma with perineural spread of tumor along the facial nerve extending to the stylomastoid foramen
Histopathological image of adenoid cystic carcinoma of the salivary gland infiltrating a nerve (center), H&E stain
Histopathological image of adenoid cystic carcinoma of the salivary gland, immunostain for S-100 protein
^Andersson MK, Stenman G (2016). "The landscape of gene fusions and somatic mutations in salivary gland neoplasms - Implications for diagnosis and therapy". Oral Oncol. 57: 63–9. doi:10.1016/j.oraloncology.2016.04.002. PMID27101980.
^ abPersson M, Andrén Y, Moskaluk CA, Frierson HF Jr, Cooke SL, Futreal PA, Kling T, Nelander S, Nordkvist A, Persson F, Stenman G (2012). "Clinically significant copy number alterations and complex rearrangements of MYB and NFIB in head and neck adenoid cystic carcinoma". Genes Chromosomes Cancer. 51 (8): 805–17. doi:10.1002/gcc.21965. PMID22505352. S2CID25742114.
^Ho AS, Kannan K, Roy DM, Morris LG, Ganly I, Katabi N, Ramaswami D, Walsh LA, Eng S, Huse JT, Zhang J, Dolgalev I, Huberman K, Heguy A, Viale A, Drobnjak M, Leversha MA, Rice CE, Singh B, Iyer NG, Leemans CR, Bloemena E, Ferris RL, Seethala RR, Gross BE, Liang Y, Sinha R, Peng L, Raphael BJ, Turcan S, Gong Y, Schultz N, Kim S, Chiosea S, Shah JP, Sander C, Lee W, Chan TA (2013). "The mutational landscape of adenoid cystic carcinoma". Nat Genet. 45 (7): 791–8. doi:10.1038/ng.2643. PMC3708595. PMID23685749.
^Stephens PJ, Davies HR, Mitani Y, Van Loo P, Shlien A, Tarpey PS, Papaemmanuil E, Cheverton A, Bignell GR, Butler AP, Gamble J, Gamble S, Hardy C, Hinton J, Jia M, Jayakumar A, Jones D, Latimer C, McLaren S, McBride DJ, Menzies A, Mudie L, Maddison M, Raine K, Nik-Zainal S, O'Meara S, Teague JW, Varela I, Wedge DC, Whitmore I, Lippman SM, McDermott U, Stratton MR, Campbell PJ, El-Naggar AK, Futreal PA (2013). "Whole exome sequencing of adenoid cystic carcinoma". J Clin Invest. 123 (7): 2965–8. doi:10.1172/JCI67201. PMC3999050. PMID23778141.
^Laramore, GE (September 1987). "Fast neutron radiotherapy for inoperable salivary gland tumors: is it the treatment of choice?". International Journal of Radiation Oncology, Biology, Physics. 13 (9): 1421–3. doi:10.1016/0360-3016(87)90240-9. PMID3114190.
^Prott FJ, Haverkamp U, Willich N, Wagner W, Micke O, Pötter R (1996). "Ten years of fast neutron therapy in Münster". Bulletin du Cancer. Radiothérapie. 83 (Suppl): 115s–21s. doi:10.1016/0924-4212(96)84895-x. PMID8949762.
^Douglas, James G; Laramore, George E; Austin-Seymour, Mary; Koh, Wui-jin; Stelzer, Keith; Griffin, Thomas W (February 2000). "Treatment of locally advanced adenoid cystic carcinoma of the head and neck with neutron radiotherapy". International Journal of Radiation Oncology, Biology, Physics. 46 (3): 551–7. doi:10.1016/S0360-3016(99)00445-9. PMID10701733.
^Breteau N, Wachter T, Kerdraon R, et al. (2000).『Utilisation des neutrons rapides dans le traitement des tumeurs des glandes salivaires : rationnel, revue de la littérature et expérience d'Orléans』[Use of fast neutrons in the treatment of tumors of the salivary glands: rationale, review of the literature and experience in Orleans]. Cancer/Radiothérapie (in French). 4 (3): 181–90. doi:10.1016/S1278-3218(00)89092-7. PMID10897760.
^ abLee SC (23 December 2021). "Salivary Gland Neoplasms". Medscape. Updated: Jan 13, 2021 Diagrams by Mikael Häggström, MD
![Relative incidence of submandibular tumors, with adenoid cystic carcinoma being the second most common.[17]](http://en.wikipedia.org/wiki/File:Relative_incidence_of_submandibular_tumors.png)
![Relative incidence of parotid tumors, with adenoid cystic carcinoma being relatively rare.[17]](http://en.wikipedia.org/wiki/File:Relative_incidence_of_parotid_tumors.png)
