Larynx, hypopharynx & trachea
Other malignancies
Adenoid cystic carcinoma
Authors: Nathan Lee, D.M.D., Tony Ng, M.D., Ph.D.
Editorial Board Member: Kelly Magliocca, D.D.S., M.P.H.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 18 June 2019
Last staff update: 27 June 2022
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Adenoid cystic carcinoma larynx
Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Lee N, Ng T. Adenoid cystic carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/larynxacc.html. Accessed April 24th, 2024.
Definition / general
- Most common laryngeal minor salivary gland neoplasm (Laryngoscope 2015;125:2485)
- Only about 142 cases have been reported as of April 2016 (Adv Ther 2016;33:553)
- Same histology as salivary gland tumors (Am J Otolaryngol 2012;33:226)
Essential features
- Slow growing salivary gland tumor that can also be found in the larynx
- Presents at late stage; difficult to achieve clear surgical margins
- Various histologic patterns including tubular, cribriform, solid (similar to the oral cavity)
ICD coding
- ICD-O: 8200/3 - adenoid cystic carcinoma
Epidemiology
- M = F (Otolaryngol Head Neck Surg 2016;154:433)
- Occurs over a wide age range but most commonly presents in the sixth to eighth decade (El-Naggar: WHO Classification of Head and Neck Tumours, 4th Edition, 2017)
Sites
- Most commonly subglottic (60%) (Adv Ther 2016;33:553)
- Can be supraglottic (30%) or involve the true vocal cords (10%) (Adv Ther 2016;33:553)
- Location is possibly due to the presence of more subepithelial glands in those areas (Head Neck 2008;30:919)
Pathophysiology
- Arises from subepithelial glands (Otolaryngol Head Neck Surg 2016;154:433)
- Associated with t(6;9)(q22-23;p23-24) translocation creating a fusion gene between MYB proto-oncogene and NFIB transcription factor gene (Mod Pathol 2011;24:1169)
- Overall, 56/68 (82%) of adenoid cystic carcinomas expressed MYB-NFIB fusion in a study by Brill et al.; of those 2/5 (40%) were from the larynx (Mod Pathol 2011;24:1169)
- This chromosomal rearrangement juxtaposes super enhancers to the MYB locus to create a positive feedback loop elicited when the MYB protein activates these enhancers (Oncotarget 2016;7:66239)
- Fusion between MYBL1 and NFIB genes without MYB aberration have been identified, demonstrating that tumor development may also be driven by genetic alterations in different members of the same transcription factor family (Oncotarget 2016;7:66239)
Etiology
- Exact cause is currently unknown (Oncol Lett 2015;10:2303)
- Specific risk factors have not yet been identified, smoking does not affect the incidence unlike squamous cell carcinomas (Acta Otorhinolaryngol Ital 2009;29:279)
Clinical features
- Slow growing (Otolaryngol Head Neck Surg 2016;154:433)
- Symptoms include pain (secondary to perineural invasion), dyspnea, hoarseness, dysphagia (Head Neck 2008;30:919)
- Neck metastasis is rare (Adv Ther 2016;33:553)
Prognostic factors
- Often presents at late stage (Otolaryngol Head Neck Surg 2016;154:433)
- Negative margin status is associated with long term survival (Am J Otolaryngol 2012;33:226)
- May be associated with squamous cell carcinoma, particularly if supraglottic and either high grade or solid variants; these cases are extremely aggressive (Ann Thorac Surg 2004;78:1889)
Case reports
- 33 year old woman nonsmoker with subglottic stenosis (Auris Nasus Larynx 2016;43:562)
- 40 year old woman nonsmoker with coexisting bronchoconstriction and asthma (Oncol Lett 2015;10:2303)
- 44 year old woman treated with partial laryngectomy without neck dissection for pT3 adenoid cystic carcinoma (Oncol Lett 2015;10:2303)
- 55 year old man nonsmoker with prelaryngeal pain (Acta Otorhinolaryngol Ital 2009;29:279)
- 70 year old man with a history of smoking and coexisting diabetes mellitus and chronic renal failure (Oncol Lett 2018;16:2783)
Treatment
- Surgery, but clinical margins are difficult due to prevalent perineural invasion (Am J Otolaryngol 2012;33:226)
- Recurrent lesions are associated with unfavorable clinical course (Head Neck 2008;30:919)
- Efficacy of radiotherapy and the radiosensitivity of adenoid cystic carcinoma is not clear (Otolaryngol Head Neck Surg 2016;154:433)
Clinical images
Images hosted on other servers:
Bulging vocal cord mass
Gross description
- Smooth intact surface without ulceration (Oncol Lett 2015;10:2303)
- Firm submucosal mass (Head Neck 2008;30:919)
- Frequent lateral submucosal spread, resulting in detection only at late stage (Am J Otolaryngol 2012;33:226)
Microscopic (histologic) description
- Ductal cells: hyperchromatic angular nuclei, may have clear cytoplasm (Oral Oncol 2006;42:57)
- Myoepithelial cells: flattened nuclei (Oral Oncol 2006;42:57)
- Tubular pattern: multiple duct-to-tubule-like structures lined by multiple layers consisting of ductal or myoepithelial cells or both, uniform small cuboidal tumor cells, few mitotic figures (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:495)
- Cribriform pattern: islands of epithelioid basal cells, cystic spaces contain mucoid or hyalinized material, uniform small cuboidal tumor cells, few mitotic figures (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:495)
- Solid pattern: large solid sheets of tumor cells, may have focal central necrosis within tumor islands, pleomorphic tumor cells, many mitotic figures (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:495)
Microscopic (histologic) images
Contributed by Vancouver General Hospital
Characteristic histologic features
Involvement of the trachea
Positive stains
- Ductal: CK7, EMA, SOX10
- Myoepithelial: p63, SMA, calponin
- CD43 (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:495), CD117 / KIT (Oral Oncol 2006;42:57)
Molecular / cytogenetics description
- Associated with MYB-NFIB fusion gene (Mod Pathol 2011;24:1169)
- More recently MYBL1-NFIB fusion gene has also been identified (Oncotarget 2016;7:66239)
Sample pathology report
- Larynx, resection:
- Adenoid cystic carcinoma, differentiated tubular and cribriform growth patterns (see synoptic report)
- Maximum tumor size: at least 9 cm
- Tumor extensively involves lateral paratracheal and paralaryngeal margins
- Vocal cords and pyriform sinus negative for malignancy
- Perineural invasion present
Differential diagnosis
- Pleomorphic adenoma:
- Multiple patterns of growth and bland
- Polymorphous adenocarcinoma:
- Negative for CD117 / KIT staining
- Epithelial myoepithelial carcinoma:
- Consistent biphasic pattern of ductal cells with surrounding myoepithelial cells
- Basaloid squamous cell carcinoma:
- Peripheral palisading around nests with central comedonecrosis surrounded by hyalinized stroma
Board review style question #1
- Which of the following is true about this adenoid cystic carcinoma of the larynx?
- Immunohistochemical staining for CD117 will be negative in tumor cells
- Perineural invasion is extremely rare in this type of tumor
- The cystic spaces contain mucoid or hyalinized material
- The primary site of laryngeal adenoid cystic carcinoma is the vocal cords themselves
- This tumor is clinically aggressive, reflected by the high mitotic rate and basaloid cells
Board review style answer #1
C. The cystic spaces contain mucoid or hyalinized material. These spaces often contain a mildly basophilic mucoid material, a hyalinized eosinophilic product or a combined mucoid hyalinized appearance.
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Board review style question #2
- What is the most common malignant minor salivary gland tumor of the larynx?
- Acinic cell carcinoma
- Adenoid cystic carcinoma
- Mucoepidermoid carcinoma
- Pleomorphic adenoma
- Polymorphous adenocarcinoma
Board review style answer #2
B. Adenoid cystic carcinoma. While minor salivary gland tumors of the larynx are rare overall, adenoid cystic carcinoma is the most common malignant entity in this location.
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