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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: 13 December 2024 (update in progress)

Copyright: 2002-2024, PathologyOutlines.com, Inc.

PubMed Search: Adenoid cystic carcinoma larynx

Table of Contents

Cite this page: Lee N, Ng T. Adenoid cystic carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/larynxacc.html. Accessed December 21st, 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)

Negative stains

Ductal: CK8, GCDFP-15
Myoepithelial: S100, vimentin, GFAP

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

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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Reference: Adenoid cystic carcinoma

Board review style question #2

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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Reference: Adenoid cystic carcinoma

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