Salivary glands
Primary salivary gland neoplasms
Malignant
Mucoepidermoid carcinoma
Authors: Adriana Handra-Luca, M.D., Jen-Fan Hang, M.D.
Topic Completed: 1 September 2012
Minor changes: 10 July 2020
Copyright: 2003-2020, PathologyOutlines.com, Inc.
PubMed Search: Mucoepidermoid carcinoma[TI] salivary gland[TI]
See also: Oncocytic mucoepidermoid carcinoma
Table of Contents
Definition / general | Clinical features | Prognostic factors | Case reports | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Electron microscopy description | Electron microscopy images | Molecular / cytogenetics description | Differential diagnosis | Board review style question #1 | Board review answer #1Cite this page: Handra-Luca A, Hang JF. Mucoepidermoid carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/salivaryglandsMEC.html. Accessed September 29th, 2020.
Definition / general
- Cords, sheets and clusters of mucous, squamous, intermediate and clear cells
- Most common malignant tumor in salivary glands
- Also most common radiation induced neoplasm
Clinical features
- 2/3 occur in parotid gland; also in palate
- Wide age range, mean 49 years, range 15 - 86 years, no gender predominance
- Low grade: 15% recur, 5 year survival 90 - 98%, usually stage I
- High grade: 25% recur, 5 year survival 50 - 56%, deaths usually within first 5 years
- Note: significant grading disparity exists between pathologists (Am J Surg Pathol 2001;25:835)
AFIP point system:
- 2 points if < 20% intracystic component
- 2 points if neural invasion
- 3 points if necrosis
- 3 points if 4+ mitotic figures/10 HPF
- 4 points if anaplasia
- Low grade if total score is 0 - 4 points, intermediate grade if 5 - 6 points, high grade if 7+ points
Prognostic factors
- Poor prognostic factors: older age, male, submandibular gland, extraglandular extension, vascular invasion, necrosis, high mitotic rate, high histologic grade
Case reports
- 4 year old boy with soft tissue mass in cheek (Case of the Week #346)
- 55 year old man with low grade parotid tumor and dedifferentiation (Hum Pathol 2003;34:1068)
Treatment
- Complete excision, possibly radiation therapy
Gross description
- Low grade: well circumscribed with gray-white, mucin filled cysts
Microscopic (histologic) description
- Cords, sheets and clusters of mucous, squamous, intermediate and clear cells
- Low to high grade, although even high grade tumors lack marked nuclear atypia, frequent mitotic figures or extensive necrosis
- Occasional focal sebaceous cells, goblet type cells, oncocytic change, inflammatory reaction to extravasated mucin or keratin
- No squamous cell carcinoma in situ
- Low grade: mucinous and intermediate cells with bland nuclei form glandular spaces
- High grade: solid and infiltrative growth pattern of atypical epidermoid and intermediate cells with cytoplasmic clearing and small number of mucinous cells; < 20% intracystic component
Microscopic (histologic) images
Case #346
4 year old boy
Ki67
Mucicarmine
Images hosted on other servers:
Cases in children
Spindled morphology
Cytology description
- Most often graded as low grade and high grade in FNA
- Admixture of epidermoid, intermediate and mucus cells
- Cystic background with abundant extracellular mucin
- Low grade mucoepidermoid carcinoma: bland epithelial cells and abundant extracellular mucin
- High grade mucoepidermoid carcinoma: predominantly epidermoid cells with marked cytologic atypia
- Lymphocytes can be present in 20% of cases and sometimes are abundant
Cytology images
Images hosted on other servers:
Low grade with background mucin, two
types of cells with bland nuclear features
(squamoid with dense cytoplasm and
glandular with vacuolated cytoplasm)
High grade with malignant squamous cells
Low grade and oncocytic tumors
Positive stains
- Low grade: CK7, CK14, antimitochondrial antibodies
- p63 / p40 in epidermoid and intermediate cells
- Mucicarmine stain in the intracytoplasmic mucin of mucus cells
Negative stains
- SOX10 in epidermoid and intermediate cells
Electron microscopy description
- Mixed luminal epithelial cells and myoepithelial cells
Electron microscopy images
Images hosted on other servers:
Spindled morphology
Molecular / cytogenetics description
- Associated with t(11;19)(q14-21;p12-13)
Differential diagnosis
- Adenosquamous carcinoma: has anaplastic nuclear features
- Metastatic carcinoma
- Necrotizing sialometaplasia
- Poorly differentiated adenocarcinoma
Board review style question #1
Which histological diagnosis is most likely to correspond to this cytologic aspirate?
- Acinic cell carcinoma
- Adenoid cystic carcinoma
- Mucoepidermoid carcinoma
- Secretory carcinoma
Board review answer #1
C. Mucoepidermoid carcinoma
A fragment of intermediate cells with intermingled mucous cells containing orange colored intracytoplasmic mucin is characteristic for a mucoepidermoid carcinoma.
Comment Here
Reference: Mucoepidermoid carcinoma
A fragment of intermediate cells with intermingled mucous cells containing orange colored intracytoplasmic mucin is characteristic for a mucoepidermoid carcinoma.
Comment Here
Reference: Mucoepidermoid carcinoma
