Salivary Gland Disorders
Mucoepidermoid Carcinoma
aka MEC
The most common malignant salivary gland tumour; composed of mucous, intermediate and epidermoid cells with CRTC1/MAML2 fusion driving pathogenesis.
§ figuresFigures (4)
Fig. 1Mucoepidermoid carcinoma is a rare lung tumor tht usually arises within the central bronchi. Typical cases contain mucus-secreting goblet cells, intermediate cells and squamous cells. Low grade tumors predominate and are
“Mucoepidermoid carcinoma, high grade Case 200 (6499875229)” · Yale Rosen from USA · CC BY-SA 2.0 · Wikimedia Commons
Fig. 2Touch imprint cytology of mucoepidermoid carcinoma showing intermediate cells and a mucin filled cell (H&E ×400)
“Touch prep cytology of mucoepidermoid carcinoma” · Naveed H, Abid M, Hashmi AA, Edhi MM, Sheikh AK, Mudassir G · CC BY 4.0 · Wikimedia Commons
Fig. 3Mucoepidermoid carcinoma is a rare lung tumor tht usually arises within the central bronchi. Typical cases contain mucus-secreting goblet cells, intermediate cells and squamous cells. Low grade tumors predominate and are
“Mucoepidermoid carcinoma, high grade Case 200 (6499875953)” · Yale Rosen from USA · CC BY-SA 2.0 · Wikimedia Commons
Fig. 4Mucoepidermoid carcinoma is a rare lung tumor tht usually arises within the central bronchi. Typical cases contain mucus-secreting goblet cells, intermediate cells and squamous cells. Low grade tumors predominate and are
“Mucoepidermoid carcinoma, high grade Case 200 (6499881527)” · Yale Rosen from USA · CC BY-SA 2.0 · Wikimedia Commons
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Mucoepidermoid Carcinoma figures pending faculty review.
§ overviewOverview
Malignant epithelial salivary gland neoplasm characterised by variable proportions of mucous, intermediate and squamoid cells.
§ icdICD Classification
C07/C08
§ etiologyEtiology
- 01Sporadic; ionising radiation increases risk
- 02CRTC1(MECT1)-MAML2 fusion in ≈50–70%
§ epidemiologyEpidemiology
≈30% of salivary malignancies; parotid > minor glands (palate); commonest salivary malignancy in children.
§ clinicalClinical Features
- 01Painless slow-growing swelling (low grade) — may mimic mucocele on palate
- 02Rapidly growing painful mass with fixation, facial nerve palsy (high grade)
- 03Fluctuant bluish palatal swelling common
§ differentialDifferential Diagnosis
- 01Pleomorphic adenoma
- 02Mucocele (minor glands)
- 03Adenoid cystic carcinoma
- 04SCC
§ histopathHistopathology
- 01Mixture of mucous (goblet), intermediate and epidermoid cells
- 02Cystic spaces (low grade) → solid sheets with atypia (high grade)
- 03Mucicarmine and PAS-diastase stain mucous cells
§ investigationsInvestigations
- 01MRI (soft-tissue detail, perineural spread)
- 02FNAC / core biopsy
- 03CT chest for staging
§ ihcIHC / Special Stains
- 01CK7+, p63 in epidermoid cells
- 02MAML2 FISH for confirmation
§ classificationClassification
- 01Grading systems: AFIP, Brandwein, MSK — based on cystic component, invasion, necrosis, mitoses, perineural spread
- 02Low, intermediate, high grade
§ treatmentTreatment
- 01Wide local excision with clear margins
- 02Parotid: superficial or total parotidectomy with facial nerve preservation
- 03Neck dissection for high-grade / cN+
- 04Adjuvant radiotherapy for high-grade, positive margins, perineural or vascular invasion
- 05Chemotherapy for palliation
§ complicationsComplications
- 01Facial nerve injury
- 02Recurrence (high grade)
- 03Distant metastases (lung, bone) in high-grade
§ prognosisPrognosis
5-year survival: low grade >90%, intermediate ~70%, high grade 30–50%.
§ examKey Examination Points
- 01Bluish palatal swelling in adult → not a mucocele until proven otherwise
- 02Always image before biopsy of parotid mass
§ revisionQuick Revision Summary
- 01MAML2 fusion · commonest paediatric salivary malignancy · grade determines prognosis
§ vivaBDS Viva Questions
- 01Diagnostic translocation of MEC?
- 02Grading criteria?
- 03Approach to parotid MEC?
§ mcqsMCQs — Assessment (3)
Question 1
Most common malignant salivary gland tumour:
Question 2
Characteristic gene fusion:
Question 3
Commonest intraoral site:
§ evidenceReferences & Evidence
Current Classification
WHO Classification of Head and Neck Tumours
5th Edition — Volume 9
WHO Classification of Tumours Editorial Board · 2022
The authoritative international classification of head and neck, odontogenic and salivary gland tumours. Current terminology on this site follows this edition.
Evidence summary
Highest level of evidence linked to this page: WHO / Official Classification.
- L1 · Classification — 3
- L6 · Textbook — 3
1 linked source was published from 2024 onwards. Where guidance is limited or contested, rely on the higher-level sources above rather than this summary. Educational use only — not a substitute for clinical judgement.
Content last reviewed
September 2026
Evidence last reviewed
September 2026
Next scheduled review
September 2027
Review status
EVIDENCE REVIEWED
Search latest PubMed evidence
Last literature search: 7 September 2026
Current Classification
WHO Classification of Tumours Editorial Board. IARC / World Health Organization · 2022
The authoritative international classification of head and neck, odontogenic and salivary gland tumours. Current terminology on this site follows this edition.
Skálová A, Hyrcza MD, Leivo I. Head and neck pathology · 2022 · 16(1):40-53
Summary of changes to salivary gland tumours in the 5th edition WHO classification of head and neck tumours.
IARC / WHO. IARC · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Histopathology References
Barnes L. CRC Press · 2008
Detailed histopathological reference for head and neck diagnostic criteria.
Textbook References
Neville BW, Damm DD, Allen CM et al.. Elsevier · 2024
Standard reference textbook of oral and maxillofacial pathology used throughout this atlas.
Rajendran R, Sivapathasundharam B. Elsevier · 2020
Undergraduate and postgraduate oral pathology textbook widely used in BDS and FCPS curricula.
Additional sources cited on this page
- WHO Head & Neck Tumours 2022
Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.