Mucoepidermoid carcinoma

Salivary glands
Primary salivary gland neoplasms - malignant
Mucoepidermoid carcinoma

Topic Completed: 1 September 2012

Minor changes: 3 March 2020

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PubMed Search: Mucoepidermoid carcinoma[TI] salivary gland[TI]

See also: Oncocytic mucoepidermoid carcinoma

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Table of Contents

Cite this page: Handra-Luca A. Mucoepidermoid carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/salivaryglandsMEC.html. Accessed July 7th, 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 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)