Table of Contents
Definition / general | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Tranesh G. Mucoepidermoid carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticmuc.html. Accessed January 22nd, 2021.
Definition / general
- Very rare in skin (~30 cases reported)
- Probable sweat gland origin
- Resembles similar tumor of salivary gland
- Usually low to intermediate grade, some higher grade tumors perhaps better classified as adenosquamous carcinoma
Case reports
- 66 year old man with ear tumor (J Cutan Pathol 1991;18:56)
- 72 year old man with tumor arising within nevus sebaceus of Jadassohn on forehead (J Cutan Pathol 2003;30:652)
- 76 and 79 year old men (Int J Surg Pathol 2015;23:161, Am J Surg Pathol 2005;29:131) with tumors of cheek and axilla
- 81 year old man with tumor infiltrating parotid gland (Eur Rev Med Pharmacol Sci 2012;16:26)
Gross description
- Up to 0.6 cm, ulcerated and nonencapsulated
- Flesh colored nodules, painless
Microscopic (histologic) description
- Circumscribed tumor, may not be attached to surface
- Multilobulated nodulocystic tumor extending throughout dermis, exhibiting glandular and squamoid differentiation
- Dermal lobules or cystic growth of low grade epidermoid, intermediate, mucinous cells and clear cells
- Cribiform nests of epidermoid cells contain glandular spaces with mucin
- Nuclei are mildly atypical and contain scattered mitotic figures
- Peritumoral fibrosis is common
- May have focal perineural invasion
Microscopic (histologic) images
Molecular / cytogenetics description
- CRTC1 rearrangements have been detected in cutaneous MEC (like salivary gland MEC), but translocation t(11,19) or MAML2 rearrangements not seen (unlike salivary gland MEC) (Br J Dermatol 2009;161:925)
Differential diagnosis
- Adenosquamous carcinoma: high grade tumor, often involves epidermis, adenocarcinoma component is well-differentiated
- Metastatic salivary gland tumor: usually high grade
- Mucinous metaplasia