Oral cavity & oropharynx

Other tumors

Oral mucosal melanoma



Last author update: 1 November 2013
Last staff update: 22 August 2022

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PubMed Search: Melanoma oral cavity

Nat Pernick, M.D.
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Cite this page: Pernick N. Oral mucosal melanoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/oralcavitymelanoma.html. Accessed March 18th, 2024.
Definition / general
  • Rare; annual incidence of 1.2 cases per 10 million; more common in Japanese, black Africans, Native Americans and Hispanics
  • Median age 61 years, 78% men
  • Differs from cutaneous melanoma due to lack of association with sun damage, family history or atypical nevi and difference in prognostic factors
  • Nodal and distant metastases are common
  • References: Am J Surg Pathol 2001;25:782, Am J Surg Pathol 2002;26:883
Prognostic factors
  • Extremely poor prognosis, with median survival 2 - 3 years; some lower grade tumors without vascular invasion had median survival of 8 years
  • Poor prognostic factors: vascular invasion, polymorphous tumor cell population and necrosis
  • No prognostic value: tumor thickness, ulceration and level of invasion
Case reports
Gross description
  • Mucosa covering maxillary bone (62%), labial mucosa (13%) and lower gingiva (8%)
  • Usually flat, erythematous or pigmented, less commonly presents as a mass
Microscopic (histologic) description
  • Mean 3 mm thick; pigmented or frequently amelanotic; morphology includes epithelioid, fusiform and polymorphous cells
  • Some tumor giant cells in almost all cases; 90% have associated melanoma in situ; usually mitotic figures
  • Frequent ulceration, necrosis, vascular invasion and perineural invasion; may have desmoplastic features, particularly if lower lip
Microscopic (histologic) images

Case #419

Nests and nodules
of tumor cells with
melanin pigments

Tumor cells with
extensive necrosis
and melanin
pigments

PAP

HMB45 (cell block)


Giemsa

Positive stains
Negative stains
Differential diagnosis
  • Amelanotic melanomas:
    • Large cell lymphoma, poorly differentiated carcinoma
Board review style question #1
What do primary mucosal melanoma and cutaneous melanoma have in common?

  1. Both commonly have BRAF mutations
  2. Both use the same staging criteria
  3. Sun exposure is a risk factor for both
  4. They have a similar prognosis
  5. They have the same immunohistochemical profile
Board review style answer #1
E. They have the same immunohistochemical profiles. Primary mucosal melanomas share histologic and immunohistochemical features with cutaneous melanomas but differ in terms of risk factors, aggressiveness, molecular profiles and staging criteria.

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Reference: Melanoma
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