Oral cavity & oropharynx
Neuroectodermal
Melanoma


Topic Completed: 1 November 2013

Revised: 24 May 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Melanoma[TI] oral cavity[TI]

Nat Pernick, M.D.
Page views in 2018: 1,376
Page views in 2019 to date: 2,374
Cite this page: Pernick N. Melanoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/oralcavitymelanoma.html. Accessed October 22nd, 2019.
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 of the Week #419

Nests and nodules
of tumor cells with
melanin pigments

Tumor cells with
extensive necrosis
and melanin pigments

PAP

HMB45 (cell block)


Giemsa



Images hosted on other servers:

In situ and invasive

H&E and stains

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

A. Both commonly have BRAF mutations.
B. Both use the same staging criteria.
C. Sun exposure is a risk factor for both.
D. They have a similar prognosis.
E. They have the same immunohistochemical profile.
Board review 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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