A lesion that initially caused no difficulty
An 82-year-old Iranian woman had worn a maxillary denture for approximately 20 years. Four years before biopsy, she noticed a small, painless lesion on her palate.
Because the lesion did not interfere with the denture, she did not seek medical evaluation. It gradually enlarged, and approximately one year before biopsy it became large enough to prevent continued denture use.
At presentation, examination showed a large, lobulated, exophytic palatal mass with pigmented, erythematous, and hemorrhagic areas.
The painless course may have been reassuring. The pattern of progressive growth was not.
The significance of pigmentation and bone change
The exophytic and hemorrhagic appearance initially allowed consideration of a reactive lesion. Pigmentation, however, provided an important clue to melanocytic disease.
Panoramic radiography showed focal irregular osseous destruction in the right maxillary region. This raised concern for locally aggressive disease but could not establish bone invasion because CT, MRI, or histological sampling of the bone was not performed.
An incisional biopsy was therefore essential.
Pathology identifies the lesion
Histopathological examination showed an infiltrative malignant neoplasm composed of atypical melanocytic cells arranged in sheets. The cells demonstrated nuclear pleomorphism, prominent nucleoli, and invasion into the underlying connective tissue.
Immunohistochemistry showed:
- S-100 positivity;
- HMB-45 positivity;
- p16 negativity; and
- a Ki-67 labeling index of approximately 20%.
The clinical, morphological, and immunohistochemical findings supported a diagnosis of oral mucosal melanoma.
The Ki-67 value was reported descriptively. The authors appropriately did not use it as an independent prognostic classification because a sufficiently standardized case-level cutoff was unavailable.
Why painless oral lesions can be deceptive
Oral mucosal melanoma may present as a pigmented macule, nodule, ulcerated lesion, or exophytic mass. The palate and maxillary gingiva are commonly affected sites.
Symptoms may be minimal during early disease. Consequently, an oral lesion may enlarge substantially before pain, bleeding, impaired denture fit, dysphagia, or another functional problem leads to assessment.
The practical warning extends beyond melanoma: persistence and progression carry diagnostic importance even when an oral lesion is painless.
Important uncertainty in this case
No formal CT, MRI, PET/CT, or equivalent staging investigation was documented. The local extent of the lesion and the presence or absence of nodal or distant metastases therefore remained unknown.
No definitive tumor-directed treatment was recorded. The patient died approximately two months after oncological consultation, but the cause of death was not documented.
It would therefore be inappropriate to assign a stage retrospectively or state that metastatic melanoma caused her death.
Clinical Take-Home Message
A persistent or progressively enlarging oral lesion should be evaluated even when it is painless.
Pigmentation, hemorrhage, progressive enlargement, impaired denture fit, or radiographic bone destruction should heighten concern for malignancy and prompt timely biopsy. Once oral mucosal melanoma is diagnosed, complete staging is necessary to define disease extent and guide management.
This case also demonstrates the importance of preserving uncertainty: the biopsy established oral mucosal melanoma, but the absence of formal staging prevented conclusions about its full extent, and the recorded information did not establish the cause of the patient’s subsequent death.
Journal of Medical Case Reports is the world’s first international, PubMed-listed medical journal devoted to publishing case reports from all medical disciplines and will consider any original case report that expands the field of general medical knowledge, and original research relating to case reports. The journal is open access and strongly endorses the CARE guidelines for case reports, requiring authors to submit populated CARE checklists with submissions to improve transparency in reporting.
Based on: Javadzadeh F, Hosseinpour Sarmadi M, Zohrabi M, et al. Oral mucosal melanoma presenting as a large exophytic palatal mass in an elderly patient: a case report. Journal of Medical Case Reports. Published 30 September 2026. https://doi.org/10.1186/s13256-026-06663-y