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Updated: Jul 5, 2025
A Robust Discovery Platform for the Identification of Novel Mediators of Melanoma Metastasis
Published on: March 8, 2022
Melan-A expression in non-melanocytic carcinoma: A potential diagnostic pitfall
Linwei Zuo1, Huiyan You1, Zhe Cai1
1Department of Pathology, The Second Affiliated Hospital of Nanchang University, Nanchang, China.
Background:
Melan-A/MART-1 is a melanocytic differentiation marker recognized as an antigen on melanoma cells. It is a useful diagnostic marker for pathologists in the diagnosis of melanocytic tumors. However, we recently found that Melan-A can be expressed in some non-melanocytic carcinomas that are rarely reported in the literature.
Methods:
We analyzed the expression of Melan-A in 87 non-melanocytic carcinoma tissue samples by immunohistochemistry. Marker positivity was defined as ≥10% positive tumor cells.
Results:
In 87 non-melanocytic carcinoma tissue samples, Melan-A was positive in six (6.89%) cases, of which four (66.7%) were male and two (33.3%) were female, with a mean age of 60 years (range 21-82 years). Five (83.3%) of the Melan-A-positive cases had distant metastases. Compared with Melan-A negative cases, Melan-A positive non-melanocytic carcinomas were significantly associated with poor prognosis (P=0.0023).
Conclusions:
Melan-A expression is relatively rare in non-melanocytic carcinoma cases. This report highlights a potential diagnostic pitfall in the diagnosis of melanoma, urges pathologists to exercise caution in cases of Melan-A positivity, and illustrates the need for an immunohistochemical marker panel to avoid misdiagnosis.
