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Published on: March 8, 2022
PRAME Immunohistochemistry as an Ancillary Test for the Assessment of Melanocytic Lesions
Cecilia Lezcano1, Achim A Jungbluth1, Klaus J Busam1
1Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Abstract:
PRAME (PReferentially expressed Antigen in MElanoma) is a melanoma-associated antigen expressed in cutaneous and ocular melanomas and some other malignant neoplasms, while its expression in normal tissue and benign tumors is limited. Detection of PRAME protein expression by immunohistochemistry in a cohort of 400 melanocytic tumors showed diffuse nuclear immunoreactivity for PRAME in most metastatic and primary melanomas. In contrast, most nevi were negative for PRAME or showed nondiffuse immunoreactivity. The difference in the extent of immunoreactivity for PRAME in unambiguous melanocytic tumors prompted the study of PRAME as an ancillary tool for evaluating melanocytic lesions in more challenging scenarios.
Insights
PRAME protein is highly expressed in melanomas but not nevi. This finding suggests PRAME is a valuable biomarker for diagnosing challenging melanocytic lesions.
Area of Science:
- Oncology
- Dermatopathology
- Immunohistochemistry
Background:
- PRAME (PReferentially expressed Antigen in MElanoma) is a tumor antigen.
- It is expressed in various cancers, including melanoma, but limited in normal tissues.
- Its differential expression pattern suggests diagnostic potential.
Purpose of the Study:
- To investigate the utility of PRAME as a diagnostic marker for melanocytic lesions.
- To compare PRAME expression in melanomas versus nevi.
Main Methods:
- Immunohistochemistry was used to detect PRAME protein expression.
- A cohort of 400 melanocytic tumors, including primary melanomas, metastatic melanomas, and nevi, was analyzed.
Main Results:
- Diffuse nuclear PRAME immunoreactivity was observed in most primary and metastatic melanomas.
- Nevi typically showed negative or weak, nondiffuse PRAME immunoreactivity.
- A significant difference in PRAME expression was found between melanomas and nevi.
Conclusions:
- PRAME protein expression is a reliable indicator distinguishing melanomas from nevi.
- PRAME serves as a valuable ancillary tool in evaluating challenging melanocytic lesions.
- Immunohistochemical detection of PRAME can aid in melanoma diagnosis.
