• To distinguish metastatic melanoma in lymph nodes from nodal nevi
• To distinguish melanoma from a subset of nevi

PRAME positivity is based on the percentage of cells staining. A 0-4 point staining scale is used. 4+ staining is defined as ≥ 75% of cells staining. PRAME is typically interpreted in conjunction with another melanocytic immunohistochemical stain.

Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• PRAME is positive in multiple epithelial tumors, seminomas, sarcomas, and melanoma. Normal tissues positive for PRAME: Testis, proliferative endometrium. PRAME clone EPR20330 stains normal sebaceous glands.
• PRAME positive epithelial tumors include: Sebaceous carcinomas, basal cell carcinoma, breast carcinoma, pulmonary nonsmall cell carcinoma,  ENT squamous cell carcinoma, renal cell carcinoma, clear cell carcinoma, endometrial carcinoma, uterine serous carcinoma, uterine carcinosarcoma, ovarian clear cell carcinoma, adenoid cystic carcinoma, thymic carcinoma, seminoma.
• PRAME positive sarcomas/neuroectodermal tumors include: Synovial sarcoma, myxoid liposarcoma, neuroblastoma. 

Staining pattern

• Nuclear
• Cytoplasmic can be seen in non-melanocytic tumors

References

1. Gradecki et al. PRAME expression in 155 cases of metastatic melanoma. J Cutan Pathol 2021;48;479-485.
2. Lezcano C et al. PRAME expression in melanocytic tumors. Am J Surg Pathol 2018;42(11):1456-1465.
3. Kaczorowski M et al. PRAME expression in cancer. A systemic immunohistochemical study of >5800 epithelial and nonepithelial tumors. Am J Surg Pathol 2022;46(11):1467-1476.