Desmoplastic melanocytic nevi with lymphocytic aggregates

Area of Science:

• Dermatopathology
• Oncology
• Histopathology

Background:

• Desmoplastic melanocytic nevi present diagnostic challenges, often mimicking desmoplastic melanoma.
• Lymphocytic aggregates are frequently associated with desmoplastic melanoma but lack specificity.

Purpose of the Study:

• To report cases of sclerosing melanocytic nevi with associated lymphocytic aggregates.
• To emphasize the importance of comprehensive histopathologic and molecular evaluation in differentiating benign nevi from melanoma.

Main Methods:

• Histopathologic examination of six sclerosing melanocytic nevi.
• Immunohistochemical studies (Melan-A, p16).
• Fluorescence in situ hybridization (FISH) for chromosomal abnormalities.

Main Results:

• Six cases of benign sclerosing melanocytic nevi with lymphocytic aggregates were identified.
• All lesions showed strong Melan-A and p16 expression.
• FISH analysis revealed no copy number changes in 11p, 6q, or 6p in tested lesions.
• No recurrences were observed.

Conclusions:

• Lymphocytic aggregates alone are insufficient for diagnosing desmoplastic melanoma.
• Contextual histopathologic features and ancillary studies are crucial for accurate diagnosis.
• Sclerosing melanocytic nevi with lymphocytic infiltration can be benign.