Which conjunctival lesion is most likely to progress into a conjunctival melanoma?

• A. Conjunctival concretions
• B. Conjunctival nevus
• C. Primary Acquired Melanosis
• D. Conjunctival cysts

Answer: (C)

Primary Acquired Melanosis is the lesion with malignant potential on the conjunctiva, especially when atypia is present. It represents an acquired proliferation of melanocytes that can progress to conjunctival melanoma over time. The key is that PAM, unlike a nevus or benign cysts/concretions, can harbor atypical melanocytes in the epithelium, and that atypia markedly raises the risk of malignant transformation.

Conjunctival nevus is a benign melanocytic lesion that is usually stable and far less likely to become melanoma. Concretions are calcified deposits, and conjunctival cysts are fluid-filled lesions; neither carries meaningful risk of malignant change. So PAM stands out as the lesion with the highest progression potential to melanoma.