PAM is a potentially cancerous lesion of the conjunctiva, which has a higher risk of transforming into a
melanoma in white persons. Nearly 75% of all melanomas that arise from the conjunctiva have been found to have occurred in the setting of PAM. It is different from BCEM because there is a proliferation, or an increase in the number of melanocytes, which is attributed to greater risk of
neoplasia formation. However, PAM may occur without
atypia, which has no risk of malignant transformation, or with atypia. It is very important to determine at which age the lesion was first noticed because it is more likely to be a benign
nevus, or mole, the earlier it is found. It may appear similar to BCEM since the lesion may also be flat, brown or blue-gray, and diffuse throughout the conjunctiva, but it is almost always only found on one eye.
Diagnosis • Usually unilateral, flat, patchy, pigmented area that involves the limbus (the border of the
cornea and
sclera) and interpalpebral (between the eyelids) conjunctiva. • Increasing size or size greater than 5mm • Involvement of conjunctiva underneath the eyelids • Nodular appearance • Appearance of blood vessels surrounding the patch • Previous history of melanoma
Treatment There are a few management and treatment strategies for PAM. When lesions are small, they can be carefully watched on an annual basis. It is important to compare pictures year to year. However, for medium and large-sized lesions, we can consider surgery (excisional vs incisional biopsy), chemotherapy, or cryotherapy. ==References==