Mohs micrographic surgery with MART-1 immunostains targets lentigo maligna

Key Points

Pittsburgh - To successfully treat lentigo maligna melanoma and its precursor, lentigo maligna, Mohs micrographic surgery using MART-1 immunostains is a technique touted by experts, according to David Brodland, M.D., who practices in Pittsburgh.

"It can be very difficult to visually delineate the edges of the cancer, and Mohs surgery is a great way to circumvent the difficulty in identifying the true melanoma margins," says Dr. Brodland, assistant professor, departments of dermatology and otolaryngology, University of Pittsburgh.

"The sections that we cut are 2 microns and the normal section thickness may be up to 6 to 8 microns, so they are very thin, and that is necessary because the MART-1 stains are most effective in very, very thin sections," Dr. Brodland says.

Examining lentigo maligna

The sun freckle, or sun spot, called the lentigo, is in some cases a precursor to lentigo maligna.

"A clinician may see 1,000 or more lentigines for every one that becomes a melanoma. Lentigo maligna is essentially the same in as a melanoma in situ (noninvasive)," Dr. Brodland says. "In my practice, I consider any melanoma in situ equivalent to lentigo maligna. When the pathologist sees the tumor location in sun-exposed skin and adjacent sun damage along with other criteria used to distinguish between melanoma in situ and lentigo maligna, they will specify the lentigo maligna subtype."