ORLANDO Reflectance confocal microscopy can be used as an aid to the clinical exam to help detect either incomplete treatment or recurrence of lentigo maligna and lentigo maligna melanomas that have been treated with nonsurgical methods, a resident in dermatologic surgery said.
After being treated nonsurgically with imiquimod, two patients with biopsy-proven lentigo maligna melanomas were monitored with the aid of reflectance confocal microscopy. In both cases, suspicious areas were detected and were later confirmed to be residual disease on biopsy.
Such cases illustrate the importance of closely following patients with lentigo maligna who are treated with alternative therapies, said Dr. Hari Nadiminti of Memorial Sloan Kettering Cancer Center, New York.
Surgical excision remains the standard of care for treatment of lentigo maligna and lentigo maligna melanoma, but it can be associated with significant morbidity, Dr. Nadiminti said at the annual meeting of the American Society for Dermatologic Surgery.
Alternatives to surgery include cryotherapy, radiotherapy, and topical 5% imiquimod.
Reflectance confocal microscopy is a high-resolution, painless imaging technique that reveals epidermal structures including cells, connective tissue, and blood vessels to a maximum depth of 350 mcm. It has been used to diagnose pigmented basal cell carcinoma and to differentiate between benign and malignant melanocytic lesions and actinic keratoses from normal skin.
Dr. Nadiminti presented five cases to illustrate how microscopy can be useful in monitoring lentigo maligna and lentigo maligna melanoma patients who opt for nonsurgical treatment.
In the first three cases, patients aged 87, 85, and 76 years opted for treatment with imiquimod. In all of these cases, patients had a significant inflammatory response to imiquimod and clinical clearance of pigment after 3 months of treatment.
Reflectance confocal microscopy demonstrated no residual bright structures as well as remodeling of the collagen into a honeycomb pattern in some instances. A confirmatory biopsy revealed no residual melanoma.
In the next two cases, reflectance confocal microscopy revealed persistence of lentigo maligna melanoma after treatment with imiquimod in one case and cryosurgery in the other. Pigmentation cleared completely in one patient and partially in the other. Upon examination with reflectance confocal microscopy, bright structures were observed, and biopsy confirmed the persistence of lentigo maligna melanoma.
After nonsurgical therapies, patients should be followed very closely to monitor for either incomplete treatment or recurrence, Dr. Nadiminti said.
"Even though you have clearance of the pigment with imiquimod, you don't necessarily have clearance of the tumor," he said.
Dr. Nadiminti disclosed no conflicts of interest relevant to his presentation.