Surgical management of melanoma
Guidelines contain details of thickness, diameter of area to excise
Malignant melanoma is still probably best treated by surgical management, according to Keyvan Nouri, M.D., director of dermatologic surgery at the University of Miami Miller School of Medicine in Florida.
“If we can treat the melanoma early enough, with surgery, this will provide the best chance for patients to survive their cancer,” Dr. Nouri tells Dermatology Times, following his presentation on current guidelines for surgical management of malignant melanoma at the American Academy of Dermatology (AAD) annual meeting in March.
Guidelines are from the AAD and the National Comprehensive Cancer Network (NCCN).
The biopsy of choice is an excisional biopsy, in an effort to remove the entire lesion with a 2 mm to 3 mm margin around the lesion. The specimen is then sent to pathology for diagnosis.
“Depending on the diagnosis, you can do further treatments,” Dr. Nouri says. “If the lesion is benign, obviously, nothing more needs to be done. However, if the lesion is moderately to severely dysplastic, and the margins are not adequate, you will need to remove an additional 2 mm to 3 mm margin around the lesion.”
Similarly, if the lesion is melanoma in situ, a margin of roughly 5 mm around the area is required.
All surgical management is determined by Breslow thickness, which is a measurement from the granular layer of the skin in the pathology to the lowest cells of melanoma that can be observed under microscope.
If the lesion is more than in situ, “the melanoma is invading into the dermis,” Dr. Nouri explains. “If the melanoma is less than 1 mm in Breslow thickness, usually a sentinel lymph node biopsy (SLNB) is not required. However, in rare cases, the threshold for a SLNB is lowered to 0.75 mm.”
Conversely, if the melanoma is deeper than 1 mm in Breslow thickness, the standard recommendation is a SLNB, along with a wide local incision.
If the depth of the lesion is less than 2 mm, a 1 mm margin is generally adequate. But if the depth of lesion is more than 2 mm, then a 2 mm or greater margin is required around the lesion.
“Generally, one wants to remove the melanoma lesion down to the deep fat or close to the fascia to remove the lesion entirely,” Dr. Nouri says.
Mohs surgery has also been used to treat melanoma, mainly for lentigo malagna and in situ melanoma.
“One of the advantages of Mohs surgery is better margin control,” says Dr. Nouri. “However, most of the time, special immunohistochemistry staining is required, which is time-consuming. Mohs surgery is also more technically difficult to perform than a standard excision and takes longer to perform.”
Going forward, Dr. Nouri expects Mohs surgery to become easier and simpler to perform.
“The special staining might also be much faster to do than what we currently do in the office, which now takes between one and two hours” he says.
Imaging devices might improve as well. By using confocal microscopy, for instance, one can better delineate the extent and depth of the tumor in vivo, instead of “assuming and guessing that a surgical excision of 1 or 2 mm will be enough,” Dr. Nouri says.
Dr. Nouri reports no relevant financial disclosures.