Hensin Tsao, MD, PhD
Ilona Frieden, MD
Ashfaq Marghoob, MD
Whitney High, MD, JD
Keith Flaherty MD
We should remember during examination and diagnosis that the number of nevi is a risk factor for melanoma. Especially when they vary in shape, size, and color. Literature supports the notion that the number of nevi (DN) can be (non-obligate) precursors to melanoma or (at least) that melanoma can arise in association with DN. However, 1-3% of new or changed lesions will be melanoma. Dermoscopy has provided a means for us to increase our sensitivity and specificity in the evaluation of new or changed lesions.
These tumors are a particularly difficult issue for dermatologists and dermatologic pathologists. Spitz tumors may be classified as Spitz nevi (which are benign), spitzoid melanomas (which are malignant), and “atypical Spitz tumor” (a group of tumors whose biologic behavior cannot be accurately predicted on the basis of their histopathologic features).
At present there is no single marker or combination of markers that distinguishes an atypical Spitz tumor from spitzoid melanoma and diagnostic decisions must be made on the basis of assessments (e.g., comparative genomic hybridization, fluorescent in situ hybridization, and gene expression profiling) that are not definitive.
Immunotherapeutic agents for treatment of melanoma:
Yervoy (ipilimumab, targeted at cytotoxic T-lymphocyte-associated protein 4) and Opdivo (nivolumab, targeted at human cell surface receptor programmed death-1) have changed the landscape for treatment of melanoma. You might consider Opdivo as monotherapy should be the first choice for most patients and that addition of Yervoy should be reserved for later line switches or combination therapy due to its greater toxicity.
Long-term follow-up has indicated that Yervoy treatment results in long-term survival in about 20% of patients and it is yet to be determined whether other immune system-directed or other targeted therapies with superior short-term responses have such sustained efficacy.