Agminated atypical (dysplastic) nevi - Case report and review of the literature

Background: Patients with the atypical mole syndrome have multiple dysplast ic nevi that appear to be randomly distributed on certain preferred anatomi cal sites such as the upper back. These dysplastic nevi are thought to be a cquired melanocytic nevi that begin appearing at puberty. To our knowledge, the presence of agminated atypical (dysplastic) nevi has not been reported . Observation: We describe a patient with the atypical mole syndrome who has more than 100 melanocytic nevi, many of which are clinically atypical and o ne of which proved to be a melanoma. Among his many melanocytic nevi is a c luster of approximately 50 nevi that are distributed in an area measuring 5 x3 cm. The histopathologic features of these nevi are consistent with the d iagnosis of "dysplastic nevus.' Conclusions: To our knowledge, agminated atypical (dysplastic) nevi have no t been described previously. The presence of agminated atypical (dysplastic ) nevi in a patient with the atypical mole syndrome can be theorized To ari se because of loss of heterozygosity.