[Six cases of nevus oligemicus].

Hamartoma or nevus oligemicus is an uncommon lesion that is characterized by selective vasoconstriction of the deep dermal vascular plexus with respect to the superficial one and whose cause has not been clearly established. This selective vasoconstriction gives rise to fixed, acquired, and asymptomatic lesions in the form of livid, erythematous macules that are typically cold to touch compared with surrounding skin. We report the cases of 6 young men with lesions clinically compatible with nevus oligemicus on the abdomen and flanks. Measurement of the surface temperature of the lesion revealed a decrease of up to 2.5 degrees C with respect to healthy surrounding skin and allowed a definitive diagnosis to be made. We describe the additional studies undertaken, the differential diagnosis, and the possible etiologic agents, and discuss the cases reported in the literature to date. In our opinion, nevus oligemicus is an underdiagnosed lesion that is much more common than has been reported in the literature.