Dysplastic vulvar nevi.

Of several pigmented vulvar lesions, the dysplastic nevus, a know precursor of malignant melanoma, has been described only twice. Focusing on pigmented vulvar lesions, 18 were excised among approximately 500 unselected parturients. Three lesions showed clinical and histologic characteristics of a dysplastic nevus. The patients with a dysplastic vulvar nevus were 21, 27, and 30 years old, respectively; all three had multiple torso and limb nevi and two had anamnestic features of the dysplastic nevus syndrome. Only one was aware of her vulvar lesion. All dysplastic nevi were brown or black and were larger than 5 mm in diameter. Our cases suggest that dysplastic vulvar nevi may be more frequent than previously thought. We suggest that the puerperium is a suitable time for a definite histologic diagnosis of large-size lesions with variegated pigmentary patterns and irregular borders that occur on the vulvar skin. Likewise, in other patients with suspected dysplastic vulvar nevi, excisional biopsy is recommended.