In a report by Neri et al,7 multiple bright yellow dots were noted on dermoscopy in 2 children with SN. The investigators concluded that this characteristic feature, which was thought to represent the sebaceous glands, can be useful in differentiating SN from aplasia cutis congenita in early infancy, but no histologic analyses were performed.7 In our patient, we identified 3 different dermoscopic features that correlated with histologic findings. Comedolike openings correlated with the accumulated keratin (ie, keratotic plugs) inside dilated sebaceous gland ducts directly connected to the epidermis. The brownish-yellow color of these openings observed on dermoscopy may be due to the oxidation of kerat-inous material, such as those in seborrheic keratosis lesions (Figure 3). We also noted bright yellow dots similar to those reported by Neri et al7; however, histologic analysis in our patient showed these dots more closely correlated with keratotic cysts similar to milialike structures seen in acanthotic seborrheic keratosis. The material remained lightly colored because no oxidation process had occurred (Figure 4). The third structure found on dermoscopy in our patient was multiple whitish structures that were irregular in shape and size. According to our comparison of superficial horizontal histology slides with dermoscopy images, we hypothesized this finding was the result of epidermal papillomatosis over a dermis filled with enlarged sebaceous glands (Figure 5). This finding was likely absent in the cases previously reported by Neri et al7 because epidermal and glandular changes occur later in the evolution of SN and the patients in these cases were younger than 4 months old.
Figure 3. Histologic image of a comedolike opening correlating with a dilated sebaceous duct, filled with keratinous material and communicating directly with the skin surface (periodic acid–Schiff, original magnification ×40).
Figure 4. Histologic image of a comedolike opening and milialike cyst (H&E, original magnification ×40).
Figure 5. Horizontal sectioning at a superficial level allows matching of dermoscopic findings (periodic acid–Schiff, original magnification ×40).
Our correlation of dermoscopic features with histology findings in an 18-year-old woman with an irritated SN highlights the need for more studies needed in order to establish the prevalence of certain dermoscopic findings in this setting, particularly considering the important morphological changes that occur in these lesions as patients age as well as the histological variation among different hamartomas. Over the last decade, dermoscopy has proven to be a useful tool in the diagnosis of various hair and scalp diseases.8 Histologic correlation of dermoscopy findings is essential for more precise understanding of this new imaging technique and should be conducted whenever possible.