Histopathological Features of Nevus Sebaceous and Superimposed Skin Tumors.

Introduction: Nevus sebaceous (NS) is a rare congenital hamartoma that may cause some concerns for parents. Benign skin tumors can develop in NS, although malignant transformations have occasionally been documented. This study aimed to investigate the histopathological characteristics of NS lesions in relation to sex, age, location, type, and any associated superimposed tumors. Methods: This retrospective cross-sectional study was conducted on the histopathologic reports of 60 patients with NS who were referred to our center between 2010 and 2022. Information, including sex, age, location of the lesion, and histopathological features of the NS lesion, was recorded. Results: The mean age of the patients was 24.52 ± 12.19 years, and 65.0% of the patients (39 cases) were men. Most of the lesions were observed on the scalp and face. Benign and malignant neoplasms were observed in 5% and 10% of patients, respectively. All the cases of malignant tumors (six cases) were identified as basal cell carcinoma, and three cases were benign tumors of syringocystadenoma papilliferum. Demodex infestation and apocrine gland dilatation were observed in 56.7% and 23.3% of patients, respectively. Benign neoplasms were significantly more frequent in women (p=0.039). In addition, malignant neoplasms were significantly more prevalent among patients aged ≥ 25 years (p=0.001). The frequencies of acanthosis and focal parakeratosis were higher in the scalp, and sebaceous hyperplasia was more common in the face (p < 0.05). Conclusion: Our study revealed that malignant tumors were more common than benign lesions in patients with NS. Benign neoplasms were more frequent in women. Malignant neoplasms were detected in patients aged more than 25 years.