Secondary Tumors Arising from Nevus Sebaceus: A Multicenter Collaborative Study and Literature Review.

Background: Although various benign and malignant tumors can arise in nevus sebaceus (NS), the demographic and clinicopathological features of the secondary tumors vary among different published reports. The aim of this study was to obtain a better understanding of the features of tumors secondary to NS.

Methods: A multicenter study was performed by reviewing patients diagnosed with NS from the Dermatology Department of the First Affiliated Hospital of Chongqing Medical University and Qijiang Hospital of the First Affiliated Hospital of Chongqing Medical University from 2010 to 2022. A literature review of case series of secondary tumors arising in NS was also conducted.

Results: We retrospectively analyzed the literature on tumors secondary to NS published since 2000, with a total of 443 cases, and carefully studied cases of tumors arising in NS from multiple centers since 2010, with a total of 54 cases. There were 497 cases in this study; 90.3% were benign tumors (n = 449), and the rest were malignant tumors (9.7%, n = 48). Syringocystadenoma papilliferum was the most common benign tumor, followed by trichoblastoma and trichilemmoma. Basal cell carcinoma was the most common secondary malignant tumor to NS, followed by squamous cell carcinoma. Two of these cases developed metastasis. Secondary malignancies developed at an earlier age in Caucasians than in Hispanics and Asians.

Conclusion: The present study is the largest analysis of tumors secondary to NS. Racial differences were seen in secondary tumors to NS and may contribute to healthcare disparities between races.