Track: Clinical Studies

Topic: Neoplasia,Carcinogensis,Tumor Biology

Abstract:

Sebaceous neoplasms, including sebaceous adenoma, sebaceoma and sebaceous carcinoma, have been linked to underlying UV signature mutations, MMR protein deficiency or high-risk HPV infection.

Sebaceous neoplasms are rarely encountered in the genital area, and the aim of this study was to analyze their clinicopathologic features, their association with HPV infection and their MMR protein status. Ethical approval was obtained, H&E-stained sections and immunohistochemistry for p16, p53, MSH2, MSH6, MLH1 and PMS2 were reviewed, and HPV-ISH was performed. Clinical follow-up was obtained from patient records. Six tumors presented in adulthood (median: 69; range: 48-73 years; M:F=2:1) and were located on the penis, mons pubis and labia majora (median size 1.3 cm). There were four sebaceous carcinomas, one sebaceoma and one sebaceous adenoma. Three of four sebaceous carcinomas showed an overlying in-situ component, were positive for high-risk HPV-ISH, p16 block positive and p53 wildtype. The sebaceous adenoma showed loss of MMR proteins and was associated with Muir-Torre syndrome (MTS) while all remaining tumors were MMR stable, HPV-ISH negative and p16 and p53 wildtype. The patient with MTS died of esophageal adenocarcinoma, all other patients were alive without recurrences (median follow-up: 16 months, range 7-60 months).

In conclusion, the study emphasizes a pathogenetic role of HPV in genital sebaceous carcinoma that typically present with an in situ component.