Clinicopathological study of 13 cases of squamous cell carcinoma complicating hidradenitis suppurativa.

Background: To the best of our knowledge, only 52 cases of squamous cell carcinoma (SCC) complicating hidradenitis suppurativa (HS) have been reported since 1958. We describe 13 new cases.
Methods: We propose a clinical and histological analysis of our cases. We include these results in a review of previously reported cases to analyze a total of 65 patients. In our series of 13 cases, we also investigate the presence of human papillomavirus (HPV) in tumor samples, by polymerase chain reaction (PCR) on paraffin-embedded material.
Results: Malignant transformation affects mainly men with a long-term history of genitoanal HS. Although our cases were 7 well-differentiated carcinomas and 6 verrucous carcinomas, lymphatic and visceral metastasis occurred in 2 and 3 cases, respectively. With PCR, we demonstrated presence of HPV in genitoanal tumoral lesions, principally HPV-16.
Conclusion: SCC complicating HS evolves poorly, despite a good histological prognosis. Our results sustain the implication of HPV in the malignant transformation of HS.