Eight Patients With Pilonidal Carcinoma in One Decade—Is the Incidence Rising?

Introduction: Carcinoma secondary to pilonidal disease is very rare with fewer than 130 reported cases so far. It is presumed that underreporting and underpublishing contribute to the low reported incidence. Methods: A post was published on a closed Facebook group with about 30,000 Syrian doctors asking if anyone had ever seen a patient with pilonidal carcinoma before. The patients' data were collected retrospectively from the treating physicians. Results: Between 2010 and 2019, we identified eight patients with pilonidal carcinoma. All patients were males with a mean age of 55.5 years. The mean interval between diagnosis of pilonidal disease and diagnosis of carcinoma was 6.9 years. A growing ulcer on the background of a pilonidal sinus disease was the presenting complaint in 50% of cases. Three patients were lost from follow-up after the diagnosis due to referral. All other five patients underwent surgical resection and three of them received postoperative chemoradiation. Four patients were followed for six months or longer: two died of metastases, one survived after recurrence and re-excision, and one survived with no recurrence. Conclusion: This paper presents the largest cohort of pilonidal carcinoma so far and the first that describes the disease in the Syrian population. Due to underreporting, the real incidence of pilonidal carcinoma exceeds what is reported so far in the literature.