Dermoid cysts masquerading as pilonidal sinus disease

Abstract

BACKGROUND: Dermoid cysts (DC) are benign cystic tumors formed because of impaired embryogenesis processes when ectodermal rudiments are immersed in tissues and organs along the lines of their embryonic fusion. DC is most often localized in the head and neck (84%). Rarer localizations areas are as follows: 1) ovaries; 2) retroperitoneal space; 3) mediastinum; 4) pancreas and spleen; 5) spinal canal. In case of retroperitoneal localization of DC, the presacral location occurs more often, then location in soft tissues of the sacrococcygeal region. Moreover, the clinical pattern may be similar to that of pilonidal disease, which may cause difficulties in diagnosis at the preoperative diagnostics and further determination of the surgical techniques. CLINICAL CASES DESCRIPTION: In the Clinic of colorectal and minimally invasive surgery, two clinical cases of dermoid cysts masquerading as pilonidal sinus disease were encountered. In both cases, Bascom II surgery was performed. Macroscopic examination of the specimens revealed pathognomonic signs of dermoid cysts: a hair growth site on the epithelial lining of the cyst in the first case and the presence of sebum in the cyst cavity in the second case. The early postoperative period in both patients proceeded smoothly, and no data were obtained for recurrence in the 6- and 18-month follow-up period. CONCLUSION: Because of the similar clinical picture of pilonidal cysts and DC of the sacrococcygeal region, differential diagnosis is crucial. A wide range of minimally invasive methods are available for treating pilonidal disease; however, they are not appropriate for the treatment of DC. At present, the only radical method of treating DCs of the sacrococcygeal region is excision of the cyst without rupturing the capsule to prevent disease recurrence.