Ischiorectal fossa lipoma

Introduction: The ischiorectal fossa is a fat-containing space around the anal canal. Primary lesions in this area are rare and can present as cystic or solid, and can be benign or malignant. Ischiorectal lipomas are a rare entity with scarce literature reports, and most if not all of the reports, are described in the adult population. Surgical excision can be difficult due to the complex anatomy of the region and the possibility of injuring the sphincteric mechanisms. The usual approach for localized masses is through a posterior approach. Ischiorectal lipoma in the pediatric population is an uncommon tumor, and proper anatomical knowledge is important for the adequate management of the patient. Case description: A 15-year-old twin female presented to the surgery clinic with gradual onset of enlarging right gluteal mass associated with progressive constipation and dysmenorrhea. The diagnosis of a right ischiorectal fossa lipoma was entertained by Magnetic resonance imaging (MRI). The MRI showed the mass extending inferiorly into the right gluteal fold, causing a distortion of the anal sphincter and the pelvic floor muscles. A posterior sagittal anorectoplasty (PSARP) with excision of the right ischiorectal lipoma was performed. The area involved exhibited a large mass composed of fatty tissue extending cephalad from the genital area and caudally to rectal and ischial spaces. Lipoma was confirmed by the pathology report. After a 6-month follow up, the patient had remained asymptomatic and without evidence of recurrence. Conclusion: Ischio-rectal lipoma is a rare tumor, especially in the pediatric population. A PSARP is the best approach to avoid neurovascular damage, as well as tumor recurrence.