Surgical management of perineal masses in patients with anorectal malformations.

BACKGROUND: The aim of this study was to review the outcome of surgical management of various types of perineal masses encountered in patients with anorectal malformations (ARM).
METHODS: Retrospective review from 2 large pediatric anorectal referral centers.
RESULTS: Twenty-two patients with a perineal mass were identified in more than 2000 patients treated for an ARM over a 15-year period. The 22 patients (4 men) represented all levels of severity of ARMs. The lesions were of 3 types: lipomas (n = 10), vascular anomalies (n = 4), and hamartomas/choristomas (n = 8). The lipomas were carefully removed from between the muscle fibers during the posterior sagittal anorectoplasty. The vascular anomalies (3 of 4 were hemangiomas) underwent magnetic resonance imaging preoperatively, but none were found to invade deeply and all were excised at the time of the posterior sagittal anorectoplasty. The hamartomas/choristomas all occurred in women, and 50% arose as a pedunculated mass from the vulva. The lesions contained tissues such as glia, osteoid, nephrogenic rests, and endocervical-type mucosa. One was initially misinterpreted as a teratoma, prompting a wider excision. This and all subsequent patients have been correctly diagnosed pathologically as having either hamartomas or choristomas, which were not widely excised. Follow-up ranges from 5 months to 12 years. Six of the 10 lipoma patients are continent. One vascular anomaly was re-excised and there was minor wound separation in another. None of the hamartoma/choristoma lesions recurred.
CONCLUSION: The presence of unusual perineal masses can add to the complexity of ARMs; however, most of these lesions can be carefully excised with preservation of the muscle complex and ultimate continence. Hamartomatous lesions can be mistaken for teratomas but do not require aggressive excision with clear margins.