[Retrorectal cyst hamartoma: report of a pediatric case]

The retrorectal hamartoma cyst or retrorectal cyst is an uncommon congenital lesion. We present the case of a 7 days-old girl with a retrorectal tumor diagnosed by ultrasound during pregnancy. The histological examination was a cyst lined by squamous and urotelial typical epithelium and a double layer of smooth muscle. The treatment of choice is the complete excision of the lesion, as local recurrences or a malignant transformation have been observed.