Congenital fistulas of the lacrimal sac.

Four patients with congenital lacrimal sac fistulas are presented. All cases were unilateral and not associated with an occluded nasolacrimal duct. In three cases, the fistula and surrounding skin were surgically removed. The fourth case required no treatment. Microscopic examination revealed that the fistulas were lined with stratified, squamous epithelium with or without keratosis, suggesting that they may have developed as outgrowths from the sac or common canaliculus.