Atypical presentation of punctal keratin cyst: an underdiagnosed entity

Punctal keratin cyst (PKC) is a rare disorder believed to be due to ectasia of the vertical canaliculus. The etiopathogenesis of this disorder is very poorly understood due to the paucity of literature. To the best of authors' knowledge, only two cases of punctal keratin cyst have been described earlier, which presented as cystic lesions. The authors report four cases of punctal keratin cyst which differ in clinical presentation and also describe the anterior segment ocular tomography features, which aids in recognition and diagnosis of this rare disorder. The key message of the article is that lack of a defined cyst on clinical examination and optical coherence tomography (OCT) cannot rule out the presence of a PKC. A combination of clinical, radiology, and histopathology are confirmative of the diagnosis. Once diagnosed, the subsequent outcomes with membranotomy and keratin curettage are excellent.