Objective: To illustrate a newly recognized histopathologic change in a patient with canalicular obstruction after weekly administration of 5-fluorouracil for colon cancer.
Design: Interventional case report.
Methods: A full-thickness section of canaliculus was obtained during surgical repair.
Main outcome measure: Histopathologic changes in the specimen.
Results: The prominent histologic feature of the canalicular specimen was severe squamous metaplasia with narrowing of the lumen.
Conclusion: Canalicular obstruction may follow systemic use of 5-fluorouracil due to squamous metaplasia.