RESUMEN
Lacrimal sac tumor is a rare tumor, for which we do not know the exact incidence. Malignant tumors account for 70% of all cases. Epithelial tumors are the most common pathological type and squamous cell carcinoma is the most common of these, a transitional cell carcinoma is rare and has a poor prognosis. The authors report a rare case of transitional cell carcinoma of the lacrimal sac. A 57-year-old woman had tearing on her right eye. The pre-operative diagnosis was possible nasolacrimal duct obstruction with signs of dacryocele. Intraoperatively the authors found a lacrimal mass and a frozen section showed squamous papilloma with dysplasia. The tumor was completely removed and DCR was done. The subsequent pathological report of the right lacrimal sac was papillary transitional cell carcinoma, so medial maxillectomy and resection of the medial inferior orbit with ethmoidectomy were performed. She received radiation and has been tumor-free for 2 years.