Primary adenocarcinoma of the lacrimal sac with 5-year recurrence-free survival after radiation therapy alone: a case report.

Lacrimal sac tumors are rare, with approximately 800 cases reported worldwide; primary adenocarcinoma of the lacrimal sac is particularly rare. Although there is no established treatment strategy, surgical removal is generally performed. However, complete removal often requires extensive resection, including orbital exenteration and lateral rhinoplasty, which is highly invasive and creates significant cosmetic issues. Here, we report our experience with a 72-year-old woman with primary adenocarcinoma of the lacrimal sac with ethmoid bone invasion. She refused surgery and was treated with radiation therapy alone, totaling 70 Gy in 35 fractions. This is the first report of a patient with primary adenocarcinoma of the lacrimal sac who survived for 5 years without recurrence after radiation therapy alone. She experienced late radiation-related complications: the affected eye developed grade-3 retinopathy according to the common terminology criteria for adverse events, version 5.0, and secondary neovascular glaucoma. Cataract and vitreous surgery with retinal photocoagulation were performed. Her cosmetic appearance was maintained after all treatments were completed. Radiation therapy may be an effective treatment for primary adenocarcinoma of the lacrimal sac for patients who either refuse surgery or in whom surgery is not feasible.