Rare Case of Non-Keratinizing Squamous Cell Carcinoma in the Lacrimal Sac Treated with Surgery.

: The objective of this study was to present a rare case of non-keratinizing squamous cell carcinoma (SCC) of the lacrimal sac (LS). Neoplasms of the lacrimal drainage system are extremely rare. These lesions are predominantly malignant and are associated with a high mortality rate. A 51-year-old woman was referred to an ophthalmologist with a history of unilateral epiphora, presbyopia, and abnormal eye discharge. Antibiotic therapy was applied and modified later due to persisting symptoms. After five months, edema of the medial left eye angle occurred. A lacrimal sac incision was performed, and a subsequent magnetic resonance imaging (MRI) scan revealed a 2 cm, contrast-enhanced solid tumor. The patient was qualified for dacryocystectomy, which was conducted by the otolaryngology department. Postoperative histopathologic findings indicated the presence of non-keratinizing SCC. During a reoperation, margins were extended, and the surgery was found to be radical. Following the reoperation, no alarming symptoms were observed. However, a follow-up MRI and positron emission tomography (PET) scan six weeks later revealed metastases. Further treatment is being planned. LS tumors are life-threatening conditions that are challenging to diagnose at an early stage. Surgical excision is the preferred treatment option. Imaging studies play an important role in post-operative follow-up because of the possibility of recurrence and metastasis, even after radical surgery.