Combined Endoscopic and External Dacryocystectomy Surgical Approach for Rare Tumors of the Lacrimal Sac.

Lacrimal sac epithelial tumors are rare and often present with subtle symptoms. We report 2 cases managed with combined external dacryocystectomy and endoscopic endonasal resection. Case 1 involved a 59-year-old female with lacrimal sac inverted papilloma extending into the nasolacrimal duct and inferior meatus. Case 2 involved a 79-year-old male with a chronically draining medial canthal wound and progressive induration after prior cyst excision, ultimately diagnosed as lacrimal sac oncocytoma. In both cases, preoperative imaging and clinical features demonstrated nasolacrimal duct involvement and adjacent anatomic distortion, prompting combined surgery for direct visualization and controlled resection of the lacrimal sac and ductal components. The combined approach allowed safe excision despite ductal expansion and adjacent tissue involvement. A small localized recurrence in case 1 at 11 months was successfully managed with in-office resection. These cases support case-selected multidisciplinary external-endonasal surgery for lacrimal sac tumors with nasolacrimal duct involvement.