Intraoperative 5-Aminolevulinic Acid Fluorescence in Periocular Sebaceous Carcinoma: A Proof-of-Concept Case Report.

We report a proof-of-concept case demonstrating intraoperative fluorescence of periocular sebaceous carcinoma using 5-aminolevulinic acid (5-ALA). 5-aminolevulinic acid-induced fluorescence has been well established in neurosurgical oncology for high-grade glioma resection and more recently applied to select head and neck malignancies. Given the challenges of visualizing sebaceous carcinoma intraoperatively-particularly due to pagetoid spread and subtle epithelial involvement-we evaluated whether 5-ALA could delineate tumor extent in vivo and correlate with histopathology. An 80-year-old man with a large, biopsy-proven invasive sebaceous carcinoma of the right upper eyelid and conjunctiva underwent planned orbital exenteration with sentinel lymph node biopsy. Preoperative imaging demonstrated extensive periocular disease without retrobulbar invasion or metastatic spread. As part of an investigational protocol, oral 5-ALA (20 mg/kg) was administered 3.5 hours before surgery. Intraoperative blue-light examination revealed distinct fluorescence of the bulbar and tarsal conjunctiva and caruncle that was not appreciable under white light. Histopathologic analysis confirmed sebaceous carcinoma in all fluorescent regions, while nonfluorescent areas were tumor-free. Sentinel lymph nodes did not fluoresce and were negative for metastasis. The patient tolerated 5-ALA without adverse effects. This case demonstrates that 5-ALA fluorescence can identify occult periocular sebaceous carcinoma in vivo and correlate closely with histopathology. These findings support the potential role of 5-ALA as an intraoperative adjunct for tumor mapping and margin assessment in future globe-sparing surgery for periocular malignancies.