Histopathologic Observations of Eyes in Exenterated Orbits After Neoadjuvant Intra-Arterial Cytoreductive Chemotherapy for Adenoid Cystic Carcinoma of the Lacrimal Gland

Purpose: To assess whether exenteration specimens obtained after neoadjuvant intra-arterial cytoreductive chemotherapy (IACC) for adenoid cystic carcinoma of the lacrimal gland demonstrate significant ocular histopathologic alterations that might preclude future pursuit of globe-preserving therapy. Methods: Retrospective histopathologic analysis of globes in IACC-treated exenteration specimens among the same cohort of patients whose survival outcomes have been reported. Results: Twenty patients had specimens available. Nineteen globes revealed no abnormalities of the iris, ciliary body, lens, retinal pigment epithelium, choroid, or chorioretinal vasculature. Eighteen globes showed no optic nerve abnormalities. One globe from a patient who refused exenteration until adenoid cystic carcinoma recurrence supervened demonstrated optic nerve edema with a peripapillary hemorrhage and cotton wool spot, as well as hemorrhage and necrosis within an extraocular muscle. Eighteen globes showed no retinal abnormalities attributable to intra-arterial chemotherapy. Three globes showed incidental retinal findings: 2 globes contained 1 to 2 small peripheral retinal hemorrhages and 1 had a pigmented retinal hole. Seven demonstrated mild, chronic extraocular muscle inflammation, and 13 had unremarkable musculature. The single patient who received IACC via the internal carotid rather than the external carotid artery developed ophthalmic artery occlusion with orbital apex syndrome prior to exenteration, and diffuse necrosis and hemorrhage were evident histopathologically. Conclusions: Neoadjuvant IACC does not cause significant histopathologic damage to key ocular structures or compromise visual function in patients receiving intra-arterial chemotherapy through the external carotid artery. However, delivering chemotherapy through the internal carotid artery may result in visually significant thrombotic vascular events. The generally benign histopathological findings in these exenteration specimens support the concept of IACC delivery through the external carotid system as the cornerstone of a future globe-preserving strategy for lacrimal gland adenoid cystic carcinoma.