Could Extension Into the Lacrimal Gland and Sac Thwart Topical Chemotherapy for Intraepithelial Sebaceous Carcinoma?

Abstract

Purpose: To identify the frequency of intraepithelial (Pagetoid) spread beyond the ocular surface—namely beyond conjunctiva and cornea—in patients undergoing orbital exenteration for advanced periocular Sebaceous carcinoma (SC). Design: A retrospective, noncomparative observational case series. Subjects: Patients undergoing orbital exenteration for biopsy-proven SC, at Moorfields Eye Hospital between 1997 and 2013. Methods: Review of clinical records and histological specimens, with particularly reference to involvement of conjunctiva and the extent of Pagetoid infiltration beyond the examinable ocular surface—here termed “hidden” disease. Main outcome measures: Histological evidence of intraepithelial SC within the lacrimal sac or lacrimal gland. Results: Twenty-nine patients had clinical data and histological specimens adequate for review. Seventeen (59%) did not have a discrete mass (clinically or histologically) and, on clinical examination, were thought to only have extensive intraepithelial carcinoma; foci of microscopic invasion were, however, detected histologically in 11/17 (65%) of these specimens. Moreover, the in situ carcinoma was found to have invaded far in lacrimal gland ductules in 1/17 patients, in the lacrimal sac (in 2 patients; 12%) or in both the gland and sac (in 2 patients); these 5/17 (29%) cases all showed extensive poorly differentiated intraepithelial SC. Of the 12 other patients who had both Pagetoid spread and a clinically evident nodule, 3 had histological evidence of “hidden” disease. Conclusion: Although—due to their being operated in the era prior to the accepted usage of topical therapy for this condition—some of these exenterations might have had particularly advanced in situ SC, over a quarter of patients with periocular SC warranting orbital exenteration show “hidden” intraepithelial tumor within the lacrimal gland and sac. This important finding might significantly reduce the efficacy (particularly in the lacrimal gland) of the various topical therapies used for in situ SC of the ocular surface, and it also emphasizes the importance of excising both the lacrimal gland and sac in all orbital exenterations for this particular tumor.