An Analysis of Conjunctival Map Biopsies in Sebaceous Carcinoma

Purpose: To evaluate the need for standardized conjunctival map biopsies in periocular sebaceous carcinoma and to formulate recommendations regarding map biopsy number, location, size, and utility based on analysis of biopsy locations, results, and outcomes. Methods: Retrospective consecutive series of patients with sebaceous carcinoma treated at a tertiary care hospital from 1988 to 2013. Main outcome measures included conjunctival biopsy locations, number, size, and pathology. Results: A diffuse eyelid pattern was evident on presentation in 28/51 patients (54.9%) versus a solitary eyelid nodule in 23/51 (45.1%). Forty-five patients underwent a total of 429 conjunctival biopsies. The conjunctiva was negative in 277 specimens (64.6%), positive in 121 (28.2%), suspicious in 26 (6.1%), and nondiagnostic in 5 (1.2%). Intraepithelial conjunctival involvement was present in 36 patients (70.6%) of whom 23 (63.9%) presented with a diffuse eyelid appearance. There was no statistically significant correlation between primary tumor location and sites of positive biopsies or biopsy size. The pattern at presentation and location of primary tumor did not correlate with biopsy results. Clinical assessment regarding conjunctival involvement was incorrect in 10 of 23 patients (43.5%) with a solitary nodule. Despite primary tumor resection with clear margins confirmed on pathology, 5 of 45 (11%) patients had locally recurrent sebaceous carcinoma. Conclusions: Conjunctival biopsy size does not correlate with the presence of tumor in the biopsy. Primary tumor location and pattern of tumor at presentation do not correlate with conjunctival biopsy results. Irrespective of the clinical tumor features, standardized conjunctival map biopsies are essential in staging periocular sebaceous carcinoma.