Conjunctival Pediatric-Type Follicular Lymphoma.

Pediatric-type follicular lymphoma is an uncommon B-cell lymphoma that primarily involves the lymph nodes of the head and neck of children and young adults. Ocular involvement is rare, with only 5 well-documented cases in the literature, all occurring in the conjunctiva. The authors describe a 20-year-old African American man with enlarging bilateral medial conjunctival nodules. Excisional biopsy of the larger left conjunctival lesion, clinically presumed to be pyogenic granuloma, revealed pediatric-type follicular lymphoma composed of expansile follicles with germinal centers containing mitotically active blastoid cells, which coexpressed CD20, CD10, and BCL6 and lacked expression of BCL2. Polymerase chain reaction for immunoglobulin heavy chain rearrangement identified a monoclonal B-cell population. Fluorescence in situ hybridization studies failed to demonstrate BCL2, BCL6, and MALT1 gene rearrangements. Next-generation sequencing revealed a pathogenic MAP2K1 mutation, known to be enriched in pediatric-type follicular lymphoma. This report summarizes the clinical and pathologic diagnostic findings, biologic behavior, and management of conjunctival pediatric-type follicular lymphoma.