Six-Year Remission With No Relapse After Four-Time Weekly Rituximab Only for Bilateral Ocular Adnexal Follicular Lymphoma

Follicular lymphoma mostly takes an indolent course, and thus, observation with watchful waiting is a main therapeutic strategy. Recent long-term studies suggest earlier treatment with rituximab monotherapy may benefit patients by delaying the need for treatment in the later phase of exacerbation. In this study, we reported a patient with bilateral orbital follicular lymphoma who received four-time weekly rituximab monotherapy as an induction therapy only and maintained the remission for 5 years with no treatment. The patient was a 51-year-old woman who developed a right upper orbital mass and was diagnosed with follicular lymphoma grade 1 by the excisional biopsy. Two years later, at the age of 53 years, she developed a left lacrimal gland mass and underwent excision. The pathological diagnosis was follicular lymphoma grade 1. She did not have any other systemic lesions by fluorodeoxyglucose positron emission tomography. At the age of 54 years, she developed a new mass on the nasal side of the right orbit and underwent weekly rituximab monotherapy (375 mg/m2) four times a month, leading to the reduction of the mass in 3 months. Two high uptake sites on the temporal and nasal side of the right superior orbit by fluorodeoxyglucose positron emission tomography disappeared one year later at the age of 55 years. She was followed with no treatment for 6 years until the age of 60 years at the latest visit. In case of a local orbital relapse, local radiotherapy would be the standard, but rituximab monotherapy as an induction therapy only was chosen in the present patient. Rituximab monotherapy in place of local radiotherapy would be a treatment option for orbital follicular lymphoma.