Spontaneous regression of bilateral conjunctival extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue.

We report the case of a patient who showed spontaneous regression of bilateral conjunctival extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). A 72-year-old man underwent excisional biopsy for salmon-pink lesions involving the whole circumference of the conjunctiva in the right eye and the lower fornix in the left eye. Histopathology and immunohistochemistry showed MALT lymphoma with immunoglobulin kappa monotype shared by the lesions in both eyes. Because the patient had recurrent pulmonary tuberculosis, radiation initially planned for the large residual lesion in the right eye was postponed. Over two years, including 6 mon with anti-tuberculous treatment, the large lesion in the right eye showed spontaneous regression. The spontaneous regression of conjunctival MALT lymphoma observed in this patient suggests that following excisional biopsy for histopathological diagnosis, observation is a treatment option.