An indolent, low-grade B-cell non-Hodgkin lymphoma that arises from the choroid, iris, or ciliary body. It is characterized by the presence of a diffuse infiltrate of small, round lymphocytes. Lymphoid follicles with germinal centers may be present. In the past these tumors were termed ''reactive lymphoid hyperplasia''. Now they are considered low-grade B-cell lymphomas, most commonly extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue. [from
NCI]