[A case report of isolated marginal zone B cell lymphoma originating from the parapharyngeal space].

This is a case report of isolated marginal zone B cell lymphoma originating from the parapharyngeal space and reaching up to the side of skull base. There are no obvious clinical symptoms of the marginal zone B cell lymphoma originating in the parapharyngeal space, the imaging examination of which showed slightly blurred edge mass shadow with heterogeneous textures and no specificity. The pathological examination revealed a large number of lymphocyte proliferation, which was not specific yet. Immunohistochemistry may show the tumor was monoclonal and positive to CD20 and CD79a positive. Marginal zone B cell lymphoma originating in the parapharyngeal space is a rare tumor with no specific clinical symptoms or early signs, and is easily misdiagnosed. The diagnosis should be confirmed based on pathological and immunohistochemical examination, and the tumor can be treated by surgery combined with chemotherapy.