Cogan’s syndrome is a rare disorder characterized by ocular and audiovestibular manifestations in its typical form and caries a wide variety of atypical manifestations. It is considered as an autoimmune disease. We present the first case in the literature of a 67 year old woman with the development of low grade non-Hodgkin lymphoma (NHL) in the mastoid bone in a preexisting history of atypical Cogan’s syndrome. The anatomical development of NHL was to a ‘‘target’’ organ of Cogan’s syndrome, which is the inner ear. | Development of a low grade lymphoma in the mastoid bone in a patient with atypical Cogan’s syndrome: A case report