[Lymphoma revealed by isolated obliquus inferior muscle involvement in exophthalmia]

Orbital lymphomas account for 4% of nontraumatic orbital disorders. We report the case of a 54-year-old patient who presented with binocular diplopia associated with right exophthalmia with an isolated obliquus inferior localization. This lymphomatous localization was unexpected, as lymphomas are described more often in the rectus superior and inferior muscles. Pathological examination found a low-grade non-Hodgkin's MALT lymphoma. This case is the basis of a review of the various diagnoses and the necessity of a biopsy prior to surgical tumor ablation that may damage an oculomotor muscle. Treatment should be medical: first-intention surgery would have abolished obliquus inferior function.