[Double vision and a wrong track]

A 72-year-old woman presented to our emergency centre with acute horizontal diplopia. Neurological examination revealed an isolated abducens nerve paresis on the left. Hilar enlargement seen on the chest x-ray and an elevated serum ACE level led us to suspect sarcoidosis, but the patient declined further evaluation. In the following days, her visual acuity decreased steadily, and she developed cervicothoracic pain, left sided ptosis, weakness of the right arm, and general asthenia. When she was readmitted as an emergency case, neurological examination revealed decreased visual acuity, external ophthalmoplegia and ptosis on the left and a C8 radicular lesion on the right. Imaging studies showed multilocular lesions, e. g. in the left orbital space, spinal epidural manifestations and lymphoma nodular involvement, including retroperitoneally. Laboratory chemistry showed elevated serum levels of ACE, sIL2 receptor and an elevated CD4 / CD8 ratio while bronchoalveolar lavage indicated lymphocytic alveolitis. The biopsy performed under the left M. masseter with a presumptive diagnosis of sarcoidosis, showed a diffuse large-cell B-cell lymphoma. We initiated immuno-chemotherapy following the R-CHOP schema with a curative approach. The case shows the lack of specificity of clinical, imaging and laboratory findings and thus underlines the need for histology in the differential diagnosis of sarcoidosis.