LAUSR

A 35-year-old woman presented with acute left eye vision loss. 12 years earlier, she was treated for AML with induction chemotherapy and matched unrelated donor allogenic stem cell transplantation, complicated by persistent GVHD of lungs and oral mucosa and eyes. 6 years ago, she developed extramedullary relapse of the AML involving ovary and stomach, attaining a remission after treatment with standard induction and consolidation chemotherapy. At her current presentation, she was initially diagnosed with optic neuritis based on ophthalmic exam. MRI showed T1 signal enhancement along the left optic nerve (Panel A), interpreted as representing either optic neuritis or optic nerve involvement of recurrent AML. CSF analysis revealed 81 WBCs/μl with numerous myeloblasts with large nuclei and fine chromatin and Auer rods (Panel B, 100× objective). Flow cytometry demonstrated the cells to be CD34 positive, CD45 dim, HLA-DR positive, CD33 positive, CD36 negative, CD64 partial positive, CD14 negative, and CD123 dim, consistent with a diagnosis of AML. Further characterization, including genetic studies, could not be performed because of paucity of cells in the CSF specimen. CBC was normal. Bone-marrow aspiration and biopsy revealed normal hematopoiesis with complete donor engraftment and no evidence of leukemic relapse. She was treated with localized radiation therapy to her left optic nerve and intrathecal cytarabine and methotrexate with improvement of her vision and complete cytologic response. This case illustrates the finding of blasts with Auer rods in the CSF, and highlights the importance of CSF analysis in the neurological evaluation of patients with a prior diagnosis of AML (Fig. 1).