Unusual Presentation of Myeloid Sarcoma in a Patient With Usher Syndrome

A 45-year-old woman with Usher syndrome, associated congenital deafness, progressive blindness due to retinitis pigmentosa, and latent autoimmune diabetes presented to the emergency department with malaise, dizziness, and pelvic pain following removal of an intrauterine device. A posterior vaginal wall mass was found on examination. Laboratory values demonstrated anemia, thrombocytopenia, and an elevated white blood cell count, raising concern for infection and potential onset of diabetic ketoacidosis. This prompted a peripheral blood smear review, which showed 60% monocytic blasts. A subsequent vaginal mass biopsy showed a myeloid sarcoma. Molecular studies demonstrated an NPM1mutation in exon 12 without FLT3mutation or internal tandem duplication.While a diagnosis of acute myeloid leukemia with mutated NPM1 was considered, cytogenetics revealed a complex karyotype with evidence of clonal evolution, consistent with acute myeloid leukemia with myelodysplasia-related changes. In addition to an unusual presentation of myeloid sarcoma, this case posed significant questions regarding management and pursuit of hematopoietic stem cell transplantation. Usher syndrome is genetically and clinically heterogeneous. While it is not known to be associated with increased risk of malignancy, mutation of genes associated with Usher syndrome has been identified in acute leukemia. Our case raises the question as to whether potential germline predisposition should be considered in a patient with a previously unassociated congenital syndrome.