Image Description
Involvement of the urinary tract by myeloid sarcoma is rare. There are only isolated reports of cases involving urinary bladder. This image from a bladder biopsy specimen shows diffuse sheets of poorly-differentiated cells with finely dispersed chromatin and punctate nucleoli. Immunohistochemical studies were diagnostic of myeloid sarcoma. The patient was found to have acute myeloid leukemia in the bone marrow.