Extramedullary myeloid cell tumor of the urinary bladder in a patient with myelodysplastic syndrome.

We report a case of extramedullary myeloid cell tumor of the urinary bladder in an elderly male with a three year history of myelodysplastic syndrome (refractory anemia with excess blasts), noninvasive papillary transitional cell carcinoma of the urinary bladder, and in situ transitional cell carcinoma of the left ureter. Light microscopy demonstrated a poorly differentiated neoplasm composed of medium to large cells with eosinophilic cytoplasm. The tumor cells showed immunohistochemical expression of myeloperoxidase, lysozyme, CD15, CD68 and CD43. Bone marrow examination following cystectomy demonstrated refractory anemia with excess blasts (6-10%) and a normal karyotype. Cytogenetics, approximately 1 year after cystectomy, demonstrated a deletion of the short arm of chromosome number 12. Four years after presentation, the patient succumbed to pulmonary aspergillosis.