A 48-year-old man has experienced increasing malaise and difficulty concentrating at work for the past 6 months. On physical examination he has splenomegaly but no lymphadenopathy. He is afebrile. Laboratory studies show Hgb 12.0 g/dL, Hct 35.8%, MCV 92 fL, platelet count 390,000/uL, and WBC count 190,000/uL with differential count 73 segs, 12 bands, 6 metamyelocytes, 2 myelocytes, 2 myeloblasts, and 5 lymphs. The leukocyte alkaline phosphatase (LAP) score is very low. A bone marrow biopsy is performed. Which of the following microscopic findings is most likely to be found in this biopsy? Atypical cytokeratin positive glands Predominance of adipocytes Numerous mature and immature myeloid cells Sheets of plasma cells Granulomas that have many acid-fast bacilli.

A 48-year-old man has experienced increasing malaise and difficulty concentrating at work for the past 6 months. On physical examination he has splenomegaly but no lymphadenopathy. He is afebrile. Laboratory studies show Hgb 12.0 g/dL, Hct 35.8%, MCV 92 fL, platelet count 390,000/uL, and WBC count 190,000/uL with differential count 73 segs, 12 bands, 6 metamyelocytes, 2 myelocytes, 2 myeloblasts, and 5 lymphs. The leukocyte alkaline phosphatase (LAP) score is very low. A bone marrow biopsy is performed. Which of the following microscopic findings is most likely to be found in this biopsy? Atypical cytokeratin positive glands Predominance of adipocytes Numerous mature and immature myeloid cells Sheets of plasma cells Granulomas that have many acid-fast bacilli.