A 72-year-old man comes to the physician because of a 2-month history of fatigue and worsening abdominal pain. During this period, he has also had night sweats and shortness of breath on exertion. Over the past 3 months, he has had a 5.6-kg (12-lb) weight loss. He had a myocardial infarction 3 years ago. He has hypertension, diabetes mellitus, and chronic bronchitis. His medications include insulin, aspirin, lisinopril, and an albuterol inhaler. He has smoked one-half a pack of cigarettes for the past 45 years. Vital signs are within normal limits. The spleen is palpated 6 cm below the left costal margin. Laboratory studies show: pancytopenia. Bone marrow aspiration is attempted but yields no marrow, and a bone marrow biopsy is subsequently performed. Which of the following findings is most likely to be observed in this patient's bone marrow?

Question

A 72-year-old man comes to the physician because of a 2-month history of fatigue and worsening abdominal pain. During this period, he has also had night sweats and shortness of breath on exertion. Over the past 3 months, he has had a 5.6-kg (12-lb) weight loss. He had a myocardial infarction 3 years ago. He has hypertension, diabetes mellitus, and chronic bronchitis. His medications include insulin, aspirin, lisinopril, and an albuterol inhaler. He has smoked one-half a pack of cigarettes for the past 45 years. Vital signs are within normal limits. The spleen is palpated 6 cm below the left costal margin. Laboratory studies show: pancytopenia. Bone marrow aspiration is attempted but yields no marrow, and a bone marrow biopsy is subsequently performed.  Which of the following findings is most likely to be observed in this patient's bone marrow?

Quizplus · Accepted Answer

Eductional Objective: Primary myelofibrosis is a myeloproliferative disorder associated with the clonal expansion of megakaryocytes.  Bone marrow fibrosis accounts for most of the major manifestations, including hepatosplenomegaly, cytopenias, and blood smear evidence of dacrocytes.  Bone marrow aspiration is usually dry, but bone marrow biopsy will show marked fibrosis with occasional clusters of atypical megakaryocytes.

A 72-Year-Old Man Comes to the Physician Because of a 2-Month