A 65-year-old man comes to the physician because of several-month history of progressive fatigue and abdominal pain. The patient has not seen a physician for many years. He does not use tobacco, alcohol, or illicit drugs. Physical examination shows pale mucous membranes and splenomegaly. Hemoglobin concentration is 9.1 g/dL and leukocyte count is 3,400/mm3. Peripheral blood smear shows nucleated red blood cells and teardrop poikilocytosis. Bone marrow aspiration is attempted but yields no marrow. Which of the following histopathological features is most likely to be present in this patient's spleen?

Question

A 65-year-old man comes to the physician because of several-month history of progressive fatigue and abdominal pain. The patient has not seen a physician for many years. He does not use tobacco, alcohol, or illicit drugs. Physical examination shows pale mucous membranes and splenomegaly. Hemoglobin concentration is 9.1 g/dL and leukocyte count is 3,400/mm3. Peripheral blood smear shows nucleated red blood cells and teardrop poikilocytosis. Bone marrow aspiration is attempted but yields no marrow.  Which of the following histopathological features is most likely to be present in this patient's spleen?

Quizplus · Accepted Answer

Eductional Objective: Primary myelofibrosis is a chronic myeloproliferative disorder associated with bone marrow fibrosis. Extramedullary hematopoiesis leads to marked expansion of the splenic red pulp with hematopoietic progenitor cells, resulting in massive splenomegaly. Patients also usually have hepatomegaly, cytopenias, and peripheral smear abnormalities (eg, dacrocytes, nucleated red cells, immature granulocytes).

A 65-Year-Old Man Comes to the Physician Because of Several-Month