A 54-year-old previously healthy man comes to the clinic after 2 months of progressive, generalized weakness and easy fatigability. He also has abdominal discomfort and early satiety. The patient works as a security advisor and has not traveled recently. He is afebrile and other vitals signs are normal. On examination, he has pallor, abdominal distension, and massive splenomegaly with the spleen tip crossing the midline. No peripheral lymphadenopathy is present. Peripheral blood cell count shows pancytopenia. Bone marrow aspiration is attempted, but no marrow can be aspirated. Which of the following findings is most likely to be seen in this patient?

Question

A 54-year-old previously healthy man comes to the clinic after 2 months of progressive, generalized weakness and easy fatigability.  He also has abdominal discomfort and early satiety.  The patient works as a security advisor and has not traveled recently.  He is afebrile and other vitals signs are normal.  On examination, he has pallor, abdominal distension, and massive splenomegaly with the spleen tip crossing the midline.  No peripheral lymphadenopathy is present.  Peripheral blood cell count shows pancytopenia.  Bone marrow aspiration is attempted, but no marrow can be aspirated.  Which of the following findings is most likely to be seen in this patient?

Quizplus · Accepted Answer

Lymphocytes with cytoplasmic projections are seen in hairy cell leukemia, an indolent B-cell neoplasm (predominantly diagnosed in middle-aged men) that infiltrates the bone marrow and reticuloendothelial system. Bone marrow infiltration and cytokine production cause fibrosis and bone marrow failure, resulting in pancytopenia. A bone marrow aspirate is usually unsuccessful ("dry tap"). Splenic red pulp infiltration can result in massive splenomegaly (ie, crossing midline or extending into left lower quadrant). Common manifestations include left upper quadrant pain, fatigue, weakness, fever, and recurrent infections. The diagnosis is made by bone marrow biopsy and flow cytometry, which has replaced tartrate-resistant acid phosphatase (TRAP) activity testing. (Choice A) Intraerythrocyte ring forms are seen in malaria. This patient has no travel history and no fevers to suggest malaria. (Choice C) Myeloid cells with azurophilic rodlike granules (Auer rods) can be found in acute myeloid leukemias, which do not typically cause hepatosplenomegaly. (Choice D) Heterophile antibodies are found in most patients with Epstein-Barr virus-induced infectious mononucleosis, which commonly presents in young adults with low-grade fever, pharyngitis, and cervical lymphadenopathy. Mild hepatosplenomegaly may be present. (Choice E) Ringed sideroblasts are abnormal erythrocyte precursors found in myelodysplastic syndrome (MDS) and characterized by mitochondrial iron accumulation surrounding the nucleus. Patients with MDS typically have petechiae, weakness, and recurrent infections; splenomegaly is uncommon. Educational objective: Hairy cell leukemia is an indolent B-cell neoplasm predominantly found in middle-aged men and characterized by bone marrow failure and infiltration into the reticuloendothelial system, causing massive splenomegaly. Other typical features include a "dry tap" (unsuccessful bone marrow aspiration) and the presence of lymphocytes with cytoplasmic projections. __________ References: How I treat hairy cell leukemia. (http://www.ncbi.nlm.nih.gov/pubmed/19843881) Hairy cell leukemia: short review, today's recommendations and outlook. (http://www.ncbi.nlm.nih.gov/pubmed/24531447)

A 54-Year-Old Previously Healthy Man Comes to the Clinic After