1. The images for this case are of a spleen from a 70 year old man with a history of “leukemia.” A splenectomy was performed for symptoms. Flow cytometry show dim positivity for CD20 and kappa light chains. In addition, CD5 and CD23 were positive and CD10 was negative. Based on these findings, the best diagnosis is:

2. The images for this case are from a spleen removed for “symptoms.” It weighed 1,000 grams and had multiple small white nodules throughout the parenchyma. Special stains were positive for CD20 but negative for CD5, CD43 and CD10. Based on these findings, the best diagnosis is:

3. A 24 y/o male with a history of short stature and renal failure (s/p renal transplant) presented with multiple splenic abscesses. A splenectomy was performed. Representative sections from the spleen are shown for this case. Based on the clinical history and morphologic findings, the best diagnosis is:

4. These images are from a 300 gram spleen, which was noted to have multiple blood filled nodules. The cells of interest were positive for CD68 and CD31 but negative for CD34. Based on these findings, the best diagnosis is:

5. Multiple vascular lesions were found in a 70 year old male with no other significant past medical history. No other lesions in other organ were found. A splenectomy was performed, which showed multiple blood filled vascular areas. Representative images from the spleen are shown for this case. Based on the findings, the best diagnosis is:

6. During an operation, the spleen was noted to have multiple masses. Representative sections from these areas are show in the images for this case. Based on the morphologic findings, the best diagnosis is:

7. A calcified lesion was found incidentally in a 20 y/o. At surgery it was found to originate from the 400 gram spleen. Based on the morphologic findings, the best diagnosis is:

8. A patient is diagnosed with CLL/SLL. Which of the following are associated with a poor prognosis:

9. A 45 y/o male presents to his physician with early satiety. Physical examination was significant for an enlarged spleen. A CBC & bone marrow examination was performed at an outside institution that was significant only for a monocytopenia. No flow cytometry was performed. The patient now undergoes a splenectomy due to continued symptoms. Representative histologic sections of the 500 gram spleen are shown on the website. Flow cytometry is performed and shows a monoclonal kappa population that expresses CD103, CD11b, CD25, and CD20. Based on these findings, the best diagnosis is:

10. Examination of a spleen shows dilated sinuses containing histiocytic appearing cells with occasional emperipoesis. Lympocytes are mixed in, and plasma cells are noted to cuff around small vessels. You suspect a diagnosis, which should have which of the following staining characteristics: