Sarcoidosis with bone marrow involvement.

427 virus, hepatitis B virus, hepatitis C virus, cyto‐ megalovirus, and Epstein–Barr virus) were ex‐ cluded. Blood and urine cultures were negative. Tuberculosis was excluded. Serum iron and fo‐ lic acid levels were normal, while a moderate vi‐ tamin B12 deficiency was detected (101 pg/ml; normal range, 157–1057 pg/ml). A small propor‐ tion of erythroblasts had dysplastic features on bone marrow (BM) aspiration, which might be consistent with vitamin B12 deficiency; however, an early phase of myelodysplastic syndrome was also considered. Thus, a trephine biopsy was per‐ formed. Considering the results of the BM biop‐ sy, the patient received vitamin B12 injections at a dose of 0.1 mg daily intramuscularly, then once a week for a total of 2 months, but pancytope‐ nia persisted. The biopsy did not reveal any po‐ tential causes of pancytopenia, and no dysplas‐ tic features were demonstrated. Nevertheless, an oval sarcoidal granuloma consisting of epi‐ thelioid histiocytes and multinucleate giant cells was observed in the hematoxylin and eosin stain of the biopsy. The granuloma was sparsely sur‐ rounded by a rim of lymphocytes. Necrosis was not observed (FIGURE 1). Finally, the patient was diagnosed with disseminated sarcoidosis and hy‐ persplenism, which seemed to be the most like‐ ly cause of pancytopenia. A 46‐year‐old man was diagnosed with stage I sarcoidosis in 2010, but he did not agree to fur‐ ther follow‐up visits and investigations. He re‐ mained free of any disease symptoms until 2014 when progressive weakness and dyspnea occurred. Chest X‐ray and high‐resolution com‐ puted tomography scans showed bilateral hilar adenopathy and numerous subpleural reticular opacities—the manifestations consistent with stage II sarcoidosis. Surprisingly, the complete blood count (CBC) test revealed pancytopenia with a neutrophil count of 1.1 × 109/l, hemoglobin concentration of 10.5 g/dl, and platelet count of 3 × 109/l. The patient was transfused with plate‐ let concentrates and then referred to the Hema‐ tology Unit. On admission, his overall condition was good and an abdominal ultrasound showed hepatomegaly (anteroposterior [AP], 16 cm) and massive splenomegaly (AP, 20 cm). No other ab‐ normalities were detected. He remained pancy‐ topenic on the CBC test, but differential leuco‐ cyte counts were normal. Biochemical test re‐ sults were within normal ranges except for the serum β2 microglobulin concentration, which was markedly elevated to 8.27 mg/l (normal range, 1.5–3.0 mg/l). Protein levels, including immuno‐ globulin (Ig) G, IgA, and IgM concentrations, as well as electrophoresis were normal. Hemolysis and viral infections (human immunodeficiency