427virus, hepatitis B virus, hepatitis C virus, cytomegalovirus, and Epstein-Barr virus) were excluded. Blood and urine cultures were negative. Tuberculosis was excluded. Serum iron and folic acid levels were normal, while a moderate vitamin B 12 deficiency was detected (101 pg/ml; normal range, 157-1057 pg/ml). A small proportion of erythroblasts had dysplastic features on bone marrow (BM) aspiration, which might be consistent with vitamin B 12 deficiency; however, an early phase of myelodysplastic syndrome was also considered. Thus, a trephine biopsy was performed. Considering the results of the BM biopsy, the patient received vitamin B 12 injections at a dose of 0.1 mg daily intramuscularly, then once a week for a total of 2 months, but pancytopenia persisted. The biopsy did not reveal any potential causes of pancytopenia, and no dysplastic features were demonstrated. Nevertheless, an oval sarcoidal granuloma consisting of epithelioid histiocytes and multinucleate giant cells was observed in the hematoxylin and eosin stain of the biopsy. The granuloma was sparsely surrounded by a rim of lymphocytes. Necrosis was not observed (FIGURE 1). Finally, the patient was diagnosed with disseminated sarcoidosis and hypersplenism, which seemed to be the most likely cause of pancytopenia.A 46-year-old man was diagnosed with stage I sarcoidosis in 2010, but he did not agree to further follow-up visits and investigations. He remained free of any disease symptoms until 2014 when progressive weakness and dyspnea occurred. Chest X-ray and high-resolution computed 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 × 10 9 /l, hemoglobin concentration of 10.5 g/dl, and platelet count of 3 × 10 9 /l. The patient was transfused with platelet concentrates and then referred to the Hematology 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 abnormalities were detected. He remained pancytopenic on the CBC test, but differential leucocyte counts were normal. Biochemical test results were within normal ranges except for the serum β 2 microglobulin concentration, which was markedly elevated to 8.27 mg/l (normal range, 1.5-3.0 mg/l). Protein levels, including immunoglobulin (Ig) G, IgA, and IgM concentrations, as well as electrophoresis were normal. Hemolysis and viral infections (human immunodeficiency