Abdominal pain and fullness in young patient

A 25-year-old man presented with abdominal pain and fullness within four months. On physical examination he was afebrile, with a blood pressure of 130/75 mm/Hg, a pulse of 74 beats per minute. The abdominal physical ex- amination revealed soft, distended abdomen with left up- per abdominal palpable mass. Blood tests showed the white-cell count was 11.400 per cubic millimeter (with normal eosinophils range), the hemoglobin level 16.2 g/dl (reference range : 13.6-17.2 g/dl), the platelet count 437000 per cubic millimeter, erythrocyte sedimen- tation 38 mm/h and C-reactive protein 45 mg/L (refer- ence range : 1.0-3.0 mg/L). Hepatic and renal function tests were all normal. Testing was negative for hepatitis B, hepatitis C and human immunodeficiency virus (on polymerase-chain-reaction assay). An ultrasonographic examination of the abdomen showed the vertical size of liver was 12 cm, mild increase in liver echo density with no gall stones. Ultrasonography also revealed a giant well defined, non-multilocular cystic lesion of the spleen with a size of 165 × 110 mm. Indirect hemagglutination test for hydatid cysts was positive in the titer 1:256.