Large retroperitoneal calcified hydatid cyst

Abstract

Large retroperitoneal calcified hydatid cysta ns_5152 950..951 A 62-year-old fat lady was admitted to the hospital complaining of vague, on and off abdominal pain for 3 years which became more severe from the last 3 months. On physical examination, no abnormalities were found.Ultrasonography of the abdomen revealed a huge cystic mass with thick rim in left retroperitoneal area.In intravenous pyelography, densely calcified lesion were seen on the left upper quadrant of the abdomen (Fig. 1, white arrow) pushing the left ureter medially (Fig. 1, black arrows). Computed Tomography (CT) scan of the abdomen demonstrates cystic lesion with thick peripheral wall calcification (Fig. 2). Liver and other abdominal organs did not have any lesions. Chest X-ray was normal too. There were no cysts in the liver and lungs. Avoiding the possible danger of ecchinococcal dissemination and/or anaphylactic reaction, we do not perform fine-needle aspiration biopsy of the mass. Although there are no specific signs or symptoms for the exact diagnosis of renal echinococcosis, without any abdominal abnormalities, pain attributes to the pressure effect of the mass.Serology for hydatid disease (immunofluorescent assay) was negative.The patient was scheduled for surgery with the impression of calcified renal hydatid cyst or infected simple cyst of the kidney or necrotic renal tumour.The round hard mass, attached to the lower pole of the left kidney, was removed surgically (Fig. 3) and contained a lot of germinal layers. The patient does well and was without abdominal pain 3 months after operation.Renal hydatid disease is rare (3% of case), usually solitary and located in the cortex. 1 Eighteen percent of renal hydatid cysts have Fig. 1. Intravenous pyelogram showing densely calcified lesion on the left upper quadrant of the abdomen (white arrow) pushing the left ureter medially (black arrows).Fig. 2. Computed Tomography scan showing hydatid cyst of left kidney with wall calcification.Fig. 3. View of the opened retroperitoneal cyst mass and germinal layers after removal of the lesion. Surgeons ANZ J Surg 79 (2009) 950-951been reported to rupture into the collecting system, leading to acutecolic and hydatiduria. The differential diagnosis of renal hydatidosis includes simple or infected renal cyst, abscess, and necrotic neoplasm. 2 Wall calcification and daughter cysts are often coexistent. Wall calcification may be a sign for dead cyst. Dead hydatid cyst may not have positive serologic test.The absence of a positive ecchinococcal serology does not rule out the disease. Nonspecific and insensitive tests, like the Cassoni intradermal test (which has 80% sensitivity and 70% specificity), the complement fixation test (which is positive in about 65% of patients), the indirect haemagglutination test (with 85% sensitivity), and the latex agglutination test, have been replaced by the enzyme-linked immunosorbent assay (ELISA), the indirect immunofluorescence antibody test, immunoelectrophoresis (IEP), and immunoblotting (IB) in routine laboratory appli...