1004 | Case Report Primary Hydatid Cyst of the Kidney in a 10 Year Old Boy Ali Tehranchi,1 Hamid Mohammadi Bukani, 1 Ali Modabberi Delshad, 1 Sepehr Hamedanchi1 Keywords: Case Reports; kidney Diseases; Hydatid Cyst; Echinococcosis; Humans INTRODUCTION Kidney involvement in echinococcosis is extremely rare, accounting for only 2-3% of all cases. Primary involvement of the kidney with sparing the liver and lungs is even more rare.(1) We report a rare case of primary renal hydatid disease presenting with suprapubic and left loin pain. In this case, the disease mimicked renal tumor. Successful treatment was accomplished using radical nephrectomy. CASE REPORT A 10 year old boy, living in a rural environment, presented to our hospital with chief com- plaint of dull pain in left loin and lower abdomen for the last month. The patient had no his- tory of urinary tract infection, hematuria or hydatiduria. His medical history was unremark- able, however he had a history of being in contact with livestock and sheepdogs. On physical examination, there was only mild tenderness in suprapubic and left loin areas, and no mass was palpable in the abdomen. His body temperature and the rest of systemic examination were normal. Urine analysis and serum blood chemistry were normal. The chest x-ray was normal (Fig 1). The ultrasound revealed a multiseptate cystic mass measuring 50 × 52 mm in diameter in the lower pole of the left kidney (Fig 2). Other abdominal organs were normal. Computed tomography (CT) scanning confirmed ultrasonographic findings and the mass was consistent with Bosniak class IV cysts (Fig 3). Correspondence Address: Hamid Mohammadi bukani, MD Urology and Nephrology Re- search Center, Department of Urology, Imam Medical Center, Urmia University of Medical Sciences, Urmia, Iran Tel: +984413459538 Fax: +984413469935 E-mail: Hamid_Boukani@ yahoo.com Received May 2011 Accepted August 2011 1Urology and Nephrology Re- search Center, Department of Urology, Imam Medical Center, Urmia University of Medical Sciences, Urmia, Iran CASE REPORT 1005Vol. 10 | No. 3 | Summer 2013 |U R O LO G Y J O U R N A L A provisional diagnosis of a malignant cystic mass was made and anterior subcostal transperitoneal approach for radical nephrectomy was elected. The patient didn’t re- ceived preoperative Albendazole. The mass had extensive adhesions to the left colonic mesentery, which might be a characteristic sign for hydatid disease. The kidney was re- moved intact without rupture. Gross pathologic examina- tion showed a cystic structure in the lower pole of the kid- ney with parenchymal destruction, which was surrounded by a thin rim of renal cortex (Fig 4). The histopathological examination revealed a hydatid cyst with three layers. Adjacent renal tissue showed severe infil- tration of eosinophils and lymphocytes. Because of complete specimen removal without spillage, after the surgery the patient was not given Albendazole, and he was referred to infectious disease clinic. DISCUSSION According to the age of the patient and findings of abdomi- nal CT scan, preoperative differential diagnoses were mul- tilocular cyst, cystic renal cell carcinoma, cystic Wilms’ tumor and hydatid cyst. Hydatidosis, caused by Echinococcus spp. (E. granulosus and E. multilocularis in Iran) is one of the most important zoonotic diseases. Ingesting embryonated eggs through ma- terial contaminated infects humans; the larvae reach sys- temic circulation and transport to the liver, lungs and other organs. The asymptomatic period is too long and the disease might be diagnosed even after 20-25 years post infection.(2) The most common symptoms are palpable mass, flank pain, hematuria, malaise, and fever. Hydaturia is a pathognomon- ic sign. Its origin is a grape-like material in the urine result- ing from the rupture of the cysts into the collecting system. Hydatid Cyst of the Kidney | Tehranci et al Figure 1. Chest x-ray. Figure 2. The ultrasound showing a multiseptate cystic mass. Figure 3. CT scan showing a Bosniak class IV cystic mass in the left kidney. 1006 | It has been reported in 5% to 25% of all renal hydatidosis cases. In a study of 11 patients with renal Hydatidosis 7 (63.6%) had flank pain, 1 (9.1%) had post ejaculation pain, and 3 (27.3%) were asymptomatic.(3) Primary hydatidosis of the kidney is very rare, even in en- demic areas such as Iran. Diagnosis of the hydatid cyst is made on the basis of serologic tests and/or imaging studies. The possibility of a striking clinical resemblance between a hydatid cyst and malignant disease of the kidney has been emphasized in the English literature. We also indicated this important point in our patient. In conclusion, the most important factor in the diagnosis of hydatid disease is the high index of suspicion about its pos- sibility. Primary hydatidosis of the kidney should always be considered in the differential diagnosis of any cystic renal mass in the pediatric groups, even in the absence of accom- panying involvement of liver or other visceral organs.(4) CONFLICT OF INTEREST None declared. REFERENCES 1. Mongha R, Narayan S, Kundu AK. Primary hydatid cyst of the kidney and ureter hydatiduria; a case report. Indian J Urol. 2008;24:116-7. 2. Rokni MB. Echinococcosis / Hydatidosis in Iran. Iranian J Parasitol. 2009;4:1-16. Case Report Figure 4. Gross pathologic examination of the left renal mass. 3. Zargar-Shoshtari M, Shadpour P, Robat-Moradi N, Moslemi M. Hydatid cyst of urinary tract: 11 cases at a single center. Urol J. 2007;4:41-5. 4. Hallaji F, Varedi P, Mahmoodi S, Noroozi SG, Mostafavi H, Mostafavi SR, Jouibari KM. Hydatid disease: a cause of renal cystic masses in children. Pediatr Nephrol. 2009 Jun;24:1251-2.