Unusual Retrovesical Location Of Hydatid Cyst

Unusual Retrovesical Location Of Hydatid Cyst

A Forty-year old man presented with complaint of mild pain right hypochondrium and frequent micturition for last ten months. On clinical examination there was mild hepatomegaly, spleen was not palpable. Chest and cardiovascular examination was normal. Laboratory results showed haemoglobin level of 13.2gm% and a total leucocyte count of 8900/mm3 with 5% eosinophilia. Blood urea levels, creatinine levels, and the results of liver function tests were normal. Examination of urine and faeces revealed no pathological findings.
Ultrasound examination of the abdomen was carried out. Liver showed a well-defined, multiseptae cystic lesion in the right lobe of liver anteriorly showing multiple daughter cysts classic appearance of a hydatid cyst. There was no evidence of calcification. Ultrasonography also revealed another well defined heteroechoic cystic lesion with evidence of internal septations in the pelvis posterior to the bladder displacing the bladder forwards. There was no evidence of calcification. No other cyst was noted. Chest X-Ray was normal. Indirect Hemagglutination test for E.granulosis was positive. A diagnosis of coexistent hepatic and pelvic hydatid was made.

Hydatid disease (Echinococcus granulosus) is endemic in India as well as other parts of the world, including Middle East, Africa, New Zealand, Australia, Turkey and Southern Europe. The clinical presentation of the hydatid disease depends on the size and the site of the lesion and accessibility of the organ involved for clinical examination. Eosinophilia can be present as expected for parasitic infestations. As in this case, the diagnosis of hydatid can be made with US and confirmed by a CT scan. The MRI is also helpful in cardiac and intracranial hydatidosis. Different serological tests can be carried out for the diagnosis, including enzyme-linked immunosorbent assay (ELISA) and indirect haemagglutination (IHA) test. [1]

Localisation of cysts is mostly hepatic or pulmonary but peritoneal, splenic, pancreatic, thyroid, muscular and bone lesions are also reported. Juxta vesical location, preponderantly retrovesical, is rare. The position follows a tear of a cyst in the superior abdominal area, usually hepatic or splenic, and the parasite settles in the pelvic region of the peritoneal cavity, where a new cyst forms. Such a rupture can occur spontaneously or result from trauma at the operation. Very often the pelvic cyst coexists with a hepatic one, detected before or on the same occasion, so that these cysts are secondary in most cases. [2]

Pelvic localization may be considered primary if no other site is found to be affected. Such cysts are mostly retrovesical and are even more rare. [3]

Most frequent presenting symptoms in retrovesical hydatid cyst are frequency, urgency, burning micturition and urinary retention. Although clinical symptoms and signs are not specific of retrovesical hydatid cyst, hydatiduria, which is characterized by the presence in urine of gelatinous material and membranes reminiscent of grape skins in texture, is pathognomonic of a hydatid cyst ruptured in the urinary tract. [4]

Ultrasonography is the key diagnostic tool in the cases of hydatid cyst. Sonographic appearance can be either a simple cyst containing no internal architecture except sand, cysts with detached endocyst secondary to rupture, cysts with daughter cysts and matrix and densely calcified masses. CT is useful when the diagnosis is in doubt or to determine the relation with other adjacent organs. [4]

Retrovesical hydatid cyst is uncommon even in endemic areas. It results from peritoneal seedling of a intraperitoneal cyst or from haematogenous dissemination. The present case highlights the role of Ultrasound in diagnosis of retrovesical hydatid cyst, a rare location for hydatid cyst.

REFERENCES
Abu-Eshy SA. Some rare presentations of hydatid cyst (Echinococcus granulosus). J R Coll Surg Edinb. 1998; 43(5): 347-52.
Neagu V, Ioanid PC. Juxtavesical hydatid cysts. Eur Urol. 1978; 4(2): 111-4.
Basaranoglu M, Sonsuz A, Perek A, Perek S, Akin P. Primary pelvic hydatid cyst. J Clin Gastroenterol. 1998; 26(2): 157-8.
Horchani A, Nouira Y, Chtourou M, Kacem M, Ben Safta Z. Retrovesical hydatid disease: a clinical study of 27 cases. Eur Urol. 200; 40(6): 655-60.