Abstract
Hydatid disease is generally infested by echinococcus and commonly affects liver or brain. The hydatid disease in retroperitoneum area is a rarity. We present one such case.

Introduction

Hydatid disease which is an infestation by the larvae of echinococcus granulosus, is not common in this part of India and usually liver is involved. Hydatid disease occurring in retroperitoneum is rare. One such case which presented as lump in the right iliac fossa is presented here. The USG and CT scan were inconclusive and finally the diagnosis could only be achieved on exploration of the mass.

Case Report

A 50 year old man presented in M.B. Hospital, Udaipur on 27/2/06 with complaints of gradually increasing painless swelling in the right side of abdomen from past 20 years. He also complained of constipation from 5 months and mild, dull aching, non-radiating pain in the right iliac fossa from past 3 months, aggravated by working and relieved at rest and had increased in severity from 15 days. Patient also had acute retention urine from 3 days with burning micturition, poor stream, hesitancy, increased frequency, dribbliing and soiling of his clothes.

On inspection, the patient had fullness in lower abdomen more in the right iliac fossa, extending in the right lumbar region and umbilical and hypogastric region, irregular in shape, 6" x 3" in size with ill defined margins, with normal overlying skin.

On palpation, there was a non-tender, intra-abdominal irregular shaped lump in the right iliac fossa extending in the umbilical, right lumbar and hypogastric regions 6" x 3" in size, soft cystic in consistency, which was non-reducible, non-compressible, with no fluid thrill or impulse on coughing.

On per rectal examination, the anal tone was normal, rectum was empty collapsed with normal mucosa and moderately enlarged, firm prostate. The swelling was not palpable on per rectal examination.

The patient was evaluated with the barium enema showing extraneous mass compressing the caecum in that lower part and caecum and ascending colon were pushed medially (Fig. 1). Ultrasonography showed cystic mass in the right iliac fossa with bilateral hydronephrosis, more on the right side, with enlarged prostate. CT scan showed right psoas muscle tear with acquired haematoma? Lymphangioma and bilateral hydronephrosis and enlarged prostate and normal liver. On aspirating, thick creamy fluid similar to pus was aspirated. Cystoscopy showed BHP grade I. Patient had haemoglobin - 8.7; B.T. -1’22"; C.T. - 3’55"; normal urinalysis, blood sugar - 95 mg/dl; serum urea - 40.4 mg/dl; serum creatinine - 1.5 mg/dl; normal X-ray chest and X-ray abdomen; normal ECG, PSA - 10.85 ng/dl.

Retroperitoneum was explored by right iliac fossa incision and about 500 ml of thick, creamy fluid came out. Daughter cysts were removed and the cavity was lavaged with 10% povidove iodine solution and malecot’s drain was put. The creamy fluid was due to degeneration of germinal layer.

Postoperatively, drain was kept for 5 days with minimal serous discharge and patient was discharged after removing the drain.

In the immediate postoperative period, patient was given Ampicillin Cloxacillin combination alongwith gentamycin and metronidazole. Patient was discharged with albendazole.

Fig. 1 : Barium enema showing caecum and ascending colon pushed medially by mass. Fig. 2 : CT scan abdomen showing mass in right side of abdomen and torn psoas abdominis muscle.

Fig. 3 : On approach through iliac incision into retroperitoneum, pale creamy fluid came out on opening the mass. Fig. 4 : Multiple hydatid cyst seen floating in creamy thick fluid. Fig. 5 : Postoperative photograph showing incision site and malecot's catheter draining the cavity.

Discussion

The case presented here was isolated hydatid cyst appearing in retroperitoneum in the region of right iliac fossa. Though studies have shown that intra and retroperitoneal hydatid disease is mostly the result of spontaneous, traumatic or surgical rupture of a hydatid cyst, Engin et al, Gurdal et al mentioned that primary retroperitoneal hydatidosis is extremely rare and only occasional cases have appeared in literature.^1,2 Zhinapour and Basiratnia reported a case in which a 38 years old man had hydatid disease of lower lumbar vertebrae, sacrum, lumbosacral spinal canal and left iliac bone; with extension to retroperitoneum and piriforms, sacrospinalis, iliacus, iliopsoas quadratus lumborum muscles; without involvement of liver or lung.³

Chowbey et al presented a case of hydatid cyst which was removed endoscopically.⁴

Gurdal et al presented a case of primary retroperitoneal hydatid cyst which was given a preoperative diagnosis of adrenal mass and was treated by adrenalectomy and partial nephrectomy.⁵

Zerem et al presented a controlled trial of 84 patients in whom percutaneous drainage combined with albendazole therapy was found to be effective and safe for the treatment of abdominal and retroperitoneal hydatid cysts.⁶ Albendazole (10 mg per kilogram of body weight per day) was given for eight weeks. After an initial rise, the echinococcal-antibody titre fell progressively and at the last follow up (24 months) were negative.

Hatipoglu et al reported two cases of hydatid cyst presenting in retroperitoneum.⁷ One of the cyst was in the minor pelvis and other was in the left psoas muscle. In the present case report, the hydatid cyst was also in relation to the right psoas muscle which on CT scan showed torn right psoas muscle.

References

1. Engin G, Acunas B, R Ozanes I, et al. Hydatid disease with unusual localization. Eur Radiol 2000; 10 : 1904-12.
2. Gurdal M, Kirecci S, Yucebas E, et al. Primary retroperitoneal hydatid cyst with unusual clinical manifestations. Urol Int 2004; 73 : 92-4.
3. Zhianpous M, Basiratnia R. Widespread hydatidosis of sacroiliac bones and retroperitoneum. Iran J Radiol 2004; 25-27.
4. Chowbey PK, Wadhwa A, Shah S, Sharma A, Khullar R, Soni V, Bijal M. Endoscopic management of a retroperitoneal hydatid cyst, Journal of laparoscopic and Advanced Surgical Techniques. Part A 2004; 14 (4) : 236-40.
5. Gurdal M, Kirecci S, Yucebas E, Karaman MI. Primary retroperitoneal hydatid cyst with unusual clinical manifestation. (Review) Urologic Internationalis 2004; 73 (1) : 92-4.
6. Zerem E, Sabanovic Z, Smajic M. Percutaneous treatment of abdominal and retroperitoneal echinococcal cysts using ultrasonography. Medicinski Arhiv 2003; 57 (1 Suppl 2) : 71-3.
7. Hatipoglu AR, Corkun I, Karakaya K. Retroperitoneal localization of hydatid cyst disease. Hepato-Gastoenterology 2001; 48 (40) : 1037-9.

*Associate Professor; **Senior Registrar, Department of Surgery, RNT Medical College and MB Hospital, Udaipur 313 001.