We report the case of a young lady who presented with a symptomatic cystic lesion arising from the right upper quadrant of the abdomen. Ultrasonography and computed tomography suggested a diagnosis of a hydatid cyst of the right lobe of liver. She had a positive serology for Echinococcus granulosus and showed cyst regression on antihelminthic therapy. At laparotomy a right suprarenal cystic lesion was found and excised. Histopathological examination revealed it to be a pseudocyst arising from the suprarenal gland.

Introduction
Suprarenal cysts are uncommon. Most are asymptomatic and are discovered on abdominal imaging for some other cause or at autopsy.1 Pseudocysts are the most common adrenal cystic lesions.1,2 We report the case of a young woman who was diagnosed as a hydatid cyst of the liver on ultrasonography and computed tomography. On exploration the liver was normal, instead a cystic lesion was found arising from the right suprarenal that turned out to be an adrenal pseudocyst on histopathology.

Case Report
A 20 year old married lady with 2 children presented with history of dull ache in the right upper abdomen since 1 year, associated with a palpable progressively enlarging lump. There was no associated jaundice, fever, urinary or gastrointestinal complaints . On examination the only positive finding was a non tender cystic lump which seemed to arise from the right lobe of the liver Initial evaluation by ultrasound showed a cystic lesion with internal echoes in the right lobe of the liver measuring 14 cms into 8 cms (Fig. 1). Her liver function tests, haemogram and urine examination were normal. ELISA for Echinococcus granulosus was positive. A CT scan was done which showed a hypo dense lesion with internal debris arising from segment 6 of liver, measuring 12 x 8 x 5 cms and abutting the upper pole of right kidney (Fig. 2). She was diagnosed as a case of hydatid cyst of the right lobe of liver and given albendazole 10 mg/kg/day orally for 3 months. On repeat evaluation after 3 mths, the cyst had regressed both clinically and on ultrasound. The ultrasound showed the cyst to measure 5 cms in diameter and the contents had become more echogenic (Fig. 3). The patient however complained of persistent pain and was taken up for surgery with the diagnosis of a right lobe liver hydatid.

The abdomen was approached by a right subcostal incision. The liver and general abdominal cavity was normal. A 5 cm diameter cystic lesion with organized content was found to arise from the upper pole of right kidney with normal suprarenal gland forming part of its wall. The lesion was abutting the adjacent liver without any infiltration. The cystic lesion was excised and sent for histopathology.

Histopathological examination showed it to be a pseudocyst with normal adrenal gland forming part of its wall. The cyst was devoid of any lining epithelium but multiple haemosiderin laden macrophages were present in the wall. The cyst was full of organized clot. No dilated vascular channels were seen in the pseudocyst wall.

The postoperative course was uneventful and the patient was discharged on the 3rd postoperative day.

Fig.1 : Ultrasound of the patient at presentation showing a cystic lesion arising from the right lobe of the liver.	Fig. 2 : CT scan at presentation showing large cystic lesion in the segment 6 of the liver.
Fig. 3 : Ultrasound image after 3 months of anti-helminthic therapy showing regression in size and increased echogenecity of the cyst contents.

Discussion
Cysts of the adrenal gland are rare with reported incidence of 0.073 %.2 Four pathological types have been described: parasitic, epithelial, endothelial and pseudocysts.1 Of these pseudocysts are the commonest comprising 36-56%.1,2 Two theories have been proposed to explain the origin of these pseudocysts. They arise due to adrenal haemorrhage secondary to trauma, burns, sepsis, pregnancy, etc or due to rupture of dilated vascular channels from a vascular malformation in the adrenal gland.2,3 A number of authors have reported on the presence of dilated vascular channels in the pseudocyst wall.3 This seems to justify the vascular origin of these pseudocysts. However, in many cases, such as our case, no dilated channels were found and the aetiology is unknown. In addition, in our patient no cause of adrenal haemorrhage could be identified in the history.

Suprarenal pseudocysts are 2-3 times more common in females than males.1,2 They occur with equal frequency on either side. Most are asymptomatic and are incidentally detected. Some cases may present as a symptomatic lump (the present case). Few cases of hypertension have been reported with pseudocysts associated with raised catecholamine levels, which were misdiagnosed as phaeochromocytomas.4 A few patients have presented with shock and infection.5,6

Diagnosis is sometimes made on ultrasonography and CT scan.1,2 However, correct preoperative diagnosis is possible in less than two third of cases because of variable features on imaging.2 Some pseudocysts are purely cystic while others may be partially cystic or mixed cystic and solid.7 Cysts with solid component are often difficult to distinguish from cystic adrenal tumours. The presence of layering and absence of contrast enhancement of solid areas suggests the diagnosis of pseudocysts.7 Right sided lesions can be difficult to differentiate from the more common cystic lesions arising from the adjacent segment 6 of the liver on imaging especially in the absence of any identifiable cause of adrenal haemorrhage such as trauma, burns, sepsis, etc.

Treatment is required for symptomatic cysts and in case where diagnosis is not certain.1,2 Conventional and minimally invasive approaches have both been described with equal success.2,8,9 The diagnosis is usually a pathological surprise.

Conclusion

Suprarenal pseudocysts are uncommon. They probably occur secondary to adrenal haemorrhage and are more common in females. Large right-sided lesions may be mistaken for a hepatic cyst in segment 6, despite ultrasound and CT scan imaging. In most cases of adrenal pseudocysts, no identifiable cause of adrenal haemorrhage can be determined. Treatment is required for symptoms and in case of uncertain diagnosis. Minimally invasive and open techniques are equally effective. Diagnosis is usually made after excision on histopathological examination.

References

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