CASE REPORTS A Grossly Distended Gallbladder Masquerading as an Infected Hydatid Cyst of the Liver A n 87 year old woman was referred with symptoms of loss of weight, loss of appetite and nausea. Physical examination revealed a large, non-tender mass in the right side of the abdomen thought to rep- resent a possible cystic kidney. Previous chest radiographs had demonstrated a large calcified hydatid cyst in the right lobe of the liver, as also shown by computed tomography (CT) (Figure 1). Previous barium enema had also demonstrated the large calcified echinococcus cyst and the colon had been markedly displaced to the left due to an infrahepatic mass. Further CT sections dem- onstrated an apparently septated, low attenuation mass 10 cm below the calcified hydatid cyst, in the inferior as- pect of the liver. The mass re- vealed a fairly thick enhancing wall, did not contain any cal- cification, but demonstrated a WFC van Gelderen Department of Radiology, Wanganui Base Hospital, Wanganui, Newlealand Figure 1: CT demonstrates Il heavily ca/c/fled hydatid cyst superiorly in the right lobe of the liver. 29 SA JOURNAL OF RADIOLOGY. May 1996 small pocket of air in its anterior as- pect (Figure 2). The remainder of the liver was normal, but the gallbladder could not be identified. Subsequent ultrasound (US) examina- tion (Figure 3) confirmed the calcified hydatid cyst. It also demonstrated the hypoechoic mass related to the inferior as- pect of the liver, containing multiple small hyperechoic areas, thought to confirm pockets of air as they were almost offluo- rescent" echogenicity and the acoustic shadows cast were not remarkable. As the gallbladder was not separately identified, a huge distended infected gallbladder was considered in the dif- ferential diagnosis, but in view of the other definite echinococcus cyst, a sec- ond infected hydatid cyst was advanced as a more likely diagnosis. Militating against either diagnosis was the absence of significant pain or tenderness. Figure 2: CT section 10 em below image in Figure 1, reveals a large septated mass of low attenuation situated at the inferior aspect of tile liver containing a pocket of air anteriorly. This was thought to represent an Infected hydatid cyst. The gal/bladder was not visualised. A cholecystotomy was performed re- vealing a grossly distended thick walled gallbladder containing an enormous number and variety of gallstones. Finger palpation of the interior of the gallbladder revealed a probable gallbladder carci- noma and histology after punch biopsy confirmed this diagnosis. to page 3D OFFICE: EUROPEAN CONGRESS Or RAOIOLOGY - ECR'97 NEUTORGASSE 9/2A A-lOlO VIENNA 1AUSTRIA PilONE: (+431 I) 533 40 64, 533 40 65, 533 40 66 FAX: (+43/1) 533 40 649 EMAIL: orFICE@ECR.TELBCOM.AT WWW: WWW.rCR.TELECOM.AT\ECR A Grossly Distended Gallbladder Masquerad ing as an Infected Hydatid Cyst of the Liver DEADLINES: Figure 3: A transverse US section of the mass demonstrates a thick walled structure containing multiple small bright hyperechoiC areas casting unremarkable shadows. This was erroneously thought to confirm the CT findings of an infected hydatid cyst. The surgeon's comment was as follows: "None of the many thousands of stones of all varieties and sizes were reported on US or cr scanning, nor was the carcinoma of the gallbladder". The CT and US images have subse- quently been shown to radiological col- leagues at other hospitals, and there was some reassurance in that they did not make a correct diagnosis more readily. The above case report demonstrates just how difficult it can be to establish a correct diagnosis, even ifthe disease proc- ess is of enormous proportions. In retro- spect the non-visualisation of the gallbladder on both CT and US should have alerted one, but even then this is a well-known occurrence ifthe patient had had a meal before the examination. SUBMISSION OF ABSTRACTS: SEPT. 20, 1996 REDUCED REGISTRATION FEE: DEC. 2, 1996 ADVANCE REGISTRATION: JAN. 31,1997 30 SAJOURNAL OF RADIOLOGY· May 1996