Gastrointestinal stromal tumor mimicking peritoneal hydatid cyst

ABSTRACT

A 63-year-old woman, with a significant past medical history for hypertension, was admitted to surgical department B of Charles Nicolle Hospital suffering since twenty years from diffuse abdominal pain and progressive increase in abdominal volume. No general state deterioration was reported. Abdominal exam showed two palpable masses. The first one localized in the upper right quadrant and measuring 15cm. The second mass, palpable in the left paraumbilical quadrant, measured 20cm. No jaundice was found. Computed tomography evidenced two septated cystic lesions in segment IV and VIII of the liver with peripheral calcification [Fig 1], a multi-cystic formation in the left sub hepatic area and a huge splenic cyst with multiple- septa [Fig 2]. Regarding high prevalence of hydatid disease in Tunisia, all cysts were considered as hydatid cyst. Patient received preoperatively albendazole [10mg/kg/day] during two weeks and was operated on through a median laparotomy. Intraoperative exploration found in the liver four contiguous cysts sitting on segment IV. After sterilization with hypertonic solution, multiple daughter cysts were evacuated. No communication between biliary ducts and cyst cavities was mentioned. Liver cysts were treated by unroofing procedure combined with omentoplasty. In the spleen, there was a cyst of 20cm of diameter suspended to its lower part. A partial resection of splenic cyst was performed after sterilization of cyst cavity and evacuation of daughter cysts. The cyst of the left sub hepatic area measured 10cm of diameter and had a partial contact with the posterior wall of the stomach. After the sterilization of the cyst, its content was aspirated but no hydatid liquid or daughter cyst was recuperated. A cystectomy was performed with a remnant cavity of only 2cm against the posterior wall of the first part of duodenum. The patient had an uneventful postoperative course and was discharged six days later. Pathology of this peritoneal cyst concluded to stromal tumor. The resection of this tumor was incomplete, since then patient was treated with imatinib-mesylate, 400 mg once daily. Computed tomography performed six months post operatively showed no residual tumor [Fig 3]