Gastric fundus impression caused by a hepatic cyst mimicking gastric submucosal tumor.

To the Editor: Certain gastric submucosal tumors (SMTs) that are considered to be gastrointestinal stromal tumors (usually larger than 3 cm) require operative intervention because pathologic confirmation of its malignant potential is very difficult to make by endoscopic biopsy alone. As hepatic cysts may mimic the symptoms of a submucosal tumor, endoscopic biopsy is not sufficient for a diagnosis of an SMT, and endoscopic ultrasound should be performed for a definitive diagnosis.

We report a case in which a hepatic cyst mimicked a gastric SMT in a patient who had not undergone a preoperative endoscopic ultrasound (EUS). The differential diagnosis in this case, and other imaging methods that led to the correct diagnosis, are discussed.

A 54-year-old woman was admitted to the hospital for an operation on an incidentally detected gastric tumor. The gastric tumor was discovered on a routine health examination with endoscopy, and she was diagnosed as having a submucosal mass. The endoscopic evaluation demonstrated a protruding mass on the gastric fundus (Fig. 1A). The preoperative workup included a computed tomography (CT) scan that showed a cystic mass between the left lobe of the liver and the stomach (Fig. 1B). The scheduled operation was put on hold, and the radiologists were consulted regarding the exact location of the tumor. They reconstructed sagittal CT images (Fig. 1C) and made the diagnosis of a hepatic cyst externally compressing the gastric fundus.

The endoscopic differentiation of a true SMT from a submucosal lesion caused by extragastric structures might be difficult by endoscopy alone. This is especially true when a submucosal lesion is seen on the upper part of stomach, since in this region, the shape of the lesion usually does not change substantially when the patient's body position is changed. The causes of compression include the normal organs or structures (the splenic artery, spleen, liver, gallbladder, pancreas, colon and vertebra), and the extraluminal pathologic lesions (liver cyst, splenomegaly, splenic artery aneurysm, pancreatic pseudocyst, enlarged lymph nodes, and renal cyst). (1-5) The most common site of extrinsic compression is reported to be the upper part of the stomach. (2)

In most instances, such as in the present case, gastric SMTs are really just incidental findings that are diagnosed or suspected during routine upper gastrointestinal endoscopy. As an improperly diagnosed lesion may lead to unnecessary surgery, a correct diagnosis is especially important in these cases. Although CT studies are usually insufficient to differentiate true gastric SMTs from extrinsic compressions, we were able to make a correct diagnosis in our patient by using a reconstruction method of the sagittal image; thereby avoiding unwarranted surgery. This report emphasizes the potential diagnostic value of a routine preoperative EUS examination and CT scan for evaluation of the stomach wall.

[FIGURE 1 OMITTED]

In conclusion, a left hepatic cyst may, in rare instances, mimic an SMT arising from the gastric fundus on endoscopic examination, and appropriate diagnosis may require the use of EUS or reformatted CT images.

Sung-Soo Park, MD

Woo-Sang Ryu, MD

Jung-Myun Kwak, MD

Sun-Il Lee, MD

Wan-Bae Kim, MD

Young-Jae Mok, MD

Department of Surgery

Korea University College of Medicine

Seoul, Korea

Jae-Woong Choi, MD

Department of Radiology

Korea University College of Medicine

Seoul, Korea

Jong-Jae Park, MD

Young-Tae Bak, MD

Department of Internal Medicine

Korea University College of Medicine

Seoul, Korea

References

1. Rosch T, Kapfer B, Will U, et al. Accuracy of endoscopic ultrasonography in upper gastrointestinal submucosal lesions: a prospective multicenter study. Scand J Gastroenterol 2002;37:856-862.

2. Motoo Y, Okai T, Ohta H, et al. Endoscopic ultrasonography in the diagnosis of extraluminal compressions mimicking gastric submucosal tumors. Endoscopy 1994;26:239-242.

3. Hashimoto H, Mitsunaga A, Suzuki S, et al. Evaluation of endoscopic ultrasonography for gastric tumors and presentation of three-dimensional display of endoscopic ultrasonography. Surg Endosc 1989;3:173-181.

4. Norton ID, Jones DB. Endoscopic ultrasound: diagnostic and therapeutic applications. Intern Med J 2003;33:26-32.

5. Tio TL, Tytgat GN. Endoscopic ultrasonography of normal and pathologic upper gastrointestinal wall structure. Comparison of studies in vivo and in vitro with histology. Scand J Gastroenterol Suppl 1986:123:27-33.

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