Differential diagnosis of gastric submucosal masses and external pressure lesions

Abstract

Lesions of the left triangular ligament of the liver are rare, and there are even fewer cases of vascular tumors misdiagnosed as gastrointestinal stromal tumors. We comment on the two cases reported in the article. The article did not include pictures of laparoscopic surgery, making it unconvincing. For gastric submucosal lesions, enhanced computed tomography venous phase imaging may be beneficial for differential diagnosis. Although endoscopic ultrasound is an effective tool for diagnosing submucosal lesions of the stomach, due to various factors, it cannot achieve an accurate diagnosis. During endoscopic examination, a more accurate diagnosis can be made depending on the personal experience of the operators.

Key Words: Differential diagnosis; Gastric submucosal masses; External pressure lesions; Endoscopic ultrasonography; Computed tomography

Core Tip: We have raised some issues regarding the two cases reported in the article. No figures of laparoscopic surgery are shown in the article, which lacks persuasiveness. For gastric submucosal lesions, the accuracy of enhanced computed tomography venous phase imaging combined with endoscopic ultrasound diagnosis is high. During endoscopic examination, a more accurate diagnosis can be made based on the characteristics of gastric submucosal lesions.

TO THE EDITOR

We have read the article reporting two cases of left triangular ligament hemangioma of the liver misdiagnosed as gastrointestinal stromal tumors[1], which are very rare and attract attention. It is difficult to make a definitive diagnosis before surgery based on imaging findings, and the rate of misdiagnosis is extremely high. The misdiagnosis results in the selection of wrong treatment plan. Both patients were mistakenly treated with endoscopic therapy. Fortunately, the error was discovered during the operation and converted to laparoscopic surgery, which ultimately achieved good clinical outcome and avoided medical disputes. However, there are still some issues that need to be addressed.

The author did not include figures of the laparoscopic surgery. The left triangular ligament is a double-layered peritoneum that runs on the upper surface of the left lobe of the liver and varies in length. Medially, the anterior layer merges with the left layer of the falciform ligament, while the posterior layer merges with the left layer of the lesser omentum. The left triangular ligament is located in the front of the abdominal esophagus, the upper end of the lesser omentum, and the stomach fundus. Therefore, for lesions near the left triangular ligament of the liver, it is normal to have lesions near or compressing the gastric fundus. Conventionally, the tumor in the left triangular ligament of the liver should be located on the diaphragmatic surface of the liver or above, outside, and in front of the stomach fundus. However, in these two cases, both lesions were located on the visceral surface of the left lobe of the liver and on the inner side of the gastric fundus, which is very rare.

The left triangular ligament of the liver without lesions is difficult to display on computed tomography (CT). In the two presented cases, due to the limited and discontinuous CT images, it is impossible to determine the relationship between the lesions and the left triangular ligament of the liver. To determine the relationship between the lesion and the gastric wall may be helpful to observe the continuity of the enhanced gastric mucosa during the venous phase. The author did not show the gastric mucosa after venous phase enhancement in the images presented, making it even more difficult to determine the origin of the tumor. From the only four CT images included, it is highly likely that the tumor is misdiagnosed as originating from the stomach, especially in the second case, which was a tumor that grows entirely within the gastric cavity, while the first case may be misdiagnosed as an intramural tumor.

Ultrasonic endoscopy (EUS) can determine the location of lesions with the aid of an endoscopic optical system. Using a high-frequency probe, it can explore the structure of each layer of the stomach wall, clearly visualize adjacent tissues or organs, and diagnose lesions based on the origin level of the tumor, the uniformity and intensity of the echo. Due to the direct contact of the ultrasound probe with the digestive tract lumen, there is no abdominal wall attenuation, and it is almost unaffected by gas when close to the lesion, allowing for clearer images to be obtained, especially in the display of superficial or small lesions, which is significantly better than conventional ultrasound. Therefore, EUS can accurately differentiate between extramural pressure lesions and submucosal lesions in the stomach wall[2], and even achieve an accuracy rate of 100%[3]. The accuracy of EUS diagnosis is also affected by many factors such as lesion size, location, obesity, etc. Combining CT can further improve the accuracy of diagnosis of gastric submucosal tumors[4]. Therefore, for lesions in specific areas, the layers of the stomach wall may not be clearly displayed, resulting in misdiagnosis. In particular, for larger tumors, one cannot rely solely on EUS to make a final diagnosis.

In addition, the characteristic of external pressure tumors is that they are generally large, and sometimes change depending on the patient's position or breathing. The color of the mucosa at the lesion site is usually the same as the adjacent normal mucosa, and there may be mucosal folds. A gastric submucosal tumor has relatively smooth mucosa, sometimes with mucosal congestion or telangiectasia. Biopsy forceps can also be used for probing. External pressure can generally move the mass, while gastric submucosal masses generally have little or no mobility.

In summary, the two cases reported in this article are indeed very rare, and have a high reference value and warning effect for the diagnosis of gastric submucosal tumors. Based on our personal experience, we have made some comments regarding the lack of laparoscopic surgery figures, the anatomy and imaging of the left triangular ligament of the liver, the technical specificity of endoscopic ultrasonography, and the differential diagnosis of gastric submucosal tumors during endoscopic examination. We appreciate your feedback and suggestions.