Gastric submucosal lesion caused by an embedded fish bone: A case report

INTRODUCTION

Mistaken ingestion of a foreign body (FB) is common in children and adults. Being at the exploratory stage of development, children tend to put objects in their mouths[1,2]. In adults, ingestion of a FB usually occurs in those who are diagnosed with psychiatric disorders and pica[3], and prisoners who try to escape from law enforcement during access to medical service[4]. An ingested FB can become lodged in any part of the gastrointestinal tract. Depending on the FB and lodged position, FB ingestion can cause serious complications such as obstruction, perforation and bleeding. Therefore, ingestion of a FB should be paid due attention in clinical practice.

The ingestion of a fish bone has been shown to be a common cause of a FB in the digestive tract in the emergency department[5]. In clinical settings, most FBs in the digestive tract can be successfully removed with the assistance of endoscopy.However, a few FBs may lodge in the digestive tract for a long time, which can lead to other diseases or complications. Submucosal lesions are caused by tumors that stem from the muscularis mucosa, submucosa, or muscularis propria. Submucosal lesions are frequently found in the gastrointestinal tract, especially in the stomach, as often as 1 in every 300 endoscopic examinations[6]. Here, we report a patient with a fish bone embedded in the gastric antrum who presented with the manifestations of a submucosal tumor (SMT).

CASE PRESENTATION

Chief complaints

當前，地下室人防工程已越來越重要，其主要原因有以下兩個方面：一是戰備方面，當前的國際形勢復雜多變，我國面臨著多重安全威脅，一旦發生戰爭，特別是現代化戰爭，如果沒有人民防空工程，廣大人民群眾的生命財產安全將得不到保障；二是社會經濟方面，隨著經濟的快速發展，城市土地資源越來越少。因此，合理開發和綜合利用地下空間，為保護生態環境、節約土地資源、緩解城市人口密集、地面交通擁擠等矛盾，實現城市建設的科學發展提供了新途徑。

History of present illness

There were no obvious reasons for her abdominal pain and discomfort after meals.Her discomfort was usually relieved after 30 min rest. A fatty diet did not aggravate the development of her discomfort or radiate to her shoulders or back. No acid reflux,belching, hiccups or black stools were reported.

History of past illness

The patient had no previous noteworthy medical history.

Family history was pertinent for her mother who was diagnosed with gastrointestinal stromal tumors aged 70 years.

Personal and family history

《路史》云：“女媧始治于中皇山，繼興于驪山之下，中皇山即女媧山，有天臺鼎峙，今建女媧廟?！碧扑我詠?，女媧廟歷經修葺擴建，尤其是清乾隆元年重修后，擁有正殿四重，房屋百余間，是當時平利最大的寺院，被譽為“名勝之方”。

Physical examination

The abdomen was soft and flat, with no spontaneous pain or tenderness. No positive results were found on physical examination.

Submucosal tumors (SMTs) are elevated lesions which originate from the layers below the mucosa of the digestive tract, including the muscularis, submucosa, and muscularis propria[7]. The mechanism of SMTs involves abnormal hyperplasia in submucosal tissue or the muscle layer and genetic factors also play a critical role in this process. Patients with SMTs are often asymptomatic, and most SMTs are found during routine health screening. In recent years, due to the wide application of endoscopy and EUS in clinical practice, the detection rate of SMTs has increased. Although the exact incidence is unknown, the detection rate of SMTs by gastroscopy is 0.33%-0.76%[8].According to their malignant potential, SMTs can be classified into those with malignant potential including glomus tumors, carcinoids and gastrointestinal stromal tumors (GISTs), and those without malignant potential, including mesenchymal tumors, lipomas, leiomyomas, schwannomas, desmoid tumors, duplication cysts,pancreatic rests, and giant cell tumors[9]. The histopathological types of SMTs are complicated, but most are benign tumors, and less than 15% of SMTs appear to have malignant potential[10]. Leiomyoma is the most common SMT in the esophagus,accounting for 2/3 of benign esophageal tumors[11]. The stomach is the most common site for SMTs and the pathological types of stomach SMTs are even more complicated.GISTs, leiomyomas and pancreatic rests are also common in the stomach. Lipoma is the most common pathological type in the colon, while neuroendocrine tumors are most commonly found in the rectum[12].

Laboratory examinations

We report the case of a 47-year-old woman, who presented with upper abdominal discomfort for one year, and was subsequently diagnosed with a gastric submucosal lesion caused by an embedded foreign body by EUS and computed tomography. Considering the size and potential complications of this lesion,endoscopic full-thickness resection was performed to achieve full resection in our endoscopy center. A fish bone was found in the lesion during the operation, and was successfully removed, and the defect was later closed with endoscopic pursestring sutures.

Imaging examinations

Gastroscopy and colonoscopy were performed in our endoscopy center after hospitalization. A submucosal lesion 11.1 mm in diameter was found in the gastric antrum by gastroscopy (Figure 1A). As this lesion originated from the submucosa layer,endoscopic ultrasonography (EUS) was carried out to further evaluate this lesion. The EUS results revealed a low echo of the submucosal mass-like lesion (7.2 mm × 11.1 mm) in the gastric antrum, which may have originated from the muscularis propria layer. It was also revealed that the mucosal layer of the lesion was mildly thickened;the boundaries and the serosa remained clear and basically continuous. In addition, a point-like hyperechoic image accompanied by a posterior sound shadow was detected by EUS (Figure 1B). An abdominal computed tomography (CT) scan was conducted to further confirm the relationship between the lesion and adjacent abdominal organs.Interestingly, the CT scan revealed a hyperdense linear structure in the gastric antrum wall, suggestive of a FB, which did not penetrate the serosa layer, and tissue edema,enlarged lymph nodes and exudation were not observed (Figure 1C).

FINAL DIAGNOSIS

However, the accidental ingestion of a fish bone mimicking a stomach SMT is rare.EUS is currently the most accurate diagnostic tool for evaluating SMTs in the digestive tract. It also plays an essential role in delineating histologic layers and providing key information for doctors when choosing therapeutic methods in patients with SMTs[13,14]. Previous studies have shown that the sensitivity and specificity for distinguishing different types of SMTs are 64% and 80%[15], and for SMTs with a diameter less than 2 cm, EUS is superior to CT and magnetic resonance imaging (MRI)[16]. However, EUS has several technical deficiencies. By contrast, CT is an efficient and convenient tool for diagnosing FBs embedded in the gastrointestinal tract. Data from multiple studies demonstrate that the sensitivity and specificity of CT in identifying impacted fish bones were 90.9%-100% and 100%, respectively[17,18]. The CT images of a fish bone usually appear as a calcified structure[19], and a linear calcified structure was shown on the CT images in our patient (Figure 1C), which is consistent with a previous report[20]. Therefore, EUS combined with other imaging examinations such as CT or MRI are often used to enhance diagnostic accuracy. Furthermore, doctors can also obtain detailed information on the relationship between the tumor and surrounding blood vessels or organs using CT or MRI, which is helpful in planning therapeutic strategies.

TREATMENT

Endoscopic full-thickness resection (EFTR) was performed in order to achieve full resection. During the operation, a fish bone was found in the lesion (Figure 1D), and the lesion then was completely resected. The defect was subsequently closed with endoscopic purse-string sutures. An indwelling stomach tube was placed after endoscopic surgery. In order to prevent postoperative complications, intravenous nutrition, proton pump inhibitors and anti-infection drugs were also prescribed in this patient. The stomach tube was removed 48 h later and a liquid diet was prescribed for 72 h.

OUTCOME AND FOLLOW-UP

On the fourth day after surgery, the patient was in a stable condition and no discomfort or abnormalities were reported. She was then discharged from hospital. No discomfort was reported at the 30-d follow-up visit.

DISCUSSION

納入標準:(1)能生活自理的0級糖尿病足患者。(2)能順利溝通,知情且同意參與。排除標準:(1)糖尿病酮癥,急性感染,足部感覺異常。(2)下肢血管手術后及功能障礙。

Gastric submucosal lesion caused by an embedded fish bone.

Safe treatments to remove submucosal lesions caused by FBs are essential. Data from the European Society of Gastrointestinal Endoscopy clinical guideline indicated that approximately 80%-90% of ingested FBs can pass through the digestive tract spontaneously, and the remaining 10%-20% require endoscopic interventions[21]. A case from Brazil reported that an elevated lesion was found in the gastric antrum andmimicked a GIST. The lesion was immediately removed by exploratory laparotomy and a chicken bone was found in the lesion, which had penetrated the gastric wall and into the left lateral segment of the liver[22]. This suggests that FBs embedded in the digestive tract have the potential for perforation. In a few similar reports, endoscopic submucosal dissection (ESD) was used to remove FBs. As summarized in Table 1,treatment including ESD, surgery and regular follow-up varies depending on the patient’s condition[23-25]. With the development of novel endoscopic techniques, the removal of FBs is no longer restricted to surgery. Endoscopic surgery is a better option due to the advantages of fewer hospitalized days and less invasiveness. According to previous literature, ESD is a commonly used endoscopic intervention for the removal of FBs[26-28], which avoids the need for surgical exploration. However, when choosing endoscopic treatments, the status of patients and location of the FB should also be considered. In the present report, given the chronic abdominal discomfort in this patient and the potential for severe complications, we therefore performed EFTR for complete resection.

In summary, a gastric submucosal lesion caused by an embedded fish bone is uncommon in daily medical practice. Therefore, the possibility of embedded FBs should also be considered when trying to identify the cause of submucosal lesions or unexplained abdominal discomfort. The diagnosis of submucosal lesions mainly depends on EUS or CT. Traditionally, surgery is the main approach for the removal of an embedded fish bone if this FB cannot be observed under endoscopy. However,endoscopic surgery is becoming feasible with the maturity of novel techniques such as ESD and EFTR. During the follow-up period, EUS is superior to endoscopy due to its ability to delineate FB location, size and histologic layers. Moreover, EUS combined with other imaging data or abdominal examinations (CT/MRI) may also be necessary.Effective treatments are needed when this rare disease is highly suspected.

CONCLUSION

A submucosal lesion caused by an embedded fish bone is an exceptional condition.With the help of endoscopy, EUS and CT, the diagnosis of a FB is not difficult.However, difficulties arise when accurately locating the FB and conducting safe and effective treatment to remove it, especially in an urgent situation. EUS and CT are useful tools in the diagnosis of FBs in the gastrointestinal tract. At present, endoscopic surgery is the first-line treatment in this situation. This study demonstrates that being familiar with diagnostic methods and conducting effective treatment are essential when this rare condition is highly suspected.

在使用光學取景器拍攝時，D500和其他單反相機一樣，使用一塊專用的相位對焦傳感器進行對焦。這塊名為Multi-Cam 20K的傳感器是尼康最先進的型號，總共擁有153個對焦點，其中99點為十字型對焦點。

世界范圍內資本賬戶開放的浪潮大致經歷了80年代各國爭相放開，90年代發展中國家陸續發生貨幣危機從而產生質疑，再到目前注重時序性和漸進性政策三個階段。歷史經驗表明，資本項目開放的收益多體現在發達國家，而較少見諸發展中國家，而一些經濟、金融欠發達的中小發展中國家，往往因為缺少資本管制的屏障保護而成為國際投機資本攻擊的犧牲品。因此，如何充分享受資本項目開放的收益成為政策面臨的重大挑戰。前國際貨幣基金組織總裁Camdessus提出，亞洲金融危機的根源在于既定的宏觀經濟環境和制度背景下，資本項目開放措施與經濟金融等改革的銜接出現了問題[1]。

We appreciate all the medical staff in our endoscopy center involved in the treatment of this patient.