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Gastric duplication cyst (GDC) lined by pseudostratified columnar ciliated epithelium (PCCE) is an uncommon lesion stemming from a foregut developmental malformation. Its clinical and radiological presentation is usually nonspecific. In this study, we reported a 76-year-old man who presented with an incidentally found perigastric mass. An exploratory laparotomy revealed a non-communicating cyst below the gastroesophageal junction, measuring 4 cm×4 cm in size. Microscopically, the gastric cyst was lined merely by PCCE. Although rare, GDC lined by PCCE should be included in the differential diagnosis of gastric wall masses. Surgical intervention is warranted in patients who have clinical symptoms, or who are aged more than 50 years.
Gastric duplication cyst (GDC) is an uncommon congenital malformation and is usually lined by gastrointestinal mucosa. GDC lined by pseudostratified columnar ciliated epithelium (PCCE) is extremely rare, and only 17 cases have been reported up to Mar. 2010 (Table (Table1).1). Due to the nonspecific clinical and radiological presentation, GDC lined by PCCE is easily misdiagnosed as a gastrointestinal stromal tumor (GIST). In this paper, we describe a unique case of GDC lined merely by PCCE, and the available English literature is reviewed.
Summary of gastric duplication cyst lined by pseudostratified columnar ciliated epithelium
A 76-year-old man was referred to our hospital for evaluation of a perigastric mass found incidentally on abdominal ultrasonography. He had been in a good state of health. Physical examination findings and laboratory studies were within normal ranges. An abdominal computed tomography (CT) demonstrated a homogeneous, low-density mass, measuring 4 cm×4 cm, on the lesser curvature of stomach without contrast enhancement (Fig. (Fig.1).1). Gastroscopy revealed a submucosal type elevation with overlying normal mucosa below the gastroesophageal junction. Endoscopic ultrasound (EUS) showed this to be a hypoechoic lesion, arising within the tunica muscularis (Fig. (Fig.2).2). Preoperative diagnosis was a GIST and surgical excision was performed. The patient had an uneventful recovery and remained healthy to date.
Abdominal contrast-enhanced computed tomography (CT) scan demonstrating a homogeneous, low-density mass on the lesser curvature of the stomach (arrow)
Endoscopic ultrasound (EUS) showing a hypoechoic lesion, arising within the tunica muscularis (arrow)
Pathologic examination reported that the cyst was embedded within the gastric muscular layer, and did not communicate with the gastric lumen. Microscopically, the cyst wall was lined merely by PCCE, with two or three complete layers of smooth muscle bundles. However, cartilaginous tissue, seromucous gland, or gastric epithelium was not identified (Fig. (Fig.33).
Microscopic sections of the gastric duplication cyst
Gastric duplication cyst is an uncommon lesion that accounts for 2%–8% of all alimentary duplications (Kim et al., 2000). It is suggested that GDC lined by PCCE is derived from the caudad-most portion of the laryngotracheal outgrowth, which remains attached to the portion of the primitive foregut destined to become the stomach (Gensler et al., 1966), and migrates into the abdominal cavity before the fusion of the pleuroperitoneal membrane in the 7th week of gestation (Song et al., 2005). When PCCE is seen in a cyst, we designate those containing cartilage or seromucous respiratory glands as bronchogenic cysts, those containing two well-developed layers of smooth muscle without cartilage as esophageal cysts, and those without these distinguishing features as foregut cysts (Murakami et al., 2008). Moreover, it is advocated that the nomenclature for these duplicated cysts should involve the location as the prefix and the differentiation of the cyst suggested by the epithelium as the suffix (Sharma et al., 2009). Our present case includes none of those distinguishing features mentioned above. Therefore, we describe it as gastric duplication cyst with foregut differentiation.
GDC lined by PCCE is a late onset disease (from 25 to 76 years in age) with little difference between genders (10 women and 8 men). The most common location is on the lesser curvature, near the gastroesophageal junction. It is usually asymptomatic and is discovered incidentally as a gastric wall mass. However, some patients complain of epigastric pain which may be caused by compression on adjacent structures or ulceration due to the ectopic gastric mucosa in the cysts (Kim et al., 2000). Malignant change of GDC lined by PCCE is rare. Shibahara et al. (2009) reported a case of bronchogenic cyst of the stomach located at the opposite side wall to the gastric adenocarcinoma, and attributed the adenocarcinoma to the chronic inflammation from the bronchogenic cyst to the gastric mucosa. Worth mentioning, because of persistent exposure to carcinogenic substances, alimentary duplication cyst should be recognized as a lesion at risk for malignant transformation in patients aged more than 50 years (Fukumoto et al., 2008).
CT can detect the presence of abdominal mass, but it frequently fails to identify the cystic nature of the GDC lined by PCCE due to the thick, proteinaceous cyst fluid (Lee et al., 2006). EUS is helpful in identifying the intramural or extramural relation of the gastrointestinal tract (Eloubeidi et al., 2004). Moreover, EUS-guided fine needle aspiration (EUS-FNA) provides cytological diagnosis of the GDC. It is believed that the presence of detached ciliary tufts and absence of neoplastic cells confirm the benign nature of the cyst (Eloubeidi et al., 2004). In addition, 99Tcm-pertechnetate scintigraphy can diagnose ectopic functioning gastric mucosa, which is often associated with complications like ulceration in the GDC (Kumar et al., 2005). However, in our case, we misdiagnosed the mass as a GIST, which is much more common than a congenital cyst, and it is not advised to perform biopsy to confirm the diagnosis of a resectable GIST as it can lead to tumor dissemination or hemorrhage (Chaudhry and DeMatteo, 2009). Therefore, we failed to make an accurate diagnosis before operation.
The recommended management of symptomatic GDC is complete excision of the cyst without violation of the gastric lumen. If this is not possible, segmental gastrectomy is an alternative (Holcomb et al., 1989). When malignant change is seen in the cyst, a surgical procedure without rupture of the cyst is required (Shibahara et al., 2009). Management of asymptomatic cases remains controversial. Eloubeidi et al. (2004) suggested watchful waiting after confirming the benign nature of these cysts by EUS-FNA. However, considering the potential for complications and malignant change, we believe, for asymptomatic cases, surgical intervention is warranted in patients aged more than 50 years, especially when ectopic functioning gastric mucosa was detected.
In summary, GDC lined by PCCE is an uncommon lesion stemming from foregut developmental malformation. Its clinical presentation is usually nonspecific and it is easily misdiagnosed as a GIST radiologically. EUS-FNA can provide cytological diagnosis and confirm the benign nature of the cyst. Although rare, GDC lined by PCCE should be included in the differential diagnosis of gastric wall mass. Surgical intervention is warranted in patients with clinical symptoms, or who are aged more than 50 years.