Gastric bronchogenic cyst pooled case analysis: a case report and systematic review.

Introduction
Bronchogenic cysts (BCs) are a rare idiopathic disease characterized by pre-embryonic intestinal malformation [1], which have an estimated incidence rate ranging from 1 in 68,000 to 1 in 42,000 [2]. BCs are classified into three types: mediastinal, intrapulmonary, and ectopic, among which the ectopic type is the rarest [3].
Gastric bronchogenic cysts (GBCs), a distinct subtype of ectopic BCs, were first reported by Dewing et al. in 1956 [4]. The pathogenesis remains incompletely understood. Current evidence suggests that during early embryonic development, the thoracic and abdominal cavities communicate through the pleuroperitoneal canal. Subsequent fusion of the pleural and peritoneal membranes, as part of diaphragm formation, normally separates these cavities. In the context of BCs, it is hypothesized that abnormal buds of the tracheobronchial tree become detached and ectopically migrate to the stomach [5].
The pathogenesis of GBCs is unclear but may involve ectopic migration of tracheobronchial precursors. While often asymptomatic, they become symptomatic due to complications like enlargement, compression, infection, or perforation. Diagnosis primarily relies on CT and MRI; however, nonspecific imaging features contribute to high misdiagnosis rates ranging from 40% to 60% [2, 6].
Surgical resection remains the cornerstone of management for GBCs, though no standardized approach has been established across studies [7]. Most patients achieve favorable outcomes [8]. Current evidence predominantly relies on case reports with significant individual variability and a lack of high-level evidence. Therefore, we conducted a systematic review of GBCs to analyze their clinicopathological and radiological features, treatment options, and prognostic differences, aiming to better inform clinical decision-making.

Methods
This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [9] and registered in the PROSPERO database (CRD420251249068) (Supplementary file 1). The study protocol was approved by the Ethics Committee of Peking University People’s Hospital, Beijing, China (Approval No.2024PHB369-001) and adheres to the principles of the Declaration of Helsinki (Supplementary file 2).

Search strategy
Two investigators systematically searched PubMed, Embase, Cochrane Library, Web of Science, and Scopus up to 18 November 2025 to identify GBC-related studies. The search strategy combined MeSH terms (or database-specific controlled vocabulary) and free text terms for “bronchogenic cyst” and “stomach/gastric region” (detailed strategies in Supplementary file 3). Additionally, a secondary literature search and manual citation checking of all included studies were performed to retrieve eligible early case reports not captured by electronic database searches due to historical diagnostic terminology variations.

Study selection and criteria
Two investigators screened titles and abstracts to exclude irrelevant studies; full texts of remaining studies were assessed by the same reviewers for eligibility. Discrepancies were resolved via consultation with a third reviewer.
Exclusion criteria: (1) Non-English literature; (2) Lack of pathological confirmation; (3) Duplicate case reports; (4) Unavailable full text.
Inclusion criteria: (1) Patients with definite pathological diagnosis of gastric bronchogenic cyst; (2) Study type: case reports and case series. Case reports published as meeting abstracts were also included if they contained sufficient clinical and pathological details to meet the above criteria.

Data extration
Two investigators independently extracted data from eligible studies using a predefined form. Collected data included sex, age, symptomatology, medical history, cyst location, diagnostic modality, treatment approach, pathology, and follow-up. Controversies were resolved by a senior investigator.

Quality assessment
Included studies’ methodological quality was assessed using JBI Critical Appraisal Checklists (for case reports and case series). Two investigators performed assessments; discrepancies were resolved by consensus, with a third senior reviewer consulted if necessary to ensure objectivity. The JBI tools addressed selection, information, and reporting biases, evaluating core elements (data validity, follow-up completeness, reporting transparency). Items were rated as “yes,” “no,” “unclear,” or “not applicable”; studies were categorized as high/moderate/low quality based on satisfied items, with low-quality studies undergoing sensitivity analysis. Assessment results are presented in Supplementary file 4.

Data analysis
Numerical variables are reported as mean ± standard deviation, and categorical variables as frequencies and valid percentages. Patients from case series were treated as unique cases to analyze target variables. Due to incomplete data in some studies, rates were calculated using available information. Statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 27.0 (IBM Corp, Armonk, NY).

Results

Case report
In September 2025, a 53-year-old female was admitted to our hospital due to intermittent epigastric distension and pain combined with acid reflux 1 month as the chief complaint. Gastroscopy showed no evidence of erosion or ulceration. Contrast-enhanced CT of the upper abdomen revealed a soft tissue density lesion adjacent to the aorta, located on the medial aspect of the gastric fundus (Fig. 1A). This lesion exhibited well-defined margins, a cross-sectional dimension of approximately 36 mm × 20 mm, and local adherence to the gastric wall, with no significant enhancement on contrast imaging. Electronic endoscopic ultrasonography (EUS) detected no blood flow signal. Following multidisciplinary team (MDT) discussion, the preoperative diagnosis was highly suspicious for a submucosal gastrointestinal stromal tumor (GIST). Considering the special location of the lesion and associated risks, preoperative EUS-FNA was not performed. And the patient underwent laparoscopic exploration. A well-encapsulated tumor was identified anterior to the abdominal aorta, and near the esophageal hiatus. The intraoperative diagnosis was consistent with a retroperitoneal tumor. Laparoscopic resection of the retroperitoneal tumor was performed.​

Postoperative pathology revealed a cystic wall-like lump, with the cyst wall lined by cuboidal and ciliated columnar epithelium (Fig. 1B-D). A thin layer of smooth muscle components was noted in focal areas of the cyst wall, with secretion retention within the cyst, which indicated a diagnosis of bronchogenic cyst.​

Pooled case analysis

Demographic characteristics
This pooled analysis included 48 GBC patients, consisting of 45 eligible studies[1–8, 10–20, 23–48] and our newly reported case (44 case reports and 2 case series). There were 30 females (62.5%) and 18 males (37.5%), with a male-to-female ratio of 1:1.67. The mean age of the cohort was 47.54 ± 15.83 years. The study selection flowchart is presented in Fig. 2.

Clinical characteristics
Abdominal pain, which was mostly epigastric, was the most common symptom (22 cases, 45.8%), while 31.3% of patients (15 cases) were asymptomatic and diagnosed incidentally. Anatomically, GBCs were most frequently located in the gastric fundus (16 cases, 33.3%) and cardia (13 cases, 27.1%), followed by the gastric body (4 cases, 8.3%). Remaining cases were predominantly distributed in the gastric posterior wall, greater curvature, or lesser curvature (specific locations not fully reported). Detailed information on individual characteristics, cyst location, preoperative diagnosis, treatment, and follow-up is summarized in Table 1.

Imaging and laboratory characteristics
A total of 42 patients underwent CT examination: 18 were misdiagnosed as gastrointestinal stromal tumors, and 9 as other cysts. The density of cyst contents was unreported in over half of the cases; among available data, most showed hypodense lesions without contrast enhancement (15/17). MRI findings (3/3 cases) were consistent with hypointense or isointense signals on T1-weighted imaging (T1WI) and hyperintense signals on T2-weighted imaging (T2WI). Eight patients had abnormal tumor marker elevations (4 with CA199, 3 with CA724, 1 with CEA), all of which returned to normal after surgical resection.

Treatment characteristics
Preoperative definitive diagnosis of GBC was achieved in only 3 cases. Forty-five patients underwent surgical resection combined with pathological confirmation: open surgery (35.4%), laparoscopic surgery (50.0%), endoscopic resection (4.2%), and 3 cases with unspecified surgical approaches. Two patients received conservative treatment: one via gastric body biopsy [15] and the other via endosonographically guided fine-needle aspiration (EUS-FNA) [17], both confirming characteristic GBC cellular structures. Pathologically, pseudostratified ciliated columnar epithelium (PCCE) surrounding smooth muscle was the most common type (56.3%), with 14 cases accompanied by serous or mucous glands.

Follow-up characteristics
Prognostic information was available for 34 patients: 32 surgical patients recovered and were discharged successfully, and 21 had complete follow-up data (mean duration 10.38 ± 8.25 months). All symptomatic patients achieved symptom relief postoperatively; no recurrence, metastasis, or malignant progression (including in the conservative treatment case) was observed. Comprehensive data on demographic, clinical, preoperative, pathological, and prognostic features are summarized in Table 2.

Discussion
Gastric bronchogenic cyst is an extremely rare ectopic congenital lesion, with clinical evidence historically limited to scattered case reports and a lack of systematic synthesis of its key clinicopathological and therapeutic features. To address this gap, we conducted a pooled analysis integrating one newly reported case and 47 literature-derived cases to comprehensively characterize GBC. Our findings highlight that GBC predominantly affects females with a predilection for the gastric fundus and cardia, presenting with nonspecific abdominal pain or being incidentally detected. Notably, the preoperative misdiagnosis rate is remarkably high (predominantly as gastrointestinal stromal tumors), with typical radiological features of a well-circumscribed, non-enhancing hypodense cyst. Surgical resection is the preferred treatment, and the overall prognosis is favorable with no reported recurrence or malignant transformation. This study organizes fragmented evidence into a structured summary, supplementing limited high-level data and providing preliminary references to assist with the diagnosis and management of this rare disease.
Females appear more predisposed to GBC. Relevant studies on mediastinal and branchial cleft cysts—embryonically similar epithelial residual cysts—have identified high estrogen receptor (ER) expression in female patients and noted that pregnancy enhances ERα expression to promote cyst growth [48, 49]. This estrogen-dependent hypothesis may explain the gender disparity in GBC, but evidence remains limited by small sample sizes. Larger cohorts are needed to verify the underlying mechanism.
Diagnosing GBC is clinically challenging, with preoperative diagnosis relying mainly on CT and MRI. On CT, GBC typically presents as an isolated, well-circumscribed, homogeneous hypodense mass without significant enhancement; approximately half of reported cases have cyst fluid attenuation < 20 HU, while higher values may occur due to protein accumulation, hemorrhage, infection, or calcification [5, 23, 29, 41]. MRI shows hypointense or isointense signals on T1WI and hyperintense signals on T2WI [32]. The misdiagnosis rate of GBC is 40–60% in previous reports [2, 44], and only 3 patients were correctly diagnosed preoperatively in our study, whose rate potentially inflated by publication bias. GBC is difficult to distinguish from GISTs and gastric foregut duplication cyst (FDC): GISTs share overlapping CT and MRI signal features [50], while FDCs, being another congenital cystic lesion, are indistinguishable from GBC on clinical and imaging grounds, with the only differentiator being the absence of cartilaginous and glandular tissues in FDC pathology [51].
EUS-FNA has shown positive diagnostic value for GBC [2, 5, 7, 17, 20, 25, 29, 38, 41], with a sensitivity of 93–95%, diagnostic accuracy of 82–86%, and low adverse event rate (1–3%). However, its application requires careful risk-benefit assessment due to GBC’s predilection for the gastric fundus and cardia, which is sometimes adjacent to vital tissues and major blood vessels. Inappropriate puncture may cause severe complications such as hemorrhage, vascular injury [52], and false negatives can occur in small cysts due to failed sampling [20, 28, 45]. Thus, postoperative histopathological examination remains the gold standard: GBC is confirmed by bronchial epithelial components such as PCCE, with or without smooth muscle, glands, or cartilage [3, 8, 12, 31, 32, 41, 44]. Immunohistochemically, CK7 positivity combined with CK20 negativity supports the diagnosis, while TTF1/NapsinA co-expression confirms a bronchial origin [3, 36].
Surgical resection is recognized as an effective treatment for GBC [2, 29, 37, 42], but optimal indications remain debated [7, 27, 29]. Surgery is recommended for suspected malignancy, symptomatic cases, or complications (infection, rupture, compression and so on) [2, 7, 27, 29], while conservative follow-up with endoscopic surveillance is proposed for small, asymptomatic lesions [7, 25, 29, 38]. Although one asymptomatic case in our cohort remained non-malignant during follow-up, long-term studies have reported a 45% symptom development rate and 0.7% malignant transformation risk in asymptomatic bronchogenic cyst patients [53, 54]. Due to limited high-quality follow-up data, no standardized consensus exists for GBC management, and larger studies are needed to clarify this dilemma.
Several limitations of this study warrant acknowledgment. First, GBC’s rarity restricted the number of eligible cases, limiting statistical power and generalizability. Second, individual participant data (IPD) analysis was not feasible due to the limited availability of raw data from most included studies. Third, methodological biases exist: inclusion of only English-language and full-text accessible articles may exclude relevant research, and publication bias (preference for symptomatic/surgically treated cases) may skew results. Fourth, substantial data incompleteness—such as missing imaging details (59.5% of cases), tumor marker data (50.0%), immunohistochemical results (83.3%), and follow-up information (54.2%)—introduces information bias and hinders comprehensive prognostic analysis.

Conclusion
In conclusion, gastric bronchogenic cyst is a rare and diagnostically challenging congenital abnormality with limited evidence to guide preoperative diagnosis. It should be incorporated into the differential diagnosis of gastrointestinal neoplasms. Surgical resection is regarded as the effective approach for definitive diagnosis treatment.

Supplementary Information