Gastric Duplication Cyst With Occult GIST Component

Area of Science:

• Gastroenterology
• Surgical Pathology
• Diagnostic Imaging

Background:

• Submucosal tumors of the stomach require accurate diagnosis for appropriate management.
• Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the GI tract.
• Gastric duplication cysts are rare congenital anomalies that can present as submucosal lesions.

Observation:

• A 37-year-old man presented with a pale submucosal tumor in the gastric cardia.
• Endoscopic ultrasound revealed a 15-mm cyst with hypoechoic nodules in the muscularis propria.
• Fine-needle aspiration cytology showed atypical spindle cells positive for c-kit, suggestive of GIST.

Findings:

• Despite initial suspicion of GIST, the resected lesion was histologically confirmed as a gastric duplication cyst.
• The cyst measured 22 × 22 × 15 mm and was located in the muscularis propria.
• No evidence of gastrointestinal stromal tumor was found on final pathological examination.

Implications:

• This case underscores the diagnostic challenges in differentiating GIST from gastric duplication cysts using endoscopic ultrasound and fine-needle aspiration.
• Gastric duplication cysts, though rare, can have malignant potential and require careful follow-up or resection.
• Accurate histological diagnosis is crucial for determining the optimal management strategy for gastric submucosal lesions.