Gastric Adenomyoma: Salient Imitator

Abstract

Abstract Introduction/Objective Gastric adenomyoma is a lesion characterized by proliferation of epithelium and smooth muscle in the stomach or small bowel. By ultrasound, gastric adenomyoma usually appears as a submucosal nodule with a cystic center. They can mimic many benign and malignant conditions and are an important differential diagnosis to consider in fine needle aspiration of submucosal upper gastrointestinal lesions. Methods/Case Report We present a 30-year-old male who presented with abdominal pain, dyspepsia, and heartburn. Esophagogastroduodenoscopy demonstrated a 10 mm well-circumscribed hypoechoic mass in the antral submucosa along the greater curvature of the stomach. Two years later, the lesion was 18.6 mm in greatest dimension and fine needle aspiration was performed. Cell block showed foci of benign gastric glands and bland smooth muscle tissue, positive for smooth muscle actin and desmin, and negative for CD34 and c-kit (CD117). Gastrointestinal stromal tumor was the main differential diagnosis and adenomyosis was not considered, thus, the biopsy was thought to represent normal gastric wall, and the glands were dismissed as contaminant from the aspiration. A subsequent ultrasound two years later again demonstrated the lesion, now 21.5 mm in greatest dimension, and definitive resection was performed. Histologic examination showed a segment of stomach with gastric antral-type mucosa and an underlying mass forming lesion consisting of scattered gastric type glands admixed with smooth muscle bundles, consistent with gastric adenomyoma. The glands were completely surrounded by smooth muscle and lamina propria. Our patient has been asyptomatic one year since resection of the gastric adenomyoma. Results (if a Case Study enter NA) NA Conclusion Gastric adenomyoma is an important differential of intramural spindle cell neoplasms of the gastrointestinal tract alongside many benign and malignant conditions. Consideration of gastric adenomyoma at the time of the original biopsy would have spared the patient uncertainty regarding their prognosis and allowed for definitive resection two years earlier.