S3613 Gastric Spindle Cell Leiomyosarcoma Is Associated With Chronic Helicobacter pylori Infection

Abstract

Introduction: Chronic Helicobacter pylori (HP) infection has been shown to be strongly associated with development of gastric malignancies, mostly gastric adenocarcinomas and lymphomas. We present a case of primary gastric leiomyosarcoma in a patient with persistent epigastric pain and HP infection. Case Description/Methods: A 59-year-old female presented to clinic with persistent, postprandial epigastric pain. Cardiopulmonary workup was negative. She had a history of esophageal leiomyoma resected endoscopically with negative margins 10 years ago. She was treated in the past for HP infection but never had repeat testing to confirm eradication. Abdominal computed tomography showed focal hepatic infiltration. She was advised to have a repeat upper endoscopy for surveillance but was lost to follow-up due to psychiatric comorbidities. She presented 6 years later with epigastric pain. Repeat CT abdomen showed a new 2.8 cm hypoattenuating lesion in the lesser curvature of the stomach. Patient did not follow up due to psychosocial issues. Two years later, she returned to clinic for epigastric pain and underwent repeat upper endoscopy and endoscopic ultrasound (EUS) with fine needle aspiration (FNA). EGD showed sub-gastric nodule attached gastric wall, about 30 mm in maximal dimension and gastric biopsy confirmed active HP infection. The EUS showed a 31.7x23.5 mm hypoechoic homogeneous gastric mass along the lesser gastric curvature. Cytology showed cellular spindle cell neoplasia with myogenic differentiation concerning for possible leiomyoma or leiomyosarcoma. Abdominal magnetic resonance imaging and chest computed tomography revealed no evidence of abdominal or thoracic metastasis. Subsequently, partial underwent sleeve gastrectomy. Pathology revealed Grade 1 myxoid leiomyosarcoma with negative margins. (Figure) Discussion: Prior studies demonstrated associations between HP infection and gastric malignancies - typically gastric adenocarcinoma or lymphomas. Few studies investigated the relationship between HP infection and gastric leiomyosarcomas.4,5 Importantly, this patient never had clearance of HP infection and may have allowed a leiomyosarcoma to develop. It is imperative that clinicians confirm eradication of HP infection given risk of leiomyosarcoma development in addition to other malignancies HP infections are known to cause.Figure 1.: Endoscopic and histologic examination of gastric leiomyosarcoma. (A) Endoscopic ultrasound visualization demonstrating tumor within lesser curvature of stomach. (B) Upper endoscopy revealing tumor approximately 4 cm from gastroesophageal junction. (C) Hematoxylin and eosin (H&E) stain of gastric tumor biopsy demonstrating spindle cell proliferation in a myxoid background with significant nuclear atypia and pleomorphism consistent with myxoid leiomyosarcoma. Magnification x400. (D) Immunohistochemical staining of gastric lesion biopsy demonstrating strong immunoreactivity to desmin. Not shown are positive stains for smooth muscle actin (SMA) as well as negative stains for Cytokeratin AE1/AE3, Myogenin, MyoD1, DOG-1, CD117, S100, SOX10, CD34, ALK-1 and ER. Positive and negative controls stained appropriately but are not included.