Sarcina as an Unknown Culprit of Esophageal Strictures

Abstract

Sarcina ventriculi is a gram positive organism that is well known to veterinarians, however the exact pathogenicity in humans is not well delineated. Several cases of human disease have been described including emphysematous gastritis, gastric ulcers and perforation, and recently esophageal pneumatosis. Here we present a case of Sarcina-associated esophageal stricture. A 65 year old woman with metastatic breast cancer and history of Schatzki ring presented with two months of progressive dysphagia. Imaging with x-ray fluoroscopy revealed an irregularly short segment stricture at the mid to distal esophagus. Esophagogastroduodenoscopy (EGD) showed a benign appearing stenosis at 32 cm that measured 3 mm in diameter and gastric ulcers. She underwent subsequent dilation under fluoroscopy with a Savary dilator up to 12 mm and was medically managed with a proton pump inhibitor. Esophageal biopsies revealed acute and chronic inflammation with rare large tetrads of bacterial cocci, morphologically consistent with Sarcina organisms. In light of Sarcina presence, she was treated with 7 days of metronidazole and ciprofloxacin. An esophageal stent was placed after serial dilation failed to improve symptoms. Unfortunately, her hospital course was complicated by acute pulmonary embolisms, hemorrhagic gastropathy, and persistent vomiting resulting in subsequent removal of the stent. Ultimately, the patient transitioned to palliative comfort care due to overall poor prognosis. Sarcina ventriculi is a well described pathogen in veterinary medicine, but its role in human disease is not as well understood. Human presentation has varied widely from gastrointestinal symptoms of nausea, vomiting, epigastric pain to emphysematous gastritis complicated by gastric perforation. EGD findings have also varied but common themes have emerged including luminal findings of retained food residue and mucosal findings of erosion and gastric ulcers. While most reported cases of Sarcina pathology have been gastric in location, very few have been esophageal. Studies of the esophageal microbiome did not identify Sarcina in patients with normal histology, which suggests that in contrast to gastric sites the organism is more likely to be a pathogen. Compared to previous esophageal pathology reported, we report a case of Sarcina that occurred in the setting of stasis as a result of esophageal stricture. It will be important to further assess the importance of Sarcina in the pathogenesis of esophageal diseases.Figure: EGD findings of severe esophageal stricture.Figure: Purple Sarcina cocci in characteristic tetrads (long arrows) are present in the luminal aspect of this gastric biopsy. Notice the large size of the organisms in comparison to the luminal bacilli (arrowheads) in the background. There is mild acute inflammation, demonstrated by the intraepithelial neutrophils (short arrows), in the adjacent gastric epithelium. Hematoxylin and eosin (H&E) stain, original magnification 600x.Figure: Esophagus squamous mucosa with luminal Sarcina organisms (long arrows). Arrowhead points to background bacilli for size comparison. H&E 600x.