1730 Esophageal Actinomycosis in a Patient With Long-Standing Esophageal Stent

Abstract

INTRODUCTION: Actinomyces is a commensal in aero-digestive tracts which rarely causes infection. The commonest site is cervicofacial region. Risk factors are low immunity and pre-existing tissue damage. Esophageal involvement is rare. We report a case of esophageal actinomycosis in an immunocompetent patient. CASE DESCRIPTION/METHODS: A 71-year-old male presented with recurrent dysphagia. The patient had multiple prior EGDs for management of refractory peptic stricture due to gastrin secreting pancreatic neuroendocrine tumor. He undewent multiple prior procedures with placement of fully-covered self-expanding metal stents (SEMS) for therapy of refractory stricture, as surgical esophagectomy was not possible due to co-morbidities and patient preference. On previous EGD, one of the stents could not be removed due to tissue ingrowth at the distal end, and another SEMS was placed overlapping the imbedded stent and extending to the gastric cardia. The patient was lost to follow up for 7 months until presenting with recurrence of dysphagia. EGD now showed proximal migration of the distal stent with severe stenosis, inflammation, and nodularity distal to the esophageal stents. The distal stent was imbedded in the abnormal mucosa and could not be removed. Following balloon dilation another SEMS was placed in the distal esophagus. Pathology revealed ulcerated acute esophagitis with actinomycetes colonies. The patient was placed on a long course of IV penicillin-G. At subsequent EGD a month later, the tissue ingrowth improved allowing removal of the esophageal stents. Repeat biopsies did not reveal actinomyces. DISCUSSION: Actinomyces, a gram positive anaerobic rod, is unable to penetrate healthy tissue. It requires mucosal compromise to invade tissue, leading to abscess and sinus formation across tissue planes. Our patient had multiple risk factors - mucosal damage, endoscopic dilations and stenting. Esophageal stent in situ for longer than 3 months increases the risk of embedment. Discovery of esophageal ulceration or tissue ingrowth in this setting should raise suspicion for possible actinomycosis (among other diagnoses) and biopsies should be obtained. Gram stain and histology would reveal necrosis with yellow sulfur granules and gram-positive filamentous pathogen. Early diagnosis is necessary to initiate treatment in a timely manner to prevent the potentially debilitating sequelae of chronic infection. Treatment includes penicillin G or amoxicillin for 3-12 months.