Esophageal actinomycosis is an extremely rare condition, with very few cases published in the literature. The vast majority manifest as ulcers or erosions in the esophageal mucosa mimicking an esophageal tumour.1
We present the case of a 76-year-old woman with a history of antireflux surgery by Nissen fundoplication in 2014. She attended our clinic in September 2021 with a 15-day history of progressive dysphagia for solids and liquids, with no associated constitutional symptoms. Lab tests showed only elevation of C-reactive protein up to 50, with no other findings. Her physical examination was unremarkable.
An upper gastrointestinal endoscopy was requested and she was started on a puréed diet until investigations could be completed. Four days later, the patient went to Accident and Emergency because of oral intolerance. Upper gastrointestinal endoscopy showed some difficulty in passage at the level of the lower esophageal sphincter. In retroversion, it was possible to see the sutures from the earlier fundoplication with a slight foreign body reaction; the area was biopsied with results suggesting non-specific inflammation. There were no signs of lesion in the esophageal mucosa.
The patient was admitted to the hospital ward for investigation. A barium swallow was performed, demonstrating an image compatible with achalasia-pseudoachalasia. Tests were completed with a chest/abdomen computed tomography scan, which revealed circumferential thickening of the distal middle third of the esophagus with lymphadenopathy, suggesting malignancy as the top possibility. An endoscopic ultrasound was then performed in which it was not possible to access the stomach. Esophageal thickening was seen which included all layers, in addition to peri-esophageal fat and lymphadenopathy, raising suspicions of malignancy. The area of thickening was punctured, but the samples were insufficient. As we needed a histological sample, the endoscopic ultrasound was repeated. This time a 4 cm segment was described with normal stenotic mucosa with a 1 cm thickening with hypoechoic fraying towards mediastinal fat, with the muscularis propria appearing to be normal. There were several benign-looking enlarged lymph nodes in the vicinity. On this occasion, the endoscopist interpreted the image as thickening with inflammatory, benign characteristics. A biopsy was taken from the thickened area for cytology. The results came back negative for malignancy, with the finding of sulphur granules suggestive of the presence of actinomyces.
With this diagnosis, the immunosuppression study was completed with serology and detailed medical history but without any findings. The patient was started on treatment with intravenous penicillin G for three weeks. After that period, the patient made good progress, being able to ingest solids, and her C-reactive protein levels returned to normal. As the initial suspicions were highly compatible with malignancy, endoscopic ultrasound was repeated after the three weeks of intravenous antibiotic therapy. This time, it was possible to access the stomach with the ultrasound-guided endoscope, verifying a decrease in the thickening and a reduction in the size of the lymphadenopathy. The patient completed treatment with a six-month course of oral amoxicillin.
Actinomyces is a Gram-positive, facultatively anaerobic bacillus. It is a commensal microorganism of the flora of the mouth and gastrointestinal tract. They are slow-growing bacteria which can cause purulent abscesses in infected tissues. Esophageal involvement is usually preceded by a disruption of the mucosa which allows the entry of the bacteria. This disruption can occur after surgical or endoscopic mucosal trauma, even years after the event.1
Clinically it tends to present as odynophagia and dysphagia. It is slightly more common in males than in females. It has a higher prevalence in immunosuppressed patients, but cases have been reported in immunocompetent patients.2 Endoscopically, esophagitis, ulcers and esophageal mass have been described.
This was a particularly interesting case. She was the first reported case of esophageal actinomycosis presenting with circumferential esophageal thickening without mucosal lesions. And ultimately, she was an immunocompetent patient, significantly reducing the degree of suspicion for the diagnosis.
Diagnosis is challenging, as the histological identification of the bacterium is only possible in very few patients. Microscopic examination is essential and typically shows necrosis and sulphur granules. Treatment consists of administering intravenous penicillin for two to four weeks, followed by oral amoxicillin for approximately six months.3
