Gastric pseudo-obstruction as an initial manifestation of thymoma

Abstract

TO THE EDITOR:Thymomas and thymic carcinomas are rare, accounting for 20% of all mediastinal tumors. They are usually diagnosed as incidental findings on chest imaging performed for another reason or performed because of the presence of mass effect-related symptoms or paraneoplastic syndrome, such as myasthenia gravis. They have similar incidence in men and women and most commonly occur in the 40-to 60-year age group. There are no risk factors. (1,2) We would like to present the case of a 79-year-old female patient who presented to our facility with a two-month history of weight loss and constipation. She was admitted to the hospital with signs of intestinal obstruction, abdominal bloating, and vomiting. A nasogastric tube drained 3,000 mL of stool-like secretion. Abdominal X-ray and ultrasound revealed a dilated stomach with an air-fluid level ( Figures 1A and 1B). Upper gastrointestinal endoscopy revealed no points of mechanical obstruction; there was erosive reflux esophagitis, exuberant gastric dilatation associated with gastric stasis, and hypertrophic pyloric stenosis. Serology for Chagas disease was negative.The assessment continued with abdominal CT, which showed no evidence of any obstructive factor or tumor, and chest CT, which identified a well-demarcated anterior mediastinal mass with a maximum diameter of approximately 5 cm and no invasion of adjacent structures ( Figure 1C). Given the possibility of paraneoplastic syndrome, video-assisted thoracoscopic resection was performed, and pathological examination showed small cell neoplasm of uncertain malignant histogenesis and immunohistochemistry, confirming the diagnosis of type B1 thymoma.Following tumor resection, the patient experienced a lower frequency of vomiting and was able to tolerate the diet. Gastrography was performed which showed contrast progression and a normal-sized stomach with peristalsis ( Figure 1D). A second endoscopy revealed a normal stomach with strong peristaltic waves and no sign of previous hypertrophic pyloric stenosis. The patient was discharged on an oral diet. Serum antibody testing for myasthenia gravis and paraneoplastic syndrome was ordered.Gastroparesis consists of delayed gastric emptying of solids in the absence of mechanical obstruction. The A B C D Figure 1. In A and B, abdominal X-ray showing gastric bloating. In C, CT scan showing a well-demarcated anterior mediastinal tumor. In D, gastrography showing normal gastric emptying.

Autoimmune disorders and paraneoplastic syndromes in thymoma

“…Autoantibodypatterns include VGKC as well as neuronal AChR as targets. Prokinetic agents (i.e., pyridostigmine) and immunosuppressive therapies (corticosteroids, intravenous immunoglobulins) were utilized (85)(86)(87)(88)(89).…”