There is a small nodule in the esophagus ( food pipe) not the small intestine. There is also a small nodule on lung. CT scan cannot give information on what type of nodule it is. For that your father will need to undergo an upper GI/ Esophago-gastroscopy with a biopsy of nodule.
Next Steps
Please visit a gastroenterologist who will perform the Endoscopy, take a biopsy of the nodule and send it for histopathological examination.
Health Tips
please get it done at the earliest