pot grown citron
I have a citron pot grown for more than 5 years. I let it dry out, but it came back. There is a large "something" that could be a seed pod, or a disease. My husband, who was the plant guru, died in December and I do not know if that large green thing (almost shaped like a citron) is fruit, fungus or who knows? After I began watering it regularly, it produced tiny white flowers. How do I care for it? It lives indoors during the winter and outdoors when it is warm enough. What is warm enough?
The 'something' you describe is a citron fruit.
Continue to water it on a regular schedule. Since the citron is a citrus fruit, you would care for it the same as a citrus tree.
Here is a link that will help with your plant.