Hi. I’m an adult who was treated last year at Mayo for an unidentified fungal infection/disseminated histoplasmosis. I was successfully treated with the antifungal Itraconazole. I never had any masses or pressure. My illness was discovered incidentally. My understanding is that possible sources of this type of infection include bats, chickens, and/or breathing in fungal spores from soil containing bird droppings. I wish your son the best of luck in recovering from his illness.