A 57-year-old man returning from Bangladesh developed a severe lung infection that lasted several weeks and required hospitalization with breathing support. Doctors initially thought he had tuberculosis or bacterial pneumonia, but standard tests came back negative. Advanced fungal testing eventually identified the cause as histoplasmosis, a fungal infection he likely caught while supervising construction work. After treatment with antifungal medications, the patient recovered and was discharged to continue medication at home for a year.