A 45-year-old male presents with a fever, cough, and difficulty breathing. He recently received chemotherapy for lymphoma. Physical examination reveals bilateral crackles. What could be the diagnosis and the next steps?
Given the history of recent chemotherapy, the patient is likely to be immunocompromised and therefore at risk of opportunistic infections, including fungal pneumonia. Causes can include Pneumocystis jirovecii, as well as other fungi like Aspergillus. The next steps would include a chest X-ray or CT scan, as well as a complete blood count, blood cultures, and potentially bronchoalveolar lavage if the initial workup is not diagnostic. Treatment would depend on the identified organism but could include antifungal agents.