An Unusual Cause of Productive Cough with Yellow Sputum

We declare that this manuscript is original, has not been published before and is not currently being considered for publication elsewhere. There are no conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. We obtained informed consent from the patient. The manuscript has been read and approved by all named authors. S. Kitagawa diagnosed the case and wrote the manuscript, and is the article guarantor.