Hi and welcome to HCM.
Unfortunately yes,it can be. It is usually diagnosed by detecting such shadows on xray. But also pneumonia
or localized emphysema
,bronchiectasie and other smoking
related disease can be. CT, bronchoscpy and biopsy
can give exact diagnosis. YOu must be ready for everything but hope for the best. Also if it is cancer it is necessary to see is it operabile and which way of treatment is the best for him. Wish you good health.