Test results confirm or exclude what the doctor has already suspected to be a diagnosis according to symptoms.
Since there is a fact that your husband has a shadow on his lungs, there was already test result with picture of his lungs.
Probably, he was performed a chest x-ray (the doctor saw the shadow and according to location and its features suspected to be infection), but, to be on a safe side he probably ordered a lung CT scan, which is a golden standard for diagnosing lung diseases, especially the lung cancer.
So, I guess the doctor is waiting for the lung Ct scan results.