Presentation
The patient had a pneumonia that did not improve after treatment.
Patient Data
Patchy consolidation in the left lower lobe with reduced demarcation of the diaphragm. The left lower lobe bronchus is not visible, possibly due to an obstruction.
Vividly enhancing soft tissue mass at the left hilum with partial obstructive atelectasis of the left lower lobe and possible post-obstruction pneumonia based on the symptoms.
The triangular enhancing soft tissue mass in the prevascular mediastinum is the thymus and can be considered normal at this young patient's age.
The tubular and slightly hypodense structures next to the pulmonary vessels inside of the atelectasis are mucus-filled and dilated bronchi.
Case Discussion
Typical and atypical pulmonary carcinoid tumours cannot be distinguished with imaging alone and a histological workup is necessary. Surgery usually suffices as treatment for the former, whereas further treatment, such as chemotherapy, may be necessary for the latter.
Surgery was conducted and histology confirmed the diagnosis:
"Typical carcinoid of the lung (left lower lobe). The hilar resection margins are free of tumour. One hilar lymph node without neoplastic infiltration (0/1).
Additional findings: chronic recurring bronchitis with bronchiectasis."
Other lymph node regions were without neoplastic infiltration as well.
In cases of a prolonged pneumonia or an atelectasis that does not resolve, an underlying mass should always be suspected and evaluated with a chest CT scan.
A plausible differential diagnosis for a young patient with such symptoms would be a pulmonary sequestration.