Correct!
2. Carcinoid tumor
Among the choices listed, carcinoid tumor is the most likely diagnosis. The close association of the mass with the superior segmental right lower lobe bronchus (Figure 3, arrow) suggests a lesion originating from the airway, and the patchy areas of ground-glass opacity that surround the mass (Figure 3, arrowheads) raises the possibility of hemorrhage associated with the lesion, which could reflect the vascular nature of a carcinoid tumor.
Figure 3. Axial contrast-enhanced thoracic CT shows a circumscribed superior segmental right lower lobe mass closely associated with the superior segmental right lower lobe bronchus (arrow). Patchy areas of ground-glass opacity (arrowheads) are present along the margins of the lesion, suggesting peri-lesional hemorrhage. The lesion shows no calcification and is relatively homogeneous-appearing on the soft tissue window image.
Furthermore, the patient’s relatively young age is appropriate for carcinoid tumor, but is atypically young for bronchogenic carcinoma. Inflammatory myofibroblastic tumor is a possibility, but the imaging features of this disorder are relatively non-specific and this lesion is considerably rarer than carcinoid tumor. Furthermore, inflammatory myofibroblastic tumor is frequently associated with calcification, which is not seen within this lesion. Chronic necrotizing aspergillosis typically occurs in middle-aged to older patients with relatively mild degrees of immunosuppression, such as chronic steroid use, alcoholism, chronic liver disease, diabetes mellitus, etc., or underlying structural lung disease, such as obstructive pulmonary disease, previous infection, prior radiation therapy, chronic inflammatory conditions (e.g., sarcoidosis), and occupational lung diseases; such history is not present in this case. Additionally, chronic necrotizing aspergillosis often appears as a slowly growing nodular opacity that subsequently cavitates by the time it reaches a substantial size, but cavitation is not seen in this lesion. Solitary fibrous tumors may arise in a variety of organ systems, but are most commonly encountered arising from the pleura, and therefore appear as an extraparenchymal mass, unlike the lesion in this case.).
Which of the following represents the next most appropriate step for the evaluation of this patient? (Click on the correct answer to proceed to the fifth of 6 panels)