Correct!
5. Cotton fibers
Aspergillus infection, owing to the organism’s ability to fix calcium, may appear hyperattenuating at thoracic CT, and cavitation may be present simultaneously with this infection. However, Aspergillus infections often occur in typical clinical contexts that are lacking in this case, and usually thoracic infection with Aspergillus species typically shows an imaging appearance significantly different than the appearance of the lesion in this patient.
Staphylococcus aureus pneumonia often appears as an area of lobar consolidation, although a bronchopneumonia pattern may be encountered as well. Cavitation within the area of pneumonia may occur with certain pneumococcus serotypes, and cavitary lung nodules may be seen with this infection when the source of the infection is intravascular, as with endocarditis or infection of indwelling central venous catheters. However, the hyper- and hypoattenuating appearance of the lesion would be distinctly unusual for Staphylococcus aureus infection.
Spindle cells may be seen on percutaneous transthoracic needle biopsies of patients with sarcomas, vascular, or fibrous tumors. Solitary fibrous tumor of the pleura would be one consideration for a mass in contact with the chest wall when percutaneous transthoracic biopsy results show spindle cells. However, solitary fibrous tumor of the pleura, as well as sarcomas and thoracic vascular tumors, would not present with the unusual appearance of the lesion in this case.
Paraffin wax could be obtained on a transthoracic percutaneous needle biopsy if the patient had previously undergone thoracoplasty for tuberculosis infection, but wax shows fatty attenuation on thoracic CT, and thoracoplasty using paraffin wax has not been performed for a number of years, and therefore it is unlikely to encounter this procedure in a patient of only 40 years age.
The most likely diagnosis for the lesion in this patient is which of the following?