Correct!
2. Perform percutaneous transthoracic lung biopsy
3. Perform robotic assisted bronchoscopy
5. More than one of the above
Given the lack of a definitive diagnosis and the broad differential diagnostic considerations for an enlarging, indeterminate pulmonary nodule in an immunosuppressed patient, tissue sampling is appropriate. There are a number of options for tissue sampling for this lesion, including percutaneous transthoracic needle biopsy, bronchoscopic techniques, and even surgical lung biopsy, possibly using a video-assisted approach. A surgical biopsy may be needlessly invasive at this point, given that other less invasive measures may obtain the diagnosis and are commonly attempted first when feasible. The lesion is amenable to percutaneous transthoracic needle biopsy, although the access route may be limited- an anterior approach may be favored given the long intrapulmonary needle course mandated by a posterior approach, but the anterior approach window is limited by the osseous structures of the chest wall. Robotic-assisted bronchoscopy is an alternative method that may be able to access the nodule.
The patient underwent robotic assisted bronchoscopic biopsy and bronchioloalveolar lavage of the left apical nodule (Figure 5).
Figure 5: Robotic-assisted navigational bronchoscopy. Fluoroscopic image shows the robotically-guided needle within the nodule (arrows). The image at the lower left shows direct bronchoscopic visualization of the nodule, and the lower right image shows the robotic guiding system.
The results of this procedure revealed Escherichia coli, identical to the organism discovered in the patient’s urinary culture, sensitive to Augmentin. Histopathological analysis showed sheets of oval- to spindle-shaped histiocytes with the presence of Michaelis-Gutmann bodies (Figure 6).
Figure 6: Robotic-assisted bronchoscopic biopsy specimen from the left upper lobe nodule. (A) Transbronchial biopsy specimen (hematoxylin & eosin, 400X) shows sheets of oval- to spindle-shaped histiocytes, some of which had light purple cytoplasmic inclusions (arrow). (B) Von Kossa staining highlights the inclusions to be positive for calcium (arrow), indicating the presence of Michaelis-Gutmann bodies.
Based on this information, which of the following represents the most likely diagnosis for this patient? (Click on the correct answer to be directed to the ninth and final page)