Correct!
4. 1 or 3
Given the lack of a tissue diagnosis from the previously performed bronchoscopic biopsy, a procedure capable of obtaining a larger tissue sample is now indicated. Therefore, repeat bronchoscopy with endoscopic ultrasound and transbronchial biopsy is not the best choice among those listed. Both percutaneous transthoracic fine needle aspiration and core biopsy and surgical biopsy procedures provide larger tissue samples than bronchoscopic biopsies [albeit at a higher rate of associated complications]. The surgical approach to a tissue diagnosis- either mediastinoscopy or video-assisted thoracoscopic biopsy- could target the right paratracheal lymph nodes or pleural space abnormalities in this patient. Percutaneous transthoracic fine needle aspiration and core biopsy could target the low attenuation areas in the medial right middle lobe and / or lower lobe (Figure 8).
Further clinical course: The patient underwent percutaneous transthoracic fine needle aspiration and core biopsy, but the tissue obtained at this procedure did not yield a diagnosis. The patient subsequently underwent a thoracoscopic surgical biopsy procedure, but that procedure was complicated by adhesions, and thus the procedure was converted to a mini-thoracotomy. The right pleural abnormality was sampled, as were portions of the right paramediastinal mass. The surgical lung biopsy material showed Fibroinflammatory process involving lung and mediastinum characterized by fibrous and myofibroblastic proliferation, sclerotic nodules, streaming fibrosis, polyclonal plasma cells, mixed T and B lymphocytic infiltration and increased vascularity and entrapped lung, but with no features of malignancy. The inflammatory infiltrate consisted of lymphocytes and plasma cells with scattered eosinophils, and in some areas, the fibrosis appeared quite dense and suggestive of a keloidal type deposition. Immunohistochemistry studies showed only rare scattered B-cells with normal co-expression of PAX5, and majority of the lymphocytes were small T-cells. No Reed-Sternberg cells were identified with the aid of CD30, CD15 stains. EMA and PC3 stains highlighted the largely decoyed pulmonary parenchyma in the background. Calretinin and CK5 stains were negative. In situ hybridization for kappa and lambda light chain highlighted a polytypic plasma cell population with only a small number of IgG positive plasma cells demonstrating low co-expression of IgG4. Gram staining was negative.
Given these characteristics, which of the following represents the most likely diagnosis for this patient? (Click on the correct answer to proceed to the last panel)