Correct!
2. Bronchoscopy with endobronchial ultrasound (EBUS)
At this juncture, the patient’s lack of clinical improvement, his progression on CT scan and the development of enlarged mediastinal lymph nodes suggest tissue biopsy is warranted. Of the choices listed, bronchoscopy with biopsy of the mediastinal lymph nodes is least invasive and probably the best choice although none are necessarily wrong. It is unclear if knowing there is increased glucose uptake in the mediastinal lymph nodes18F-FDG PET-CT scan would be helpful, VATS is invasive, and needle biopsy would only sample the lymph nodes.
Bronchoscopy with bronchoalveolar lavage and EBUS were performed. BAL fluid recovered from both lower lobes also was positive for metastatic prostate cancer indicating lymphangitic spread into the lungs. Lymph nodes at station 4R, 7 and 10R were positive for metastatic prostate cancer.
Lymphangitic carcinomatosis is defined as presence of tumor present in the lymphatic vessels of bronchovascular bundles, interlobular septa and pleura (1). It is most commonly seen with breast, lung, colon and stomach cancer but has been rarely reported with prostate cancer (2). Chest radiograph is not very sensitive and 25% of patients with biopsy-proven lymphangitic carcinomatosis may have normal chest radiographs (1). Findings are usually of a reticulonodular pattern with thickening of interlobular septa which may resemble Kerley B lines. On CT scan the typical appearance is interlobular septal thickening which may either be smooth or nodular. Hilar and mediastinal lymph node enlargement is seen in 40 to 50%. Bronchoalveolar lavage has been reported to have a high diagnostic yield in lymphangitic carcinomatosis (3).
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