Figure 1.

Initial cytology findings of transbronchial needle aspiration, cell block, and immunohistochemical staining of the right station 4 lymph node. A, Hypercellular smears are showing 3-dimensional clusters of malignant cells with prominent nucleoli and increased nuclear to cytoplasmic ratios (ThinPrep, ×20). B and C, Cell block preparation demonstrating poorly differentiated malignant cells arranged in sheets (hematoxylin-eosin stain, ×20 and ×40). The tumor cells are immunoreactive for cytokeratin 7 (D), MOC-31 (F), and androgen receptor (I) and focally for prostate-specific antigen (G; red arrow) and are negative for cytokertin 20 (E) and prostatic acid phosphatase (H) (immunohistochemical staining, ×20).