Figure 4.

Parietal pleural biopsy. a) Infiltration by adenocarcinoma with micropapillary pattern (single arrow). Multiple psammoma bodies are observed (double arrow). (Hematoxylin-eosin, ×100). b) Infiltration by adenocarcinoma with micropapillary pattern. (Hematoxylin-eosin, ×400). c) Immunohistochemical nuclear TTF-1 positivity of malignant cells. (×400). d) Immunohistochemical cytoplasmic SP-A positivity of malignant cells. (×400).