Figure 1

Typical H&E and immunohistochemical findings in micropapillary pattern-positive cases. (a) H&E staining. (b) Expression of CD68 was observed in macrophages (arrow head) but not in carcinoma cells with a micropapillary pattern (arrow). (c) Expression of MUC1 was observed in carcinoma cells with a micropapillary pattern (arrow) but not in macrophages (arrow head). (d) A micropapillary pattern in the space entrapped by atypical cells (inside pattern). (e) A micropapillary pattern in the normal alveolar space (outside pattern).