Fig. 5

Microscopic findings. a The tumor was pathologically diagnosed as an anaplastic carcinoma of the pancreas, containing pleomorphic tumor cells (b), spindle tumor cells (c), and moderately differentiated ductal carcinoma (d) (H& E × 40). b-d Positive staining of granulocyte-colony stimulating factor (G-CSF) immunohistochemistry in the cytoplasm of formalin-fixed paraffin-embedded specimen (×400). b Pleomorphic tumor cell variant, composed of bizarre, multinucleated giant cells that contain abundant eosinophilic cytoplasm. The nuclei were large, hyperchromatic, and contained variable numbers and sizes of nuclei. Numerous mitoses were easily identified, including bizarre mitoses. These cells were suspended in a sea of neutrophils. c Spindle-cell component resembling a sarcoma, with cells arranged in fascicles, sometimes in a herringbone pattern. There was less pleomorphism than in pleomorphic tumor cells, whereas significant atypia was common. d Moderately differentiated ductal carcinoma