Figure 2.

Lack of expression of M2-pyruvate kinase in duct-derived cancers: (a) Immunohistochemical staining for M2-pyruvate kinase on diffuse anaplastic pancreatic ductal adenocarcinoma (× 20), demonstrating a complete lack of staining in tumour epithelium; (b) Immunohistochemical staining for M2-pyruvate kinase on poorly differentiated pancreatic ductal adenocarcinoma, with adjacent chronic pancreatitis (× 20), demonstrating a complete lack of staining in the tumour, but intense staining in the benign non-ductal reactive epithelium; (c) Immunohistochemical staining for M2-pyruvate kinase on well differentiated adenocarcinoma pancreas (× 20); (d) Immunohistochemical staining for M2-pyruvate kinase on metastatic pancreatic ductal adenocarcinoma in the regional lymph node (× 20), demonstrating a complete lack of staining in the tumour epithelium and lymph node.