Galectin-3 and PTEN expression in pancreatic ductal adenocarcinoma, pancreatic neuroendocrine neoplasms and gastrointestinal tumors on fine-needle aspiration cytology.

OBJECTIVE: Galectin-3 has been implicated in the carcinogenesis of pancreatic ductal adenocarcinoma (PDAC). Its applicability in pancreatic fine-needle aspiration (FNA) in separating malignant from benign lesions has never been addressed. In addition, a correlation between Galectin-3 and tumor suppressor phosphatase and tensin homolog (PTEN) and their potential diagnostic value has never been tested.

STUDY DESIGN: This study analyzed Galectin-3 immunohistochemical expression in FNA cell blocks of PDAC, pancreatic neuroendocrine neoplasms (PNEN), gastrointestinal stromal tumors (GIST) and non-tumor pancreatic tissue. In parallel, Galectin-3 and PTEN levels were evaluated in a tumor tissue microarray (TMA).

RESULTS: Forty-four of 46 PDAC FNA and 32 of 33 PDAC TMA demonstrated tumor-specific Galectin-3 positivity. In contrast, Galectin-3 was not detected in PNEN and GIST. Total loss of PTEN was displayed by 26 of 33 PDAC, while non-neoplastic tissues all retained PTEN expression.

CONCLUSION: Galectin-3 could be a valuable marker to help diagnose PDAC and rule out PNEN and GIST. In addition, PTEN positivity strongly argues against a diagnosis of PDAC. These data also advocate their potential diagnostic roles in the work up of challenging cytologic cases requiring ancillary test confirmation.