Peroral pancreatoscopy in the diagnosis of mucin-producing tumors of the pancreas

Background: Mucin-producing tumor of the pancreas is an increasingly recognized clinical entity. However, the differentiation of benign from malignant mucin-producing tumors of the pancreas is challenging. Peroral pancreatoscopy as recently developed may have potential for the diagnosis of mucin-producing tumors of the pancreas. Methods: The subjects were 41 patients with clinically diagnosed mucin-producing tumors of the pancreas, 40 of whom underwent surgical resection. Autopsy findings were available in another patient with unresectable disease. Histologically, hyperplasia was identified in 3 patients, mildly atypical adenoma in 11, severely atypical adenoma in 16, and adenocarcinoma in 11. Peroral pancreatoscopy was performed before surgery or pathologic examination. The findings were retrospectively evaluated and compared with the histopathologic diagnosis. Results: Pancreatoscopic observation was successful in 30 patients (73.2%). Elevated lesions were identified in 22 (73.3%). Villous or vegetative elevations and red color markings were frequently found in severely atypical adenoma or adenocarcinoma. Tumor location (main or branch duct type) did not correlate with survival after resection. Partial resection was performed in 7 of 30 patients with nonmalignant tumors and resulted in favorable outcomes. Conclusion: Peroral pancreatoscopy can be used to differentiate benign mucin-producing tumors of the pancreas (hyperplasia and mildly atypical adenoma) from the more dysplastic lesions (severely atypical adenoma and adenocarcinoma) and may provide useful information for determining the type of surgery to be performed.