Solid and cystic papillary neoplasms of the pancreas: Report of four cases - ZEYTUNLU, Murat; FIRAT, Özgür; NART, Deniz; ÇOKER, Ahmet; YÜZER, Yıldıray; TEKEŞİN, Oktay and ÖZÜTEMİZ, Ömer and KİLLİ, Refik (Turkish Journal of Gastroenterology, 2004)