1. Jass JR, Sobin LH . Histological Typing of Intestinal Tumours. Berlin, Germany; Springer-Verlag, 1989.
2. Japanese Society for Cancer of the Colon and Rectum. Japanese Classification of Colorectal Carcinoma, First English Edition. Kanehara: Tokyo, Japan, 1997.
3. Hamilton SR, Vogelstein B, Kudo S, et al. WHO histological classification of tumours of the colon and rectum. In: Hamilton SR, Aaltonen LA (eds). World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Digestive System. IARC Press: Lyon, France, 2000, pp 103–143.
4. Ruschoff J, Dietmaier W, Luttges J, et al. Poorly differentiated colonic adenocarcinoma, medullary type: clinical, phenotypic, and molecular characteristics. Am J Pathol 1997;150:1815–1825.
5. Sugao Y, Yao T, Kubo C, et al. Improved prognosis of solid-type poorly differentiated colorectal adenocarcinoma: a clinicopathological and immunohistochemical study. Histopathology 1997;31:123–133.