Clinicopathological Study of Poorly Differentiated and Undifferentiated Carcinoma of the Large lntestine -Classification and Special Reference to the Endocrine Cell Carcinoma-

Masahiko Otsuka, Yo Kato*

First Department of Surgery, The Jikei University School of Medicine
*Department of Pathology, Cancer Institute

The characteristics of poorly-differentiated and undifferentiated carcinoma of the large intestine were investigated on the basis of 64 resected cases at the Cancer Institute Hospital, Tokyo, during the period 1946-1988, corresponding to 2.4% of all carcinoma of the large intestine resected during the same period. Although mean age and male to female ratio did not differ much from the corresponding parameters in well-or moderatelydifferentiated adenocarcinoma, the proportion of tumors located in the right side of the colon was higher than in the latter. The tumors were classified into medullary (med), intermediate (int) or scirrhous (sci) type depending on the amount of fibrous stroma in the tumor tissue. Med tumors were accompanied by significantly less lymphatic invasion, less lymph node metastasis and less peritoneal dissemination than non-med (int+sci) tumors. There was also a significant difference in survival rates between patients with med and non-med tumors. Endocrine cell carcinoma was detected in 6 cases (9.4%) by means of the Grimelius reaction, immunohistochemical staining for NSE and electron microscopy. These tumors were of the med type and five of them were associated with a poor outcome (death within one year after surgery). Based on these data, it seems reasonable and clinically useful to classify poorly-differentiated and undifferentiated carcinoma of the large intestine into three subtypes: (1) endocrine cell carcinoma (poor prognosis) (2) medullary carcinoma exclusive of endocrine cell carcinoma (relatively good prognosis) and (3) non-medullary carcinoma (poor porgnosis).

Key words
poorly differentiated adenocarcinoma of the colon and rectum, undifferentiated carcinoma of the colon and rectum, endocrine cell carcinoma of the colon and rectum

Reprint requests
Masahiko Otsuka First Department of Surgery, The Jikei University Scool of Medicine
3-25-8 Nishi-shinbashi, Minato-ku, Tokyo, 105 JAPAN

Accepted
January 8, 1992

To read the PDF file you will need Abobe Reader installed on your computer.