Clonality Assay of Dysplastic Epithelial Lesions of the Stomach

PURPOSE: Dysplasia or flat adenoma of the stomach is regarded as a precancerous lesion. However, the frequency and the evolutionary process of malignant transformation of gastric dysplasia are still debated. In order to see whether the lesion was a monoclonal or a polyclonal proliferation, clonality was assayed by X-linked HUMARA polymorphism. MATENRIALS AND METHODS: DNA was extracted from the paraffin-embedded tissue of 16 consecutive cases of endoscopic biopsy, eight of which supplied both dysplastic and nondysplastic tissue for comparison. HUMARA was amplified by PCR with or without pretreatment with methylation- sensitive restriction enzyme, HpaII. The amplification products were electrophoresed on polyacrylamide gel and silver-stained. RESULTS: Among the 16 cases, 13 cases were informative and 3 cases noninformative. Of the 13 cases, one case showed skewed lyonization, rendering 12 cases to be analyzed further. A monoclonal band pattern was noted in 2 cases, and a polyclonal band pattern in 10 cases. A review of the histopathologies of the monoclonal and the polyclonal cases did not reveal features discriminating the two groups. CONCLUSION: These results suggest that gastric dysplasia is a disease entity heterogeneous in the genetic level, and many cases may be non-neoplastic.

A Case of Rectal Carcinoid Tumor / 대한소화기내시경학회지

Carcinoid is a tumor that primarily affects the intestinal tract, which arises from entero-chromaffin cells. Rectal carcinoid tumor is a relatively rare neoplasm originated in Kul-chitszky cell and clinicians have the difficulties in predicting their malignant potential and in proper treatment. These cells are found to increase in the distal small intestine, are common in the appendix, and then decrease within the mucosa of the colon from cecum to rectum. In the cumulative world literature, the incidence of carcinoids of rectum is slightly higher than 10 percent. All of these tumors are within reach of the rigid procto-sigmoidoscope, most being located between 4 and 13 cm from the anal verge. Eighty five percent are found on the anterior and lateral walls. The tumors are usually submucosal and light yellowish or reddish color. The vast majority of rectal carcinoid tumors are be-nign, which can be treated by local excision safely. Lesions larger than 2 cm and invading the muscular wall of the rectum should be considered malignant, which are treated by more radical surgery such as abdominoperitoneal resection. We experienced a case of rectal carcinoid tumor, which was excised by endoscopic polypectomy, so we present this case with a review of relevant literatures.

The Study of Proliferating Cell Nuclear Antigen in Colorectal Carcinoma

The determination of proliferative activity in the colorectal mucosa has been used for different purposes as the estimation of cancer risk and the assessment of disease activity in ulcerative colitis. But the prognostic significance of proliferative activity in colorectal carcinomas remains controversial. To investigate the prognostic significance of proliferative activity in colorectal carcinomas, the author estimated the proliferative activity immunohisto chemically using the monoclonal antibody PCNA and compared with clinicopathological data in 62 colorectal carcinomas. The results were as follows: 1) The reactivity of PCNA was more pronounced at the infiltrative margins of the tumors and tumor cells within the vascular or lymphatic channels. 2) The mean PCNA index of colorectal carcinomas was 40.5?0.4%. PCNA indices had positive correlations with lymph node invasion(p<0.05), liver, metastasis(p<0.05), Dukes' stage(p<0.01) and TNM classification(p<0.01), and didn't correlated with location of tumor, size of tumor, histological type and lymphtic or vascular invasion. 3) The patients with high PCNA index(more than 45%) represented higher recurrence or metastasis rate(37.5%) than those with low PCNA index (less than 45%)(19.3%) in Dukes B or C colorectal carcinomas during the follow-up periods, but not significant statistically. These results suggested that the reactivity of PCNA may be a useful prognostic factors in colorectal carcinomas.