Takahito Ohta

Superficial-type adenomas and adenocarcinomas of the colon and rectum: A comparative morphological study

BACKGROUND/AIMS It has been uncertain whether colorectal carcinomas preferentially arise on preexisting adenomas or de novo. However, from a morphological viewpoint, it seems unlikely that pedunculated or exophytic malignant polyps progress to the deeply ulcerated advanced carcinomas usually found clinically. METHODS The morphological features of 26 nonpolypoid, superficial-type colorectal tumors (17 adenomas and 9 adenocarcinomas) were compared to clarify the developmental route of colorectal carcinomas. RESULTS The adenomas and adenocarcinomas were very similar in size and gross appearance; however, examination of the surface appearances of unsectioned tumors by dissecting microscopy was helpful for distinguishing the two. Histologically, no adenomatous tissue was found in any case of superficial-type adenocarcinoma. Five of the nine adenocarcinomas, even including those of small size, invaded the submucosal layer, and two showed lymph node metastasis. CONCLUSIONS These findings suggest that superficial-type adenocarcinomas show rapid growth and aggressive behavior. We suggest that this type of carcinoma may not progress by the adenoma-to-carcinoma pathway but that it may arise from a very small superficial-type adenoma.

Non-Hodgkin's lymphoma in a patient with probable hereditary nonpolyposis colon cancer: report of a case and review of the literature.

AbstractPURPOSE: Hereditary nonpolyposis colorectal cancer kindreds are frequently associated with cancers in various organs, including endometrium, stomach, and ovary. However, hematologic malignancy has rarely been reported in association with this cancer syndrome. We present here the case of a probable hereditary nonpolyposis colon cancer patient in whom non-Hodgkin’s lymphoma developed after curative resection of colon cancer. Our experience with this rare case encouraged us to review the literature for reports indicating a possible relationship between these diseases. RESULTS: A 52-year-old male whose family history was consistent with the criteria for hereditary nonpolyposis colon cancer underwent right hemicolectomy for ascending colon cancer. Histologically the tumor consisted of adenocarcinoma that was moderately differentiated with mucinous foci and that invaded beyond the muscularis propria. Neither metastasis nor lymphoma was found in paracolonic lymph nodes. Eight months after surgery, the patient developed non-Hodgkin’s lymphoma of T-cell origin involving the ileum and lungs. Both colon cancer and lymphoma frequently showed microsatellite DNA instability, sharing alteration in a locus of chromosome 7 (D7S501). CONCLUSION: A possible association of hematologic malignancy with hereditary nonpolyposis colon cancer reported in the literature, together with a report that MSH2-deficient mice are susceptible to malignant lymphoma, strongly supports the finding that this patient’s lymphoma was related to hereditary nonpolyposis colon cancer. Overall, this case manifested a distinct clinical course similar to that observed in an animal model that is deficient in DNA mismatch repair machinery, thus providing scientific and clinical implications for understanding the molecular basis of these tumors and for critical management of hereditary nonpolyposis colorectal cancer patients, respectively.

Angiogenesis in poorly differentiated medullary carcinoma of the stomach

We studied the role of angiogenesis in patients with medullary type poorly differentiated adenocarcinoma (MTPDA) of the stomach. Immunohistochemical analyses were conducted using antibodies against factor VIII (endothelial cells), vascular endothelial growth factor (VEGF) and its receptors (KDR andflt-1), and basic fibroblast growth factor (bFGF) and its receptors (bek andflg). Archival specimens of MTPDA (n=22) and non-MTPDA (n=47) were studied. The expression of VEGF and bFGF, the vessel count, and positivity ofKDR on endothelium were all significantly higher in MTPDA than in non-MTPDA. The vessel count correlated with the VEGF expression in MTPDA. The vessel count and VEGF expression increased with the increasing stage of disease in MTPDA but not in non-MTPDA. The expression of bFGF and its receptors did not correlate with the vessel count and stage of disease in either type. These findings thus suggest that the biological behavior of medullary type poorly differentiated adenocarcinoma of the stomach is angiogenesisdependent. The correlation of the VEGF expression and its endothelial receptors with the vessel count and the stage of disease thus suggests that VEGF is a factor responsible for the induction of angiogenesis in this type.

Heterotopic pancreas with calcification: A lesion mimicking leiomyosarcoma of the stomach☆

Current affiliations: The Department of Internal Medicine and Department of Surgery, National Ishikawa Hospital, Kanazawa, and the Department of Medical Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan. Reprint requests: Rie Oka, MD, The Department of Internal Medicine, National Ishikawa Hospital, 150 Tezuka-machi, Kaga, 922-0405, Japan. Copyright

The effect of UFTM therapy on primary and metastatic colon cancer from the same human xenotransplanted into nude mice

Successful simultaneous transplants of a cancer of the ascending colon from a 60 year old woman, taken from 3 sites: the primary focus, a lymph node metastasis, and a hepatic metastasis, into nude mice yielded KHC (-P,-N,-H) strains. These three strains were compared under uniform conditions of nude mouse transplantation from the standpoints of morphological variation, growth rate, and sensitivity to chemotherapy. The results showed no major differences in morphology or growth rate. However, an effect on chemotherapeutic sensitivity was observed in KHC-P and KHC-N, with reduction rates of 25.8 per cent and 31.4 per cent, respectively, in the MMC only treatment group with large doses, and in KHC-N and KHC-H, with reduction rates of 46.5 per cent and 34.9 per cent, respectively, in the UFTM group. Chemotherapy sensitivity not only exhibited heterogeneity by site, but also differed according to the chemotherapeutic agent used. These results indicate that this method of nude mouse transplantation is a good experimental system for comparing primary foci and metastases under uniform conditions, and also strongly suggest the presence of heterogeneity in sensitivity to chemotherapy.

Minute Rectal Cancer Associated with Nodular Involvement —A Case Study—

Abstract: This study presents the case of a patient with minute type Ha rectal cancer with a diameter at its largest of only 5 mm, with infiltration as far as the submucosal layer (sm) and positive parietal lymph node metastasis.

Diagnosis for the depth of gastric cancer by endoscopic ultrasonography.

ラジアルスキャン超音波内視鏡を使用し, 胃癌36例を対象に超音波断層像による癌深達度の判定について検討した.正常胃壁は高エコー層, 低エコー層が交互に現れる5層構造として明瞭に認識出来た.癌巣は一般に低エコーレベルを呈し, 正常5層構造の中断・破壊・不整が深達度判定の指標となった.1群の壁在リンパ節では5mm以上に腫大したものは描出可能であった.正確な深達度診断には癌巣が超音波振動子と垂直方向に位置することが必要で, 幽門狭窄症例などこの条件を満たさない症例では描出不能であった.