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Biomedical subjects

Yo Kato

Publications and source records attributed to Yo Kato.

30 records · Page 2Linked to original sources
PubMed2003

Surgical treatment of intraductal papillary-mucinous tumor (IPMT) of the pancreas: operative indications based on surgico-pathologic study focusing on invasive carcinoma derived from IPMT.

BACKGROUND/PURPOSE: Between 1979 and 2000, 51 patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas underwent surgical resection. METHODS: The patients were reviewed to disclose the surgical pathology of invasive carcinoma derived from IPMT and to determine the surgical indications for IPMT on the basis of the pathologic findings. RESULTS: The incidence of invasive carcinoma derived from IPMT according to the localization of the tumor was as follows: 4/9 (44%) in the main pancreatic duct (MPD type), 4/9 (44%) showing ductal spread from the MPD to branch ducts (mixed type), and 2/33 (6%) in the 2 branch duct (branch type). The maximal size of the intraductal spread of invasive carcinomas (8 of 18 cases in the MPD and mixed type together and 2 of 33 cases in the branch type) was as follows: 6/8 (75%) in the MPD and mixed type were over 6 cm in size, and the 2-branch-type invasive carcinomas were within the 3-cm size range. CONCLUSIONS: We concluded that for both invasive and noninvasive IPMTs, surgical resection was necessary for any MPD or mixed-type IPMTs, and that surgical resection was appropriate for branch-type lesions larger than or equal to 3 cm in diameter, or for lesions smaller than 3 cm showing rapid growth on clinical images.

Aged↗
PubMed2003

Minute gastric carcinoid tumor with regional lymph node metastasis.

We report a patient with a minute gastric carcinoid tumor with lymph node metastasis, and a small gastric cancer. A 50-year-old man having a diagnosis of an elevated lesion on the anterior wall of the gastric body, detected by a series of upper gastrointestinal examinations, was referred to the Cancer Institute Hospital. Careful upper fluoroscopy disclosed a small superficial depressed lesion with converging folds and a superficial elevated lesion covered with nonspecific gastric mucosa. With a final preoperative diagnosis of depressed early cancer and minute carcinoid tumor of the stomach, made by upper gastrointestinal examinations including biopsy, the patient underwent segmental gastrectomy and perigastric lymph node dissection. Histological examination of the resected specimen revealed a lymph node metastasis from a gastric carcinoid tumor of 5-mm diameter, in addition to an early gastric cancer of poorly differentiated adenocarcinoma. Small gastric carcinoid tumors have been regarded as being benign neoplasms biologically. However, the case we present suggests that attention should be paid to the possibility of metastasis at the time of treatment for a minute sporadic gastric carcinoid tumor. We therefore discuss the malignant potential of these tumors, mainly from the viewpoint of histopathological classification, to gain understanding so that the patients can be treated adequately.

Adenocarcinoma↗
PubMed2003

Colliding gastric and intestinal phenotype well-differentiated adenocarcinoma of the stomach developing in an area of MALT-type lymphoma.

A 73-year-old man presented with an abnormal gastric shadow during a check-up of atomic bomb survivors. Radiological examination and endoscopy of the upper gastrointestinal tract revealed a protruding tumor, type 0-I+IIa, on the lesser curvature of the midstomach. An initial diagnosis of early gastric cancer was made and a segmental gastrectomy was planned. However, distal gastrectomy with D3 lymph node dissection was necessary, because intraoperative frozen section showed that the paraaortic lymph nodes (N3) were positive for cancer. The tumor in the resected specimen was, microscopically, a well-differentiated tubular adenocarcinoma (tub1) with pT2 (MP), pN3, ly2, and v1, in final (f) stage IV. The tumor cells of the type 0-I segment appeared as gastric phenotype and those of the type 0-IIa segment as intestinal phenotype. The border between the two was distinct. The tumor had focally invaded the muscularis propria where only the gastric phenotype was shown and the histological type became less differentiated. Thus, special attention should be paid to possible unexpected deep-wall invasion and lymph node metastasis in well-differentiated adenocarcinomas of the gastric phenotype. Further, in this patient, diffusely proliferating low-grade lymphoma was also observed incidentally in the gastric mucosa within and around the carcinoma. This was diagnosed as mucosa-associated lymphoid tissue (MALT)-type lymphoma with aberrant expression of BCL10. Finally, this case was considered to be a colliding gastric and intestinal phenotype well-differentiated adenocarcinoma of the stomach developed in an area involved by MALT-type lymphoma. Because no Helicobacter pylori was detected throughout the mucosae and the patient had no history of its infection, the three tumors may have developed under the same conditions as those seen in Helicobacter pylori infection, but without this infection.

Adenocarcinoma↗
PubMed2002

Genetic and histological assessment of surgical margins in resected liver metastases from colorectal carcinoma: minimum surgical margins for successful resection.

HYPOTHESIS: There have been few reports on the minimum surgical margins (SMs) required for successful liver resection in patients with colorectal metastases. This minimum requirement may be narrower than the previously recommended margin of 10 mm. OBJECTIVES: To identify the minimum margins by assessing the presence of micrometastases around the tumor using genetic and histological techniques, and to investigate whether SMs are associated with patterns of tumor recurrence or patient survival. DESIGN: Prospective and retrospective studies. SETTING: Tertiary referral cancer center. PATIENTS AND METHODS: Fifty-eight patients who underwent 62 liver resections for hepatic metastasis from colorectal cancer between December 1, 1996, and November 30, 2000, were included in the study. Tissue samples taken from the tumor, surrounding liver parenchyma, and Glisson pedicle near the tumor were tested for K-ras and p53 mutations using the mutant allele-specific amplification method. For the retrospective study on patient outcomes, 194 patients who had undergone liver resections between 1980 and 2000 were analyzed according to their SMs. RESULTS: Of the 62 sets of samples from liver metastases, 39 were positive for K-ras and p53 gene mutations or both. Micrometastases in the liver parenchyma surrounding colorectal metastases were present in 2.0% (4/199) of tested samples and were located within 4 mm of the tumor border. Micrometastases via Glisson pedicle were more common (14.3% [3/21]), but these were also confined to a short distance from the tumor edge (</=5 mm). Of the 5 micrometastases detected by genetic analysis, only 2 were confirmed by histopathological examination. The analysis of patient outcomes demonstrated that the incidence of cut-end recurrence (relapse in the bed of resection) decreased from 20.0% to a range of 5.6% to 7.5% when the SM is 2 mm or more. The incidence of definite cut-end recurrence in patients with SMs less than 2 m, 2 to 4 mm, and 5 mm or wider was 13.3% (6/45), 2.8% (1/36), and 0% (0/102), respectively. The SM was not a significant prognostic factor in patient survival. CONCLUSIONS: Micrometastases around liver tumors are not common, and most are confined to the immediate vicinity of the tumor border. We propose an SM of 2 mm as a clinically acceptable minimum requirement, which carries approximately a 6% risk of margin-related recurrence. Because liver resection provides the only chance of cure, complete removal of the tumor with a minimum margin is justified when technically unavoidable because of the size, location, number of tumors, or successive resections.

Adult↗
PubMed2002

Familial adenomatous polyposis associated with multiple endocrine neoplasia type 1-related tumors and thyroid carcinoma: a case report with clinicopathologic and molecular analyses.

We describe a sporadic case with familial adenomatous polyposis, multiple endocrine neoplasia type 1 (MEN1)-related tumors (an endocrine cell tumor of the pancreas and bilateral parathyroid tumors), and a papillary thyroid carcinoma. To clarify how mutations of the adenomatous polyposis coli ( APC ) gene and the MEN1 gene, responsible for familial adenomatous polyposis and MEN1, respectively, might have contributed to tumorigenesis in this case, we studied germline mutations in both genes and loss of heterozygosity at their genetic loci in multiple lesions. In addition, we performed immunohistochemistry for beta-catenin, associated with the function of the APC gene. A germline mutation was found in the APC gene but not in the MEN1 gene. Normal allelic loss at the APC gene locus was observed in bilateral parathyroid tumors. Immunohistochemical staining of beta-catenin demonstrated accumulation in the cytoplasm in addition to membrane staining in all analyzed tumors and a strong nuclear reaction in the endocrine cell tumor of the pancreas. The presence of normal allelic deletions of the APC gene in bilateral parathyroid tumors and nuclear staining of beta-catenin in the pancreatic tumor in addition to the germline mutations suggests that functional loss of the APC gene played an important role not only in familial adenomatous polyposis but also in the MEN1-related tumors in this case.

Adenomatous Polyposis Coli↗
PubMed2000

Incidence of lymph node metastasis from early gastric cancer: estimation with a large number of cases at two large centers.

BACKGROUND: The presence of lymph node metastasis (LNM) is the most important prognostic factor for patients with early gastric cancer (EGC). A D2 gastrectomy has been the gold standard treatment. Strict criteria for endoscopic mucosal resection have been widely accepted in Japan. There are some trials aimed at expanding the indications for local treatment, although there has not been a comprehensive review of the risk of LNM with the lesions of EGC.METHODS: We investigated 5265 patients who had undergone gastrectomy with lymph node dissection for EGC at the National Cancer Center Hospital and the Cancer Institute Hospital. Nine clinicopathological factors were assessed for their possible association with LNM.RESULTS: None of the 1230 well differentiated intramucosal cancers of less than 30 mm diameter regardless of ulceration findings, were associated with metastases (95% confidence interval [CI], 0-0.3%). None of the 929 lesions without ulceration were associated with nodal metastases (95% CI, 0-0.4%) regardless of tumor size. Similarly to findings for intramucosal cancers, for submucosal lesions, there was a significant correlation between tumor size larger than 30 mm and lymphatic-vascular involvement with an increased risk of LNM. None of the 145 differentiated adenocarcinomas of less than 30-mm-diameter without lymphatic or venous permeation were associated with LNM, provided that the lesion had invaded less than 500 &mgr;m into the submucosa (95% CI, 0-2.5%).CONCLUSION: Based on our large series of cases, we have been able to clarify the risks associated with EGC and to propose expansion of the criteria for local treatment. However, accurate histological evaluation of the resected specimens is essential to avoid recurrence for such EGCs that should be cured.

Journal Article↗
PubMed1999

Cardia carcinomas of intestinal type are associated with histologic changes in the gastric mucosa.

BACKGROUND: Previous studies of Japanese patients showed that distal gastric carcinomas (of the corpus or the antrum) were associated with histologic changes in the non-neoplastic gastric mucosa. These changes (cells with ciliated metaplasia, with large and small mucus-negative vacuoles, intramucosal glandular cysts, and extensive intestinal metaplasia) were often found in carcinomas of intestinal type.METHODS: In the present work, similar mucosal changes were searched for in surgical specimens carrying a carcinoma of the cardia. A total of 12 079 archival histologic sections, corresponding to 563 gastrectomies performed in Japanese patients, were analyzed.RESULTS: Of the specimens with cardia carcinoma of intestinal type seen in Tokyo ( n = 169) and in Matsuyama ( n = 168), 53.3% and 63.1% contained intramucosal cysts; 39.6% and 51.8%, ciliated metaplastic cells; 34.9% and 30.4%, large vacuolated cells; and 7.7% and 11.9%, small vacuolated cells; and 69.8% and 68.5% had high intestinal metaplasia scores, respectively. These percentages were significantly higher than those for cardia carcinomas of diffuse type in Tokyo ( n = 153) and in Matsuyama ( n = 73), in which 30.7% and 34.2% of the specimens had intramucosal cysts; 17.6% and 17.8%, ciliated metaplastic cells; 14.4% and 9.6%, large vacuolated cells; and 3.9% and 4.1%, small vacuolated cells; and 43.1% and 39.7% had high intestinal metaplasia scores, respectively.CONCLUSION: Thus, similarly to carcinomas of the corpus or the antrum, cardia carcinomas of intestinal type are associated with histologic changes in the gastric mucosa. The possibility that these changes are evoked by environmental factors was entertained.

Journal Article↗
PubMedDate not supplied

Pathological changes of advanced lower-rectal cancer by preoperative radiotherapy.

BACKGROUND/AIMS: In the treatment of lower rectal cancer, we examined the pathological effects of preoperative radiotherapy on intramural spread of tumor and risk factors for local recurrence, including tumor deposit, budding growth of primary tumors, and micrometastasis to lymph nodes. METHODOLOGY: Ninety-four patients who underwent surgery for lower rectal cancer were selected. Forty-seven patients received preoperative radiotherapy, at a total dose of 50 Gy [Rad(+) group], whereas 47 did not [Rad(-) group]. Intramural spread was evaluated between the Rad(+) and Rad(-) groups. For analysis of tumor deposit, budding, and micrometastasis, 25 stage-matched patients were selected in both groups. RESULTS: Intramural spread was significantly less in the Rad(+) group, compared with the Rad(-) group. The Rad(+) group showed a significant decrease in tumor deposit, budding, and micrometastasis, compared with the Rad(-) group. In patients having overt lymph node metastases or not, the tumor deposit and budding were significantly higher in patients having overt metastases, compared with those not having them, in the Rad(-) group, whereas there was no significant difference in the Rad(+) group. CONCLUSIONS: Intramural spread and tumor deposit, budding, and micrometastasis were significantly decreased in the Rad(+) group, compared with the Rad(-) group. These results suggested effects of preoperative radiotherapy for sphincter preservation, as well as for decreasing the local recurrence rate.

Adult↗
PubMedDate not supplied

Endoscopic total layer resection with laparoscopic sentinel node dissection and defect closure for duodenal carcinoid.

Tiny duodenal carcinoid is easily treated by endoscopic mucosal resection method. On the other hand, this tumor develops in the deeper layer of the mucosa, therefore it invades like a submucosal tumor. The resection of the total layer is sometimes needed to get a tumor-free margin. Moreover, lymph node metastasis is not predicted only by tumor size. Laparoscopic surgery is less invasive compared with conventional open surgery. We describe a new method, endoscopic total layer resection with laparoscopic sentinel node dissection and defect closure. This type of combined method should be performed in order to help decide whether to convert to conventional lymph node dissection, or not.

Carcinoid Tumor↗