One of the most critical characteristics of colorectal cancer (CRC) is the difference between proximal (right-sided colon cancer, RCC) and distal (left-sided colon cancer, LCC) disease. The recent CRC studies showed the unique characteristics of RCC; RCCs were more prevalent in women than men and old patients, and the age difference between RCC and LCC was more apparent in women. Moreover, relatively poor protection against RCC by colonoscopy is a clearly hot issue for alarm. Thus, the left and right colon have been considered as dichotomous or even different organs in the view of molecular, histopathological, epidemiologic and clinical bases for over three decades. However, the evolutionary data suggesting linearity from the rectum to ascending colon beyond the simple right-left dichotomization in the views of cancer molecular features and site-specific clinicopathological differences, support the need for a paradigm shift to the colorectal continuum model rather than the traditional two-colon concept. This new multi-segmental or colorectal continuum hypothesis would provide both the better understanding of the complex etiology of colorectal carcinogenesis and the tailored preventive and therapeutic strategies for CRC including individualized CRC screening programs.
Adenoma/pathology ; Age Factors ; Colon, Ascending/pathology ; Colon, Descending/pathology ; Colorectal Neoplasms/genetics/*pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Sex Factors

Adolescent ; Colon, Ascending ; pathology ; Colonic Neoplasms ; pathology ; surgery ; Colonic Polyps ; pathology ; surgery ; Diagnosis, Differential ; Follow-Up Studies ; Ganglioneuroma ; pathology ; surgery ; Humans ; Male

Schwannomas are rare tumors derived from the cells of Schwann which form the neural sheath. Some patients with gastrointestinal schwannoma have been previously reported in the literature. However, schwannomas of the colon are extremely rare. We herein describe a case of schwannoma of the colon. A 49-year-old woman was admitted with complaint of abdominal pain and investigations revealed the presence of a 4 cm sized mass in the ascending colon. Following right hemicolectomy, histopathology and immunohistochemistry confirmed the colonic lesion to be a benign schwannoma. There was no evidence of specific complication or recurrence until now.
Colon, Ascending/*pathology ; Colonic Neoplasms/*diagnosis/pathology/ultrasonography ; Female ; Humans ; Middle Aged ; Neurilemmoma/*diagnosis/pathology/ultrasonography ; S100 Proteins/analysis/immunology ; Tomography, X-Ray Computed

OBJECTIVETo compare the difference of the diameters of superior mesenteric vein (SMV) and gastrocolic trunk (GCT) between patients with cecum-ascending colon cancer and normal individuals, and to assess the diagnostic value of the diameters of SMV and GCT in cecum-ascending colon cancer.

METHODSPreoperative imaging data of 60 patients with primary cecum-ascending colon cancer confirmed by postoperative pathology at the First Affiliated Hospital of Sun Yat-sen University from June 2014 to December 2016 were retrospectively analyzed. The diameters of SMV and GCT were measured on preoperative CT images. SMV was measured at about 2 cm below the junction of SMV and splenic vein. GCT was measured at 1 cm near the proximal junction of right colon vein, right gastroepiploic vein and anterior pancreaticoduodenal vein. Another 60 people receiving pelvic CT examination without organ illness were collected as control. The diameter differences of SMV and GCT between cancer group and control group were compared. The diagnostic value of the diameters of SMV and GCT in cecum-ascending colon cancer was evaluated by receiver operating characteristic (ROC) curves.

RESULTSAmong 60 cases of cecum-ascending colon cancer, 36 were males and 24 were females with median age of 48 years (range 28-84); 13 were cecum cancer, 47 were ascending colon cancer; 11 had no lymph node and liver metastasis, 40 had lymph node metastasis, 9 had liver metastasis (all with lymph node metastasis). Compared to control group, the diameters of SMV and GCT in cancer group were significantly longer [SMV:(11.2±1.3) mm vs. (9.5±1.7) mm, t=6.04, P<0.001; GCT:(5.5±0.9) mm vs. (3.5±1.0) mm, t=11.51, P<0.001]. However, there were no statistically significant differences in diameters of SMV and GCT among hepatic metastasis, lymph node metastasis and no metastasis cancer groups (all P>0.05). The ROC curve analysis showed that the area under the curve of SMV diameter was 0.777, and the optimal cut-off point was 10.5 mm in the diagnosis of cecum-ascending colon cancer, with the sensitivity and specificity of 95.0%(57/60) and 46.7%(28/60) respectively. The area under the curve of GCT diameter was 0.923, and the optimal cut-off point was 4.5 mm in the diagnosis of cecum-ascending colon cancer, with sensitivity and specificity of 88.3%(53/60) and 85.0%(51/60) respectively.

CONCLUSIONThe dilation of the SMV and GCT may be used as warning factors for cecum-ascending colon cancer, especially the diameter of GCT.

Adult ; Aged ; Aged, 80 and over ; Cecum ; Colon, Ascending ; pathology ; Colonic Neoplasms ; pathology ; Female ; Humans ; Male ; Mesenteric Veins ; anatomy & histology ; Middle Aged ; Retrospective Studies

BACKGROUND/AIMS: Ischemic colitis (IC) usually occurs in the elderly population and has a various clinical presentations from mild to severe forms. The aim of this study was to investigate the clinical outcomes according to the involved sites and colonoscopic findings in IC. METHODS: We retrospectively analyzed the medical records of 77 patients who had diagnosed with IC between January 2000 and July 2010. The clinical outcomes were compared according to numbers of the involved segments, location and endoscopic findings. RESULTS: Mean age of the patients was 70+/-11 years and male to female ratio was 1:1.26. Hematochezia (67.5%) and abdominal pain (63.6%) were the most common associated symptoms. The colonoscopic examination was performed at mean 4.6+/-3.7 days after the symptom onset. The most common involved segment was the sigmoid colon (72.7%). Duration of fasting, antibiotics therapy, hospital stay and mortality were significantly increased in the patients group with more involved segments (p<0.001, p=0.004, p<0.001, p<0.001, respectively). Duration of antibiotics therapy and hospital stay were significantly longer in the right colon involvement group (p=0.038, p=0.002, respectively). The time taken until the alleviation of symptoms and the white blood cells count were significantly longer and higher in the ulcer or gangrenous group (p=0.001, p=0.022, respectively). CONCLUSIONS: Evaluating the involved sites, the degree and severity of mucosal damage by colonoscopy may be important in predicting the clinical course and prognosis of the patients with IC. Early detection, careful monitoring and prompt treatment are crucial especially in the patients with ulcer or necrosis in colonscopic findings.
Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/therapeutic use ; Colitis, Ischemic/*diagnosis/drug therapy/mortality ; Colon, Ascending/pathology ; Colon, Sigmoid/pathology ; Colonoscopy ; Female ; Humans ; Length of Stay ; Leukocyte Count ; Male ; Middle Aged ; Predictive Value of Tests ; Retrospective Studies

OBJECTIVETo discuss surgical treatment of right colon carcinoma of hepatic flexure invading the duodenum.

METHODSSixty-five patients with right colon carcinoma of hepatic flexure invading the duodenum, treated in our department from 1987 to 2007, were included in this study. Their clinicopathological data were retrospectively reviewed and analyzed. All the cases were divided into three types (local invasion, regional invasion, and cancer with internal fistula) according to duodenal defect, including local invasion (< 2.0 cm), wide invasion (> 2.0 cm) and the presence of internal fistula.

RESULTS25 patients with local invasion underwent en bloc resection of the duodenal wall. Pedicled ileal flap was used to cover the large duodenal defect measuring 2.0 - 3.0 cm in 5 patients. Dudenojejunostomy was used to reconstruct the large defect measuring more than 5 cm in 3 patients. Conservative resection of right-sided colon was performed in 18 patients with wide invasion. 4 patients underwent pancreaticoduodenectomy combined with right hemicolectomy for colon cancer involving the pancreatic head. 10 underwent duodenal diverticularization. One patient with anastomotic leakage healed within 3 weeks. Other patients were cured without postoperative complications. The total 3-year and 5-year survival rates after surgery were 53.8% and 9.2%, respectively.

CONCLUSIONThe surgical procedure to be performed is usually decided according to the cancer location, extent, and duodenal defect and invasion, which are important for prolonging life time, improving of quality of life and prognosis in these patients.

Adenocarcinoma ; pathology ; surgery ; Adenocarcinoma, Mucinous ; pathology ; surgery ; Adult ; Aged ; Colectomy ; methods ; Colon, Ascending ; pathology ; surgery ; Colonic Neoplasms ; pathology ; surgery ; Duodenum ; pathology ; surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Neoplasm Invasiveness ; Pancreaticoduodenectomy ; Quality of Life ; Retrospective Studies ; Survival Rate

Primary squamous cell carcinoma of the colon is an extremely rare malignancy. A 48-year-old male visited our hospital for screening colonoscopy. Colonoscopic examination showed a 1 cm sized sessile polyp in the ascending colon. The patient underwent endoscopic mucosal resection (EMR) without any complication. The pathologic findings were compatible with squamous differentiation of tumor cells in inflammatory colonic mucosa. The tumor was confined to the mucosa and the margins of the excised tissue were found to be free of the tumor. There were no other primary sites and no distant metastases in the extensive evaluation using a whole body CT scan and PET-CT. Additional surgical resection was not done. Follow-up colonoscopy performed eight month later showed a whitish scar without evidence of local recurrence and follow-up PET-CT demonstrated no evidence of recurrence. Herein, we report a case of primary squamous cell carcinoma of the ascending colon presenting as a sessile polyp which was removed by EMR.
Adult ; Aged ; Asian Continental Ancestry Group ; Carcinoma, Squamous Cell/*diagnosis/pathology ; Colon, Ascending ; Colonic Neoplasms/*diagnosis/pathology ; Colonoscopy ; Female ; Humans ; Intestinal Mucosa/pathology/surgery ; Male ; Middle Aged ; Positron-Emission Tomography ; Republic of Korea ; Tomography, X-Ray Computed

OBJECTIVETo retrospectively analyze KRAS and BRAF gene mutation features in Chinese colorectal cancer (CRC) and their clinicopathologic relationship.

METHODS557 colorectal cancer cases were collected, including 325 colon cancer and 232 rectal cancer. PCR amplification and DNA sequencing were used to detect mutations in exon 2 of KRAS gene and exon 15 of BRAF gene mutation.

RESULTS(1) KRAS mutation was found in 40.4% (225/557) colorectal cancer. The most common mutation locations were in codon 12(79.1%, 178/225) and codon 13 (20.4%, 46/225). The most common mutation types were GGT > GAT (G12D) (37.8%, 85/225), GGT > GTT(G12V) (20.0%, 45/225) in codon 12 and GGC > GAC (G13D) in codon 13 (19.6%, 44/225). These three point mutations accounted 77.3% (174/225) in total KRAS gene mutation cases. All cases showed only one of point mutation types. (2) Among 557 CRC cases, KRAS mutation was significantly higher in female (46.2%, 92/199) than in man (37.2%, 133/358; P < 0.05). KRAS gene codon 13 mutation was higher in right colon cancer (11.3%, 12/106) than that in left colon cancer (4.8%, 6/124), but it didn't show any statistical significance (P > 0.05). (3) BRAF gene mutation was 5.1% (10/197) in colorectal cancer and 8/10 were the point mutation of GTG > GAG (V600E). Eight colorectal cancer cases with GTG > GAG (V600E) were not showing KRAS gene mutation. Both two cases with mutation on codon 600 (GTG > ATG, V600M) and codon 606 (GGG > AGT, G606S) showed codon 12 mutation of KRAS gene. (4) BRAF (V600E) gene mutation was higher in female (8.5%, 6/71) than that in male (1.6%, 2/126; P = 0.05); BRAF mutation in colon cancer (8.3%, 6/72) was higher than that in rectum cancer (2.1%, 2/94), but hadn't statistical significance (P > 0.05).

CONCLUSIONS(1) Codon 12, 13 in KRAS gene and codon 600 in BRAF gene are the most common mutation points in Chinese colorectal cancer. KRAS and BRAF mutations are mutually exclusive. (2) KRAS and BRAF gene mutation is higher in female than that in male, suggesting that RAS-RAF-MAPK signal pathway is probably related to hormones directly or indirectly. (3) There is a trend that codon 13 mutation in KRAS and codon 600 mutation in BRAF in right colon cancer are higher than that in left colon cancer, respectively, however, which needs more cases to be further verified.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; genetics ; Codon ; Colon, Ascending ; pathology ; Colon, Descending ; pathology ; Colonic Neoplasms ; genetics ; pathology ; Colorectal Neoplasms ; genetics ; pathology ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Proto-Oncogene Proteins ; genetics ; Proto-Oncogene Proteins B-raf ; genetics ; Proto-Oncogene Proteins p21(ras) ; Rectal Neoplasms ; genetics ; pathology ; Sex Factors ; Young Adult ; ras Proteins ; genetics