History Of Colorectal Carcinoma Research Articles

No evidence for increased prevalence of colorectal carcinoma in 399 Dutch patients with Birt-Hogg-Dub\xe9 syndrome

BackgroundPreviously, it has been suggested that colorectal polyps and carcinomas might be associated with Birt-Hogg-Dubé syndrome. We aimed to compare the occurrence of colorectal neoplasms between Dutch patients with Birt-Hogg-Dubé syndrome and their relatives without Birt-Hogg-Dubé syndrome.MethodsIn all, 399 patients with a pathogenic FLCN mutation and 382 relatives without the familial FLCN mutation were included. Anonymous data on colon and rectum pathology was provided by PALGA: the Dutch Pathology Registry.ResultsNo significant difference in the percentage of individuals with a history of colorectal carcinoma was found between the two groups (3.6% vs 2.6%, p = 0.54). There was also no significant difference between the age at diagnosis, diameter, differentiation and location of the colorectal carcinomas. Significantly more individuals with Birt-Hogg-Dubé syndrome underwent removal of colorectal polyps (12.2% vs 6.3%, p = 0.005). However, there was no significant difference between the number of polyps per person, the histology, grade of dysplasia and location of the polyps.ConclusionOur data do not provide evidence for an increased risk for colorectal carcinoma in Birt-Hogg-Dubé syndrome, arguing against the need for colorectal surveillance. The difference in polyps might be due to a bias caused by a higher number of colonoscopies in patients with Birt-Hogg-Dubé syndrome.

Metastatic colorectal adenocarcinoma in a 76-year old male: a pitfall in the diagnosis for unclassified renal cell carcinoma

BackgroundThe kidney is the most common site of metastatic disease to the urinary tract. However, tumor characteristics are commonly deceptive, and the diagnosis of metastatic disease to the kidney may be challenging.Case presentationA 76- year old male was submitted to a total left nephrectomy with splenectomy due to pyonephrosis. At gross examination, the kidney presented a distorted anatomy, with firm parenchyma and an extensively necrotic lesion occupying the renal pyelo-calix and ureter. The spleen had a white pericapsular lesion measuring 1.2 cm. Histologic sections demonstrated a high grade solid carcinoma with rare areas of tubular differentiation. The tumor was highly infiltrative, with invasion of the renal sinus, perirenal fat and spleen. Considering the tumor location, high grade and infiltrative growth pattern, the diagnostic hypothesis of collecting duct carcinoma and urothelial carcinoma were drawn and investigated. Furthermore, a suspicion of metastatic disease was raised after a thorough investigation of the patient’s chart, which revealed a previous history of colorectal carcinoma 4 years earlier. Immunohistochemical studies demonstrated expression of CK20 and CDX-2 and negativity for CK7, CK5, PAX-8, Vimentin, CD117, GATA3 and p63; therefore, the patient was diagnosed with a poorly differentiated metastatic colorectal adenocarcinoma.ConclusionA high degree of suspicion is necessary for the diagnosis of metastatic disease to the kidney, which should ruled out before the final diagnosis of an unclassified renal cell carcinoma. A careful examination of the patient’s history and adequate communication with the attending physician is recommended for the correct diagnosis of these cases.

The clinical significance and synchronous polyp burden of large (≥ 20 mm) sessile serrated polyps in patients without serrated polyposis syndrome.

Sessile serrated polyps (SSPs) are important precursors of colorectal carcinoma and interval cancer. Large SSPs (≥ 20 mm) outside the definition of serrated polyposis syndrome (SPS) have not been studied in comparison with SPS. We aimed to describe the characteristics of patients with large SSPs in this context. Patients with at least one SSP (≥ 20 mm) were eligible. Data from three consecutive colonoscopies were used to compare clinical and endoscopic characteristics in three patient groups: SPS, a solitary large SSP, and patients with at least two SSPs without fulfilling the criteria for SPS (oligo-SSP). Data on the diagnostic colonoscopy were collected retrospectively, whereas the remaining data was collected prospectively. 67/146 patients (45.9 %) had SPS, 53/146 (36.3 %) had a solitary SSP, and 26/146 (17.8 %) were categorized as oligo-SSP. Personal (16.4 %, 9.4 %, and 11.5 %, respectively) and family (17.9 %, 17.0 %, and 23.1 %, respectively) history of colorectal carcinoma did not differ significantly between groups. Polyp burden was greater in SPS compared with solitary SSP but was not different from oligo-SSP (advanced adenomas: SPS 32.8 % vs. solitary SSP 9.4 % [P = 0.002] vs. oligo-SSP 34.6 % [P = 0.87]; ≥ 10 conventional adenomas: 11.9 % vs. 0 % [P = 0.01] vs. 3.8 % [P = 0.44], respectively). Dysplasia in large SSPs was frequent in all groups (41.1 % overall). SPS was recognized by referring endoscopists in only 9.0 % of cases. Patients with oligo-SSPs have similar synchronous polyp burden and clinical characteristics as patients with SPS and may require similar surveillance. Modification of the criteria for the diagnosis of SPS to include this group seems warranted. Patients with a solitary SSP have a lower risk of synchronous polyps, including advanced adenomas. Larger studies are warranted to determine whether these patients may return to standard surveillance following complete examination and clearance of the colon.

Rare Metastasis of Colon Carcinoma Mimicking Endometrial Cancer

Background: Colon cancer rarely mimics colon cancer, given that this type of cancer rarely metastasizes to the female genital tract. This case report describes a rare recurrence of colon cancer presenting with symptoms of primary endometrial cancer. Case: A 40-year-old woman had undergone colon resection for sigmoid-colon cancer 4 years prior to being admitted to the current authors' gynecology clinic because she had vaginal bleeding. An endometrial biopsy revealed metastases of colon adenocarsinoma. As noted on whole-body positron emission tomography/computerized tomography (PET /CT), the hypermethabolic malign involvement was located only in the patient's endometrium. Total abdominal hysterectomy and bilateral salpingo-opherectomy (TAH+BSO) was performed. Based on the pathologic examination of specimen that was removed surgically, a final diagnosis of sigmoid-colon cancer metastasis was confirmed. Results: Follow-up PET/CT did not show any evidence of malignancy. Conclusions: When a patient presents with abnormal vaginal bleeding and has a history of colorectal carcinoma, an unusual metastasis to the endometrium should be considered. (J GYNECOL SURG 29:262)

Double heterozygosity for BRCA1 and hMLH1 gene mutations in a 46-year-old woman with five primary tumors

Germline mutations in BRCA1 and BRCA2 genes predispose to hereditary breast cancer, whereas carriers of mutations in any of the mismatch repair genes (MMR; hMLH1, hMSH2, hMSH6, hPMS2) are highly susceptible to Lynch syndrome. In the present study, we describe a woman affected by unilateral breast cancer at the age of 35years. After 4years, during the follow-up she developed synchronous (and asymptomatic) endometrial cancer, ovarian carcinoma and renal clear cell carcinoma. After 7years (at age 46), the patient developed an infiltrating carcinoma of the contralateral breast and died in a few months of metastatic disease. Initial investigations led to the detection of a constitutional mutation in the BRCA1 gene. The extended genealogical tree disclosed a suspected history of colorectal carcinoma in the maternal branch. Endometrial cancer of the proband was investigated for microsatellite instability (MSI) and immunohistochemical expression of MLH1, MSH2 and MSH6 proteins. An high MSI status and lack of expression of MLH1 protein were detected. hMLH1 gene sequencing revealed the presence of a constitutional mutation, which was also found in the mother of the proband. Loss of the wild-type hMLH1 allele was detected in both breast tumors, thus suggesting that the MMR defect contributed to the development of the breast cancer.

A rare metastases of a colorectal primary to the clavicle

INTRODUCTIONColorectal cancer is the third commonest cancer in the UK. The commonest site of colorectal cancer metastases is the liver, followed by lungs. Metastases to small bones are recognized but are a rare occurrence of colorectal malignancy. PRESENTATION OF CASEA 92 year old lady presented with a swollen, fractured right clavicle following a fall. On follow up, a swelling of approximately 10cm was still noted in the area. A CT scan revealed a ten by ten centimetres mass arising from the clavicle and a 9cm mass arising from the left aspect of the sacrum. She was also found to have complete collapse of the left lung with an underlying mass and a mass within the right lung. Biopsy of the clavicular mass was suggestive of metastatic colorectal adenocarcinoma. She had undergone an anterior resection for Dukes C adenocarcinoma six years previously. DISCUSSIONThis case demonstrates the rare metastases of a colorectal primary to the clavicle, a clavicle metastases of this size has not been previously reported in literature. CONCLUSIONA high index of suspicion for potential of small bone metastases has to be entertained in a patient presenting with a non-healing fracture and a history of colorectal carcinoma.

Embolización directa de varices estomales en la hipertensión portal tras el tratamiento de metástasis hepáticas

We present the case of a man with a history of colorectal carcinoma and metastatic liver involvement who developed portal hypertension and recurrent bleeding from stomal varices after treatment with intra-arterial oxaliplatin and radioembolization with yttrium-90 microspheres. The definitive treatment for the bleeding episodes was embolization of the varices with coils using a direct percutaneous approach.

Endobronchial colorectal metastasis versus primary lung cancer: a tale of two sleeve right upper lobectomies

Endobronchial metastasis from colorectal carcinoma is relatively uncommon whereas primary bronchogenic carcinoma is more common. These two disease entities can both appear to be similar clinically and radiographically. Palliative treatment rather than a curative-intent anatomic resection is typically employed in the setting of endobronchial metastatic disease. We compare two cases of patients with a history of colorectal carcinoma with endobronchial lesions of which one was truly a metastatic lesion.

MR colonography for the assessment of colonic anastomoses

To assess colonic anastomoses in patients after surgical treatment by means of MR colonography (MRC) in comparison with conventional colonoscopy (CC). A total of 39 patients who had previously undergone colonic resection and end-to-end-anastomosis were included in the study. MRI was based on a dark-lumen approach. Contrast-enhanced T1-weighted (T1w) three-dimensional (3D) images were collected following the rectal administration of water for colonic distension. The MRC data were evaluated by two radiologists. The criteria employed to evaluate the anastomoses included bowel wall thickening and increased contrast uptake in this region. Furthermore, all other colonic segments were assessed for the presence of pathologies. In 23 and 20 patients the anastomosis was rated to be normal by MRC and CC, respectively. In three patients CC revealed a slight inflammation of the anastomosis that was missed by MRI. A moderate stenosis of the anastomosis without inflammation was detected by MRC in five patients, which was confirmed by CC. In the remaining 11 patients a relevant pathology of the anastomosis was diagnosed by both MRC and CC. Recurrent tumor was diagnosed in two patients with a history of colorectal carcinoma. In the other nine patients inflammation of the anastomosis was seen in seven with Crohn's disease (CD) and two with ulcerative colitis. MRC did not yield any false-positive findings, resulting in an overall sensitivity/specificity for the assessment of the anastomosis of 84%/100%. MRC represents a promising alternative to CC for the assessment of colonic anastomoses in patients with previous colonic resection.

FDG-PET scanning in the diagnosis of gastrointestinal cancers

This review deals with the current, well-established indications for two-([Formula: See Text]F)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) scanning in patients with gastrointestinal cancers. FDG-PET is a non-invasive, functional imaging technique. FDG exploits the native glucose transporter to enter the cell. Since many tumours have enhanced glucose uptake, FDG is readily accumulated in malignant cells and can be detected by a PET camera. FDG-PET has been established as an important diagnostic tool in clinical oncology. This review deals with the current, well-established indications for FDG-PET scanning in patients with gastrointestinal cancers. In the current practice, FDG-PET is most commonly used to stage oesophageal carcinoma, to detect and stage recurrence of colorectal carcinoma and to differentiate between benign and malignant pancreatic lesions. The benefit of FDG-PET scanning in patients with oesophagus carcinoma is best established in stage IV disease, as the diagnostic accuracy to detect metastatic disease is higher compared to the combination of computed tomography (CT) and endoscopic ultrasound (EUS). In patients with a history of colorectal carcinoma, FDG-PET scanning is particularly effective in diagnosing recurrent disease, especially in those with a rising carcinoembryonic antigen without a suspect lesion on conventional imaging. Large series have indicated that the sensitivity and specificity for detecting recurrent colorectal carcinoma are in the range of 87%-100% and 66%-100%, respectively. Equally, FDG-PET has a high sensitivity (68%-96%) and specificity (78%-100%) in detecting pancreatic carcinoma in patients with a suspicious-looking pancreatic mass on CT scan. Lastly, we focus on the use of FDG-PET as a modality for early monitoring of treatment response in patients with gastrointestinal stromal cell tumours. Without doubt, future developments will further establish the diagnostic role of the FDG-PET scan in the care of patients with gastrointestinal cancers.

Colon cancer metastasis to small bowel detected by capsule endoscopy

A 78 year-old male with history of colorectal carcinoma, diagnosed in 1997, surgically removed with negative lymph nodes. Four years later the patient developed a local recurrence without any metastasis, with positive lymph nodes. The patient underwent radiation and chemotherapy. He remained asymptomatic with normal lab. work up until last year when he presented with intermittent bouts of crampy abdominal pain and constipation, experiencing relief with self induced vomiting. These episodes grew more frequent and the patient then presented a drop in his hgb from 13 to 11.8g/dl with melena. At this time an EGD and colonoscopy were normal. Abdomino-pelvic CT Scan was also non diagnostic as was an UGIS's. After intestinal obstruction was excluded, capsule endoscopy was performed. The study showed a clear area of active oozing of blood associated to an ulcerated mass at the jejunum. The patient was refered for surgery. The only finding was the lesion originally detected by the capsule at the jejunum. It was resected followed by an end to end anastomosis. The histologic analysis of the mass revealed it to be a metastatic lesion from prior colon cancer, with spread limited to the small bowel. This is to our knowledge the first case of a colonic metastatic solitary lesion to the small bowel detected by the M2A endoscopic capsule. This finding shows that wireless endoscopy is an invaluable tool in cases of obscure GI bleeding as well as in chronic abdominal pain. It is noteworthy that in this case that the patient had two prior abdominal surgeries, and the possibility of partial small bowel obstruction secondary to adhesions was entertained. There is still controversy regarding the use of endoscopic capsule in that setting, but we think that the only absolute contraindication would be a patient who refuses to have surgery or who has serious contrindications for surgery should it become necessary to remove a capsule retained in an obstructed bowel. In this case, the prompt diagnostic approach with the M2A made early intervention possible due to the finding of the ulcerated mass where all other modalities were non-diagnostic. Without the use of the capsule endoscope, this patient may have gone undiagnosed for a long time allowing for progression of the metastasis. In conclusion, if there is a clinical suspicion that small bowel pathology is causing the patient's problem, M2A endoscopic capsule technology should be used more frequently and liberally in the early phases of the work up.

Incidental colonic fluorodeoxyglucose uptake: correlation with colonoscopic and histopathologic findings.

To evaluate the pattern and degree of incidental colonic fluorodeoxyglucose (FDG) uptake in patients without colorectal carcinoma who underwent whole-body FDG positron emission tomography (PET) for other purposes and compare them with colonoscopic and/or histopathologic findings. Cases of 27 patients without known history of colorectal carcinoma who were referred for evaluation with whole-body FDG PET and displayed incidental colonic uptake were reviewed retrospectively. Colonoscopy was performed in 10 patients; histopathologic analysis, in two; and both, in 15. The colonic FDG uptake patterns were nodular-focal, nodular-multifocal, segmental, and diffuse. The FDG uptake level was scored with a four-point scale in relation to hepatic uptake. Binomial distribution was used to calculate 95% CIs for the probability of finding an abnormality at histologic examination, as predicted by findings at FDG PET. Colonoscopic findings in eight patients with a diffuse uptake pattern were normal. Thirteen patients with nodular high FDG uptake had pathologic findings. Six (22%) of the 27 patients were not suspected of having a malignancy, and seven had benign neoplasms. With a 95% CI, nodular high FDG uptake implies at least a 79% chance that histopathologic findings may be abnormal. Colitis was seen in five of six patients with a segmental pattern of high FDG uptake. Colonoscopy is a reasonable next step for further diagnostic examination of patients who display nodular high FDG uptake in the colon. Diffuse FDG uptake often is associated with normal findings at colonoscopy, while segmental high uptake may imply inflammation.

Conservative treatment of tracheal rupture

J Thorac Cardiovasc Surg 1999;117:399-401

Ovarian and uterine disease in women with colorectal cancer

To identify the nature of adnexal and uterine disease in women with a history of colorectal adenocarcinoma who develop new pelvic masses or uterine cancers during follow-up. We conducted a retrospective chart review of the Memorial Hospital Gynecology Service database and identified 50 women, each with a history of colorectal carcinoma who underwent a hysterectomy or adnexectomy between January 1, 1977, and February 29, 1996. Subject characteristics, indications for re-operation, and findings at surgery were recorded. The mean age at re-operation was 66 years (range, 37-76), with a median interval from initial diagnosis to re-operation of 25 months (range, 3-444). Indications for re-operation were: 1) new pelvic mass in 35 women, and 2) cancer on endometrial or cervical biopsy in 15. Twenty-six of the 35 (74%) women who presented with a pelvic mass had a malignancy in the ovary, with metastatic colon cancer noted in 20 of 26 (77%) women, and epithelial ovarian cancer in six of 26 (23%). The mean ovarian tumor size for metastatic colorectal carcinoma, ovarian cancer, and benign tumors was 15, 8, and 6 cm, respectively. Fifteen women underwent hysterectomy for a newly diagnosed cancer in the uterus, with the majority, 11 (73%), having endometrial adenocarcinoma, followed by metastatic colon cancer to the endometrium or cervix in three (20%) women, and primary cervical carcinoma in one. Women with a history of colorectal cancer who underwent adnexectomy for a new pelvic mass had metastatic colon cancer to the ovary in 57%, benign ovarian neoplasm in 26%, and primary ovarian cancer in 17% of cases. Women who underwent hysterectomy for a newly diagnosed carcinoma in the uterus had primary endometrial adenocarcinoma in 73% and metastatic colon cancer in 20% of cases.

Codon 201Arg/Gly polymorphism of DCC (deleted in colorectal carcinoma) gene in flat- and polypoid-type colorectal tumors.

Recent studies have identified the distinct existence of flat-type colorectal tumors. The low incidence of ras gene mutations in these tumors suggests that their genetic pathways of tumor progression may be different from those of the polypoid type. To elucidate further genetic alterations in flat-type colorectal tumors, codon 201Arg/Gly polymorphism in the DCC (deleted in colorectal carcinoma) gene was analyzed in normal tissue (normal colonic mucosa or peripheral lymphocytes) and in tumor tissue from 191 patients with colorectal tumors (36 patients with flat-type colorectal tumors, 81 patients with polypoid-type colorectal tumors, and 74 patients with advanced carcinomas). For normal controls, 30 samples obtained from patients who had neither colorectal tumors (confirmed by total colonoscopy) nor a family history of colorectal carcinoma were analyzed. DCC gene codon 201Arg/Gly polymorphism was investigated by polymerase chain reaction-based restriction fragment length polymorphism analysis, fluorescence-based dideoxy sequencing, or both. For the flat type, the frequency of codon 201Gly of the DCC gene was 64% and 54% in the normal tissue of patients with adenoma with high-grade dysplasia and submucosal carcinoma, respectively. It was 49%, 52%, and 49% in the normal tissue of patients with polypoid-type adenoma with high-grade dysplasia, submucosal carcinoma, and advanced carcinoma, respectively. In the normal tissue, codon 201Gly of the DCC gene was more frequently observed in patients with flat-type adenoma with low-grade dysplasia (67%) than in those with polypoid-type adenoma with low-grade dysplasia (18%) or in normal controls (17%, P < 0.05, chi2 test). Codon 201Arg/Gly polymorphism in tumor tissues did not differ from that in the corresponding normal tissues, except for 10 cases of carcinoma with loss of heterozygosity (LOH). In carcinomas with LOH, preferential loss of the codon 201Arg allele was noted (9/10 cases). These results suggest that codon 201Gly of the DCC gene is not only associated with flat-type colorectal tumors, but that it may serve as a useful genetic marker for identifying groups at higher risk for colorectal cancer.

Molecular genetic differentiation between primary lung cancers and lung metastases of other tumors

When solitary pulmonary tumors are observed in patients with a history of cancer, differentiation between metastasis and primary lung cancer is crucial for appropriate therapy. Assuming that p53 mutations are conserved in metastases, mutation analysis of the p53 gene would be a valuable tool in differentiating metastases from primary carcinomas of the lung. In nine of 267 resected lung tumors, the origin of the lung tumor could not be defined histologically. Five patients had a history of colorectal carcinoma, one had a history of breast carcinoma, one had a history of soft-tissue carcinoma, and one had a history of head and neck carcinoma. One patient with a clear cell carcinoma of the lung had been surgically treated for both renal and thyroid cancer. Material from one patient with adenocarcinoma of the lung, histologically defined regional lymph nodes, and distant brain metastasis served as a control. We extracted deoxyribonucleic acid from the snap-frozen tissue of the unclassified lung tumors, from paraffin-embedded tissue of the previously removed primary cancers, and also from peripheral blood of the patients. Exons 2 to 11 of the p53 gene were amplified in separated polymerase chain reactions and directly sequenced. In all cases, the presence of germline mutations was excluded by analysis of peripheral blood deoxyribonucleic acid. The p53 mutation detected in the deoxyribonucleic acid of the lung tumor of the control patient proved to be conserved in the lymph nodes as well as in the brain metastasis. In two cases, the lung tumors exhibited a p53 mutation not present in the previously removed primary tumor and were therefore classified as new primary lung cancers. In five cases, the lung tumors proved to be metastases of the first tumor, exhibiting the identical p53 mutation. One of these lung tumor samples could be identified as a metastasis from the renal cancer, but the corresponding thyroid cancer material was different. For two cases, molecular analysis remained inconclusive. In one case, no p53 mutation could be found in the compared samples; in the other, no deoxyribonucleic acid could be extracted. Analysis of p53 mutations allowed exact classification in tumors for which standard methods failed to distinguish between metastasis or primary tumor. More than two thirds of lung tumors in patients with previous gastrointestinal carcinoma were revealed to be metastases, but second primary lung cancer could also be diagnosed. This diagnosis allowed correct surgical and adjuvant treatment of these patients. (J T HORAC C ARDIOVASC S URG 1996;111:827-32)

Comments on hematogenous metastatic patterns in humans as revealed by autopsy.

An attempt is made to clarify some general concepts of hematogenous metastatic patterns in humans, by the use of autopsy data. The significance and problems associated with 'false negative' reports are assessed. By the use of metastatic efficiency indices in which the incidence of specific target organ involvement is related to organ blood-flow, 'seed-and-soil' effects are discriminated from the effects of differential cancer cell delivery. An analysis of autopsy data from cases with a history of colorectal carcinoma is used to illustrate the importance of metastasis from metastases in the genesis of hematogenous metastatic patterns in humans.

Clinicopathologic features of the flat adenoma

One hundred twenty-eight small flat adenomas (SFAs) were collected from 101 patients, and the clinicopathologic features were investigated. There were 91 adenomas with mild atypia, 20 with moderate atypia, and 17 with severe atypia. SFAs were found more often in males than in females, with a ratio of 3.4:1, and the malignancy rate in females (31.8 percent) was higher than in males (9.3 percent). About 38 percent of the patients had a history of colorectal carcinoma, and 65 percent had a history of colorectal neoplasms. Of 37 patients whose family history was traced, 21 had cancer families. SFAs were prone to be found in patients with a history of colorectal neoplasms and a cancer family. Malignancy rate increased with increasing size. The overall malignancy rate was 13.3 percent, which was considerably higher than that of ordinary small polypoid adenomas (2.8 percent). SFAs were situated more proximally (30.9 percent) than ordinary adenomas; however, there was no relationship between site and malignancy. All the lesions showed tubular adenomas, and there was no villous feature. A central depression was noted in 20 lesions, more frequently in adenomas with higher atypia. All but one adenoma with severe atypia showed a component of lower atypia, supporting the adenoma-carcinoma sequence.

Surveillance Colonoscopy After Resection for Colon Carcinoma

Periodic surveillance colonoscopy was used to assess 207 asymptomatic patients with a previous history of colorectal carcinoma for 2 to 8 years. Thirty-five percent of the patients had a neoplastic lesion greater than or equal to 5 mm in diameter on initial colonoscopy. Synchronous or metachronous carcinomas were found in 11 patients; and of these second carcinomas, 82% were localized. The risk of a second carcinoma developing did not correlate with a finding of neoplastic polyps on the initial colonoscopy. Six recurrent carcinomas at the anastomosis were demonstrated. The stage of the recurrence correlated well with the stage of the primary carcinoma. Two negative colonoscopies at 1-year intervals were necessary to ensure that the colon had been cleared of neoplastic lesions. This study shows that surveillance colonoscopy in patients with a history of colorectal carcinoma has a high yield and is capable of detecting localized, asymptomatic carcinoma. After two annual colonoscopies fail to show neoplasms, surveillance colonoscopy may be scheduled at 3- to 5-year intervals.

Colorectal adenomas: morphologic features and the risk of developing metachronous adenomas and carcinomas in the colorectum.

The morphologic features of 307 colorectal adenomas among 159 patients are reviewed. Most adenomas (66.4%) were located in the sigmoid colon and the rectum, and the percentage decreased proximally to the right colon. The 307 adenomas comprised 244 (79.5%) tubular, 41 (13.3%) tubulovillous, and 22 (7.2%) villous adenomas. The epithelial dysplasia was graded as mild in 260 (84.7%) adenomas, moderate in 33 (10.7%), and severe in 14 (4.6%). The percentage of severe dysplasia was greater in villous adenomas than in tubular adenomas (p less than 0.05) and correlated with the increasing size (greater than 5 mm) of the adenomas (p less than 0.01). The risk of metachronous adenomas could be evaluated among 56 patients, 34 men and 22 women with a history of removed adenoma(s). Fourteen of 56 patients (25%) with 6:1 male to female ratio developed 18 new adenomas, after an average of 34.3 months (range, from 12 to 88 months). Eleven of the 14 patients had multiple adenomas at the initial examination. In addition, a carcinoma of the rectum was found in one male patient. Of the 48 patients, 17 men and 31 women, operated on for colorectal cancer 16 patients (34%) with 1.3:1 male to female ratio had 40 new adenomas after an average of 51.8 months (range, 12 to 252 months) after the surgical excision of their carcinomas. One patient had a recurrent carcinoma at the site of the anastomosis 22 months after anterior resection of his carcinoma. Our data suggest that a history of colorectal carcinoma, multiple adenomas, and male sex predict a higher risk of having future colorectal tumours.