Effect of care continuity on mortality of patients readmitted after colorectal surgery.

BACKGROUND: Postoperative readmission after colorectal resection is common. It is unknown whether patients who receive readmission care from the surgeon who performed the index surgery have improved mortality. This study evaluated whether postdischarge continuity of care, defined at the hospital and surgeon level, was associated with decreased mortality after colorectal surgery. METHODS: The Statewide Planning and Research Cooperative System was queried for patients who had colorectal resections from 2004 to 2014, and were readmitted within 30 days of discharge. Propensity-adjusted logistic regression analysis was used to evaluate the association between 30-day mortality and readmission care continuity. RESULTS: A total of 20 016 patients readmitted within 30 days of discharge were eligible for analysis. Some 39·5 per cent of readmitted patients experienced hospital and surgeon care continuity, 47·1 per cent hospital but not surgeon continuity, 1·0 per cent surgeon but not hospital continuity, and 12·4 per cent neither hospital nor surgeon care continuity. A total of 1349 patients (6·7 per cent) died within 30 days of readmission. Patients readmitted with absence of surgeon but not of hospital care continuity had 2·04 (95 per cent c.i. 1·72 to 2·42) times the risk of 30-day mortality compared with those who experienced surgeon and hospital continuity. Absence of both surgeon and hospital care continuity was associated with 2·65 (2·18 to 3·30) times the risk of death compared with presence of both. CONCLUSION: Readmission after colorectal resection not under the care of the index operating surgeon is associated with an increased risk of 30-day mortality. Addressing processes of care that are affected by surgeon care continuity may decrease surgical deaths.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes.

AIM: Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes. METHOD: We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015. RESULTS: In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002). CONCLUSION: Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.

Effectiveness of a multidisciplinary patient care bundle for reducing surgical-site infections.

BACKGROUND: Surgical-site infection (SSI) is associated with significant healthcare costs. To reduce the high rate of SSI among patients undergoing colorectal surgery at a cancer centre, a comprehensive care bundle was implemented and its efficacy tested. METHODS: A pragmatic study involving three phases (baseline, implementation and sustainability) was conducted on patients treated consecutively between 2013 and 2016. The intervention included 13 components related to: bowel preparation; oral and intravenous antibiotic selection and administration; skin preparation, disinfection and hygiene; maintenance of normothermia during surgery; and use of clean instruments for closure. SSI risk was evaluated by means of a preoperative calculator, and effectiveness was assessed using interrupted time-series regression. RESULTS: In a population with a mean BMI of 30 kg/m2 , diabetes mellitus in 17·5 per cent, and smoking history in 49·3 per cent, SSI rates declined from 11·0 to 4·1 per cent following implementation of the intervention bundle (P = 0·001). The greatest reductions in SSI rates occurred in patients at intermediate or high risk of SSI: from 10·3 to 4·7 per cent (P = 0·006) and from 19 to 2 per cent (P < 0·001) respectively. Wound care modifications were very different in the implementation phase (43·2 versus 24·9 per cent baseline), including use of an overlying surface vacuum dressing (17·2 from 1·4 per cent baseline) or leaving wounds partially open (13·2 from 6·7 per cent baseline). As a result, the biggest difference was in wound-related rather than organ-space SSI. The median length of hospital stay decreased from 7 (i.q.r. 5-10) to 6 (5-9) days (P = 0·002). The greatest reduction in hospital stay was seen in patients at high risk of SSI: from 8 to 6 days (P < 0·001). SSI rates remained low (4·5 per cent) in the sustainability phase. CONCLUSION: Meaningful reductions in SSI can be achieved by implementing a multidisciplinary care bundle at a hospital-wide level.

Prognostic aspects of DCE-MRI in recurrent rectal cancer.

OBJECTIVE: To explore whether pre-reoperative dynamic contrast-enhanced (DCE)-MRI findings correlate with clinical outcome in patients who undergo surgical treatment for recurrent rectal carcinoma. METHODS: A retrospective study of DCE-MRI in patients with recurrent rectal cancer was performed after obtaining an IRB waiver. We queried our PACS from 1998 to 2012 for examinations performed for recurrent disease. Two radiologists in consensus outlined tumour regions of interest on perfusion images. We explored the correlation between K(trans), Kep, Ve, AUC90 and AUC180 with time to re-recurrence of tumour, overall survival and resection margin status. Univariate Cox PH models were used for survival, while univariate logistic regression was used for margin status. RESULTS: Among 58 patients with pre-treatment DCE-MRI who underwent resection, 36 went directly to surgery and 18 had positive margins. K(trans) (0.55, P = 0.012) and Kep (0.93, P = 0.04) were inversely correlated with positive margins. No significant correlations were noted between K(trans), Kep, Ve, AUC90 and AUC180 and overall survival or time to re-recurrence of tumour. CONCLUSION: K(trans) and Kep were significantly associated with clear resection margins; however overall survival and time to re-recurrence were not predicted. Such information might be helpful for treatment individualisation and deserves further investigation.

Multivisceral resections for rectal cancer.

BACKGROUND: En bloc resection of adjacent pelvic organ(s) may be needed to achieve clear surgical margins in rectal cancer surgery. An institutional experience is reported with perioperative morbidity and oncological outcomes. METHODS: Patients were identified retrospectively from a prospectively collected institutional database (1992-2010). Outcomes, and clinical and pathological factors were determined from medical records. Estimated overall survival, overall recurrence and local recurrence were compared using the log rank method and Cox regression analysis. RESULTS: Among 1831 patients with rectal cancer, 124 (6·8 per cent) underwent en bloc resection of part or all of an adjacent organ (vagina/uterus/ovary 90, prostate/seminal vesicle 23, bladder/ureter 15, small bowel/appendix 7). Five-year overall survival and local recurrence rates were 53·3 and 18·8 per cent respectively. There was one postoperative death, from multiple organ failure in a patient with liver cirrhosis. Fifty-two patients underwent sphincter-preserving surgery and three (6 per cent) developed an anastomotic leak. On univariable analysis, the only factor associated with local recurrence was completeness of resection (local recurrence rate 15 per cent versus 69 per cent for R0 versus R1 resection; P < 0·001). On multivariable analysis, factors associated with overall survival were sphincter-preserving surgery, absence of metastatic disease and R0 resection. CONCLUSION: Multiple organ resection for locally advanced primary rectal cancer had good oncological outcomes when clear resection margins were achieved.

Dynamic contrast enhanced-MRI for the detection of pathological complete response to neoadjuvant chemotherapy for locally advanced rectal cancer.

OBJECTIVE: To determine the ability of dynamic contrast enhanced (DCE-MRI) to predict pathological complete response (pCR) after preoperative chemotherapy for rectal cancer. METHODS: In a prospective clinical trial, 23/34 enrolled patients underwent pre- and post-treatment DCE-MRI performed at 1.5T. Gadolinium 0.1 mmol/kg was injected at a rate of 2 mL/s. Using a two-compartmental model of vascular space and extravascular extracellular space, K(trans), k(ep), v(e), AUC90, and AUC180 were calculated. Surgical specimens were the gold standard. Baseline, post-treatment and changes in these quantities were compared with clinico-pathological outcomes. For quantitative variable comparison, Spearman's Rank correlation was used. For categorical variable comparison, the Kruskal-Wallis test was used. P ≤ 0.05 was considered significant. RESULTS: Percentage of histological tumour response ranged from 10 to 100%. Six patients showed pCR. Post chemotherapy K(trans) (mean 0.5 min(-1) vs. 0.2 min(-1), P = 0.04) differed significantly between non-pCR and pCR outcomes, respectively and also correlated with percent tumour response and pathological size. Post-treatment residual abnormal soft tissue noted in some cases of pCR prevented an MR impression of complete response based on morphology alone. CONCLUSION: After neoadjuvant chemotherapy in rectal cancer, MR perfusional characteristics have been identified that can aid in the distinction between incomplete response and pCR. KEY POINTS: Dynamic contrast enhanced (DCE) MRI provides perfusion characteristics of tumours. These objective quantitative measures may be more helpful than subjective imaging alone Some parameters differed markedly between completely responding and incompletely responding rectal cancers. Thus DCE-MRI can potentially offer treatment-altering imaging biomarkers.

Accuracy of multidetector computed tomography in identifying poor prognostic factors in colonic cancer.

BACKGROUND: Recent neoadjuvant strategies for high-risk colonic tumours have renewed interest in accurate preoperative staging. The aim of this study was to validate prospectively the accuracy of multidetector computed tomography (MDCT) in stratifying patients into good and poor prognostic groups in a multicentre setting. METHODS: Staging MDCT scans of 84 patients with colonic cancer were reviewed by two independent radiologists and stratified into low-risk (T1/T2 and T3 with extramural tumour depth (EMD) of less than 5 mm) and high-risk (T3 with EMD of at least 5 mm and T4) tumours. Nodal status and extramural venous invasion (EMVI) were also assessed. RESULTS: The accuracy, sensitivity, specificity and positive predictive value of stratification by CT compared with histological examination was 74 (95 per cent confidence interval 64 to 82), 78 (65 to 87), 67 (49 to 81) and 81 (68 to 89) per cent respectively. Accuracy for detecting malignant lymph nodes and EMVI was 58 and 70 per cent respectively. The agreement for predicting prognostic stratification was moderate (kappa = 0.54). CONCLUSION: As the ability of CT to identify node status is poor, the depth of tumour invasion beyond the muscularis propria is the most accurate way to identify patients with a poor prognosis who may be suitable for neoadjuvant treatment.

Risk-reducing surgery in FAP: role for surgeons beyond the incision.

BACKGROUND: Although primary therapy in familial adenomatous polyposis (FAP) is surgical, little is known about patients' surgical decision-making experience. The objective was to explore the decision-making process surrounding risk-reducing surgery in FAP using qualitative methodology. METHODS: In-depth, semi-structured interviews with 14 FAP patients and 11 healthcare providers with experience caring for FAP patients were conducted. Using grounded theory, line-by-line content analysis identified categories from which themes describing patients' experiences emerged; analysis continued until data saturation. RESULTS: Median age at surgery was 23 (7-37) years; at interview 41 (19-74) years. Two patients underwent surgery secondary to cancer, the remainder for risk-reduction. Content experts included colorectal surgeons (3), geneticists (2), gastroenterologists (3), nurses (3).Three themes emerged: Information: Family was the primary information source, and patients' level of information varied. The importance of up-front information was emphasized. Influences on decision-making: Influential factors included family experiences, youth, emotional state, support, and decision-making role. Although patients often sought opinions, most (12/14) wanted an active/shared role in decision-making. Life after surgery: Patients described surgery as the "easy part," emphasizing the need for long-term relationships with care providers. CONCLUSIONS: Decisions surrounding risk-reducing surgery in FAP are unique. A decision support tool may facilitate decision-making, better preparing patients for life after surgery.

A Study on Isolation and Molecular Identification of Bordetella avium from Iranian Commercial and Backyard Broiler Turkeys within 2016-2018.

Bordetellosis or turkey coryza, caused by Bordetella avium, has been an issue for turkey industry since its first description in 1967 when it was reported for the first time. Bordetella avium causes a highly contagious upper respiratory disease in turkeys. Therefore, this study aimed to isolate and characterize this species from commercial and backyard turkeys in Tehran, Isfahan, and Northern provinces of Iran. For the purpose of the study, 625 tracheal swabs were taken from 425 commercial poults and 200 backyard poults aged 2-6 weeks from September 2016 to September 2018. The swabs were immediately plated on MacConkey and blood agar plates and then pooled (5 swabs/pool) in tubes, containing 2 mL distilled water, to perform direct polymerase chain reaction (PCR) for the identification of B. avium. A total of 17 swab pools were found to be positive for B. avium. A subset of seven positive samples were sequenced for the flanking region of piuA gene. The analysis of the sequences indicated that the sequences were 98%, 96%, and 98% similar to B. avium 197N (AM167904.1), 4142 (AY925058.1), and 4156 (AY925068.1) sequences, respectively. To the best of our knowledge, the current study is the first attempt toward the molecular detection and characterization of B. avium in Iran. It is highly recommended to perform further studies to isolate, characterize, and differentiate the regional isolates in order to help the developing turkey industry of Iran meet the increasing demands for protein in the diet of the citizenry.

Incisional hernias after laparoscopic and robotic right colectomy.

PURPOSE: Incisional hernia (IH) is a common complication after colectomy, with impacts on both health care utilization and quality of life. The true incidence of IH after minimally invasive colectomy is not well described. The purpose of this study was to examine IH incidence after minimally invasive right colectomies (RC) and to compare the IH rates after laparoscopic (L-RC) and robotic (R-RC) colectomies. METHODS: This is a retrospective review of patients undergoing minimally invasive RC at a single institution from 2009 to 2014. Only patients undergoing RC for colonic neoplasia were included. Patients with previous colectomy or intraperitoneal chemotherapy were excluded. Three L-RC patients were included for each R-RC patient. The primary outcome was IH rate based on clinical examination or computed tomography (CT). Univariate and multivariate time-to-event analyses were used to assess predictors of IH. RESULTS: 276 patients where included, of which 69 had undergone R-RC and 207 L-RC. Patient and tumor characteristics were similar between the groups, except for higher tumor stage in L-RC patients. Both the median time to diagnosis (9.2 months) and the overall IH rate were similar between the groups (17.4 % for R-RC and 22.2 % for L-RC), as were all other postoperative complications. In multivariable analyses, the only significant predictor of IH was former or current tobacco use (hazard raio 3.0, p = 0.03). CONCLUSIONS: This study suggests that the incidence of IH is high after minimally invasive colectomy and that this rate is equivalent after R-RC and L-RC. Reducing the IH rate represents an important opportunity for improving quality of life and reducing health care utilization after minimally invasive colectomy.

Decision analysis as an aid to determining the management of early low rectal cancer for the individual patient.

PURPOSE: Because there are no data available from randomized controlled trials (RCT), a decision analysis was performed to aid in the decision of which option, a local excision with or without radiotherapy or an abdominal perineal resection (APR), should be offered to medically fit patients with early (suspected T1/T2) low (< 5 cm) rectal cancer. METHODS: All clinically relevant outcomes, including complications of surgery and radiotherapy, cure, salvageability after local recurrence, distant disease, and death, were modeled for both options. The probabilities of complications and outcomes after radiotherapy and/or local excision were derived from weighted averages of results from studies conducted between 1969 and 1997. The probabilities for the APR option were extracted from relevant RCTs. Long- and short-term patient-centered utilities for each complication and outcome were extracted from the literature and from expert opinion. RESULTS: The expected utility of local excision (EU = 0.81) for the base case was higher than the expected utility for APR (EU = 0.78). Although the result was sensitive to all variables, local excision was always favored over APR within the plausible ranges of the variables taken one, two, or three at a time. The model illustrated the tension between the patient's perception of a colostomy and the higher recurrence rates with local excision. CONCLUSION: The results of this decision analysis suggest that local therapy for early low rectal cancer is the preferred method of treatment. However, there must be careful preoperative assessment, patient selection, and consideration of patient concerns. In addition, decision analysis may be useful in providing patient information and assisting in decision making.

Diagnosing insulin resistance in the general population.

OBJECTIVE: Difficulties in measuring insulin sensitivity prevent the identification of insulin-resistant individuals in the general population. Therefore, we compared fasting insulin, homeostasis model assessment (HOMA), insulin-to-glucose ratio, Bennett index, and a score based on weighted combinations of fasting insulin, BMI, and fasting triglycerides with the euglycemic insulin clamp to determine the most appropriate method for assessing insulin resistance in the general population. RESEARCH DESIGN AND METHODS: Family history of diabetes, BMI, blood pressure, waist and hip circumference, fasting lipids, glucose, insulin, liver enzymes, and insulin sensitivity index (ISI) using the euglycemic insulin clamp were obtained for 178 normoglycemic individuals aged 25-68 years. Product-moment correlations were used to examine the association between ISI and various surrogate measurements of insulin sensitivity. Regression models were used to devise weights for each variable and to identify cutoff points for individual components of the score. A bootstrap procedure was used to identify the most useful predictors of ISI. RESULTS: Correlation coefficients between ISI and fasting insulin, HOMA, insulin-to-glucose ratio, and the Bennett index were similar in magnitude. The variables that best predicted insulin sensitivity were fasting insulin and fasting triglycerides. The use of a score based on Mffm/I = exp[2.63 - 0.28ln(insulin) - 0.31ln(TAG)] rather than the use of fasting insulin alone resulted in a higher sensitivity and a maintained specificity when predicting insulin sensitivity. CONCLUSIONS: A weighted combination of two routine laboratory measurements, i.e., fasting insulin and triglycerides, provides a simple means of screening for insulin resistance in the general population.

Immunohistochemistry for hMLH1 and hMSH2: a practical test for DNA mismatch repair-deficient tumors.

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.

Development of a computerized telecommunication system for in-training evaluation of residents in a laparoscopic educational program.

OBJECTIVE: To describe our initial experience with a computerized telecommunication system, termed the interactive voice-response system, to record resident performance of laparoscopic surgery. METHODS: After completing a laparoscopic procedure, the surgeon and resident telephone a toll-free number independently and respond to three prerecorded statements using a Likert scale of 1 to 5. The caller then is asked to describe the resident's response to critical incidents or elements of surprise that arose during the surgery. The ratings and verbal comments are compiled, transcribed, and forwarded to the respective resident. The resident (and program director) can hear the verbal comments by entering a four-digit code. RESULTS: Between May 1, 1995, and May 31, 1996, 430 cases were reported by 11 surgeons and 16 residents using the interactive voice-response system. One hundred ninety-five (45%) procedures were entered by both the resident and surgeon. A survey undertaken during the introductory phase of the project revealed that five of the seven residents exposed to the system found that it provided useful feedback and preferred the system to traditional in-service reporting methods. In addition, five residents thought that the system complemented the personal feedback they received in the operating room. CONCLUSION: The system has been accepted by both residents and surgeons and has addressed the important components of resident in-training evaluation, namely, evaluation on a case-by-case basis, timely feedback, and self-assessment of resident performance.

Is incidental prophylactic oophorectomy an acceptable means to reduce the incidence of ovarian cancer?

BACKGROUND: According to previous reports, the lifetime risk of developing ovarian carcinoma is 1.4%. This figure varies with age from 6.6 per 100,000 among women aged 35 to 39 years up to 55.1 per 100,000 among women aged 75 to 79 years. Prophylactic oophorectomy remains a modality to decrease the incidence of ovarian cancer. What proportion of women diagnosed with an ovarian malignancy had a preceding laparotomy at which time a prophylactic oophorectomy could have been performed? METHODS: We reviewed the new ovarian cancer diagnoses seen in patients between August 1988 and August 1993 at the Ottawa Regional Cancer Foundation. Four hundred and four patients were identified. These patients were analyzed for preceding abdominal surgery, age, time to disease progression, time to death, time to death from other causes, and average follow-up. The previous abdominal surgeries were divided into: (1) major gynecological surgery; and (2) general surgery procedures, which were further divided into laparotomy and pelvic surgery (group A surgeries) and general surgery that included other abdominal surgeries (ie, appendectomy, cholecystectomy) where access to the pelvis could be more difficult (group B surgeries). RESULTS: A total of 270 abdominal surgeries was performed, prior to the diagnosis of ovarian cancer. The group was stratified according to the timing of the surgery (< or =40 years, 41 to 45 years, 46 to 50 years, >50 years). Based on these data, and on the grouping of general gynecologic surgeries plus the general surgical procedures of group A, 10.9% of ovarian cancers would have been prevented if prophylactic oophorectomy had been performed in patients who had surgery over 40 years of age; over 45 years this was 6.7%, over 50 years it was 4%. If one adds all major surgeries, including general surgery groups A and B, the results were 26.9% over 40 years of age, 20% over 45, and 16.6% over 50. CONCLUSION: We found that, depending on the age of the patient, prophylactic oophorectomy results in a 4% to 10.9% reduction in the incidence of ovarian carcinoma. This increases to 16.6% to 26.9% if one considers general surgery procedures in which access could be more difficult. Although we are not advocating the frequent use of this procedure, we recommend that surgeons routinely discuss this option before surgery with their postmenopausal female patients over 49 years of age. Given that the decision for prophylactic oophorectomy is multifaceted, we feel that a risk scoring for ovarian cancer and a discussion of the risk and benefit ratio should be undertaken. The ultimate goal is to heighten patient awareness of the risk factors to ensure that an informed decision is made concerning this consistently lethal disease.

Prevalence of gastrointestinal infection among international travellers returning to Canada.

OBJECTIVE: To describe the prevalence of parasitic and bacterial gastrointestinal infection (excluding enterotoxigenic Escherichia coli) among international travellers attending the International Travel Clinic at The University of Calgary. METHODS: Data were abstracted from the records of the first visit after travel of all persons making a post travel visit between January 1, 1986 and March 31, 1990. RESULTS: Data were available for 886 first visits (840 persons). Stools were submitted by 692 travellers. The frequency of stool submission varied by the duration of travel abroad, and the frequency of diarrhea either during or after the trip was greater among those who had submitted a stool specimen. The prevalence of stools positive for ova, parasites or pathogenic bacteria was 41.2%. When only pathogenic organisms were considered, the prevalence of infection was 19.4%. The most commonly isolated pathogenic parasites were Dientamoeba fragilis, Giardia lamblia, and Entamoeba histolytica. The most commonly isolated bacteria were Campylobacter species and Salmonella species. CONCLUSIONS: Although the prevalence of positive stool screens among returned travellers in this population was high, only about one-fifth of persons tested were positive for pathogens.

Goblet cell carcinoid neoplasm of the appendix: clinical and CT features.

PURPOSE: To describe the clinical and CT imaging features of goblet cell carcinoid (GCC) neoplasm of the appendix. METHODS AND MATERIALS: A computer search of pathology and radiology records over a 19-year period at our two institutions was performed using the search string "goblet". In the patients with appendiceal GCC neoplasms who had abdominopelvic CT, imaging findings were categorized, blinded to gross and surgical description, as: "Appendicitis", "Prominent appendix without peri-appendiceal infiltration", "Mass" or "Normal appendix". The CT appearance was correlated with an accepted pathological classification of: low grade GCC, signet ring cell adenocarcinoma ex, and poorly differentiated adenocarcinoma ex GCC group. RESULTS: Twenty-seven patients (age range, 28-80 years; mean age, 52 years; 15 female, 12 male) with pathology-proven appendiceal GCC neoplasm had CT scans that were reviewed. Patients presented with acute appendicitis (n=12), abdominal pain not typical for appendicitis (n=14) and incidental finding (n=1). CT imaging showed 9 Appendicitis, 9 Prominent appendices without peri-appendiceal infiltration, 7 Masses and 2 Normal appendices. Appendicitis (8/9) usually correlated with typical low grade GCC on pathology. In contrast, the majority of Masses and Prominent Appendices without peri-appendiceal infiltration were pathologically confirmed to be signet ring cell adenocarcinoma ex GCC. Poorly differentiated adenocarcinoma ex GCC was seen in only a small minority of patients. Hyperattenuation of the appendiceal neoplasm was seen in a majority of cases. CONCLUSIONS: GCC neoplasm of the appendix should be considered in the differential diagnosis in patients with primary appendiceal malignancy. Our cases demonstrated close correlation between our predefined CT pattern and the pathological classification.

Appearances of colorectal hepatic metastases at diffusion-weighted MRI compared with histopathology: initial observations.

OBJECTIVE: To describe the appearances of colorectal liver metastases on diffusion-weighted MRI (DW-MRI) and to compare these appearances with histopathology. METHODS: 43 patients with colorectal liver metastases were evaluated using breath-hold DW-MRI (b-values 0, 150 and 500 s mm(-2)). The b=500 s mm(-2) DW-MRI were reviewed consensually for lesion size and appearance by two readers. 18/43 patients underwent surgery allowing radiological-pathological comparison. Tissue sections were reviewed by a pathologist, who classified metastases histologically as cellular, fibrotic, necrotic or mixed. The frequency of DW-MRI findings and histological features were compared using the χ(2) test. RESULTS: 84 metastases were found in 43 patients. On b=500 s mm(-2) DW-MRI, metastases showed three high signal intensity patterns: rim (55/84), uniform (23/84) and variegate (6/84). Of the 55 metastases showing rim pattern, 54 were >1 cm in diameter (p<0.01, χ(2) test). 25/84 metastases were surgically resected. Of these, 11/22 metastases >1 cm in diameter showed rim pattern and demonstrated central necrosis at histopathology (p=0.04, χ(2) test). No definite relationship was found between uniform and variegate patterns with histology. CONCLUSION: Rim high signal intensity was the most common appearance of colorectal liver metastases >1 cm diameter on DW-MRI at b-values of 500 s mm(-2), a finding attributable to central necrosis.