Associations of pigmentary and naevus phenotype with melanoma risk in two populations with comparable ancestry but contrasting levels of ambient sun exposure

BACKGROUND

People at high risk of developing melanoma are usually identified by pigmentary and naevus phenotypes.

OBJECTIVE

We examined whether associations of these phenotypes with melanoma risk differed by ambient sun exposure or participant characteristics in two population-based, case-control studies with comparable ancestry but different ambient sun exposure.

METHODS

Data were analysed from 616 cases and 496 controls from the Australian Melanoma Family Study and 2012 cases and 504 controls from the Leeds (UK) case-control study. Questionnaire, interview and dermatological skin examination data were collected using the same measurement protocols. Relative risks were estimated as odds ratios using unconditional logistic regression, adjusted for potential confounders.

RESULTS

Hair and skin colour were the strongest pigmentary phenotype risk factors. All associations of pigmentary phenotype with melanoma risk were similar across countries. The median number of clinically assessed naevi was approximately three times higher in Australia than Leeds, but the relative risks for melanoma associated with each additional common or dysplastic naevus were higher for Leeds than Australia, especially for naevi on the upper and lower limbs. Higher naevus counts on the head and neck were associated with a stronger relative risk for melanoma for women than men. The two countries had similar relative risks for melanoma based on self-reported naevus density categories, but personal perceptions of naevus number differed by country. There was no consistent evidence of interactions between phenotypes on risk.

CONCLUSIONS

Classifying people at high risk of melanoma based on their number of naevi should ideally take into account their country of residence, type of counts (clinical or self-reported), body site on which the naevus counts are measured and sex. The presence of naevi may be a stronger indicator of a genetic predisposition in the UK than in Australia based on less opportunity for sun exposure to influence naevus development.

Spatial-temporal Variations of Bovine Tuberculosis Incidence in France between 1965 and 2000

We analysed the spatiotemporal variations of bovine tuberculosis (bTB) incidence between 1965 and 2000 in France at the department level (95 areas). Using a Bayesian space-time model, we studied the association between the evolution of bTB incidence and changes of cattle population structure and of herd management practices. Several spatiotemporal hierarchical Bayesian models were compared, and the deviance information criterion was used to select the best of them. Southern France remained a high-risk area over the analysed period, whereas central and western regions were low-risk areas. Besides the frequency of tuberculin skin testing (fixed according to bTB incidence in the preceding years), four factors were associated with an increased risk of bTB: the average herd density and size, the percentage of dairy cows in the cattle population, and the percentage of permanent grassland in cultivated surfaces area. These four factors are linked to the progressive professionalization and specialization of cattle farming, with the disappearance of family farms and of the intensification of breeding systems (especially in dairy farms after the application of the milk quota system in the 1980s). Both trends probably played a significant role in reducing the risk of bTB in France between 1965 and 2000, besides mandatory detection and control procedures.

MR Imaging of sclerosing cholangitis

MRCP is a non-invasive cholangiographic technique used in detection and characterization of bile ducts abnormalities. MRCP features of primary sclerosing cholangitis are randomly distributed annular strictures alternating with slightly dilated bile ducts. Secondary sclerosing processes including ascending, ischemic, caustic, AIDS-related, eosinophilic and autoimmune cholangitis can mimic PSC at MRCP.

[Diffusion-weighted MR imaging of liver pathology: principles and clinical applications]

Due to ongoing technological advances, the range of clinical applications for diffusion-weighted MR imaging has expanded to now include abdominal pathology. Current applications for liver pathology include two main directions. First, oncologic imaging with detection, characterization and follow-up of lesions. Second, evaluation of diffuse liver diseases, including hepatic fibrosis. The diagnostic impact and role of diffusion-weighted MR imaging remain under investigation, but appear promising. Because of its short acquisition time, sensitivity, and additional information it provides, diffusion-weighted MR imaging should be included in routine liver imaging protocols.

[Pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography]

PURPOSE

The quality of magnetic resonance cholangiopancreatography (MRCP) images is frequently degraded by high signal from the gastrointestinal tract on heavily T2W images. The purpose of this study is to evaluate pineapple juice (PJ) as an oral negative contrast agent in MRCP.

MATERIALS AND METHODS

Results from MRCP in 50 patients with PJ and 50 patients with paramagnetic contrast (ferumoxsil-Lumirem) were compared. Reviewers were blinded to the type of contrast agent. Exam quality was recorded with regards to signal suppression in the stomach, duodenum and proximal small bowel and with regards to pancreatic duct and biliary ducts visualization. In vitro, the signal characteristics of several commercially available brands of PJ were assessed using T1W, T2W and MRCP sequences. Signal intensity was correlated with the manganese concentration measured using atomic absorption spectrometry. Finally, the reviewers compared the taste of PJ and ferumoxsil.

RESULTS

On MRCP sequences, results were similar with regards to signal suppression in the stomach, duodenum and proximal small bowel with PJ and ferumoxsil. Visualization of the pancreatic duct, intrahgepatic bile ducts and CBD was similar with PJ and ferumoxsil. The signal intensity of commercially available brands of PJ on T2W and MRCP sequences correlated well with the measured manganese concentration on spectroscopy. Variations in manganese concentration were observed, with values ranging from 3.65 to 27.24 mg/L. The reviewers noted that PJ tasted "good" or "very good" and that ferumoxsil tasted "bad" or "very bad".

CONCLUSION

Ingestion of PJ provides effective signal suppression in the GI tract on MRCP, similar to paramagnetic contrast agents. Because manganese concentration is highly variable in commercially available PJ brands, a brand with high manganese concentration should be selected.

[External phased-array MR imaging preoperative assessment of rectal cancer]

The main problem associated with rectal cancer treatment is tumor recurrence. Randomized controlled studies have shown that adjuvant preoperative radiation therapy is effective for reducing local recurrence. These studies have also demonstrated that there are groups of rectal cancer patients with differing degrees of risk for local recurrence. At one end of the spectrum is the low-risk group: patients with superficial rectal cancer, who can be treated with surgery alone. At the other end is the high-risk group: patients with a close or involved resection margin at total mesorectal excision, the very advanced tumors that require a longer course of chemotherapy and radiation therapy, and extensive surgery. Paramount for this selection and differentiated treatment is a reliable preoperative test that can be used to distinguish these groups of patients. In this review article, we will discuss the role of high-resolution phased array MRI among the other imaging modalities such as endorectal MRI, endorectal US, and CT. We will also discuss and illustrate MR imaging results in terms of T stage, circumferential resection margin, locally advanced rectal cancer, and N stage.

Brain donation for research: strong support in Australia

Permission by families for transplant donation has decreased in Australia. We do know that Australians are interested in donating organs. What has not been explored is how people feel about donating brain tissue for medical research. This study examines the verbal responses of the next of kin, on the day of autopsy of the deceased, to the question of brain donation for medical research. On the day of autopsy a telephone call was made to the next of kin. Families were asked to consider donating the brain tissue of the deceased to medical research. All responses were recorded. Fifty-eight per cent of families contacted by telephone gave permission for the brain donation. The main reasons given for donating the brain to research were wanting to help others, and the family knowing the deceased's wishes. This is an excellent response from families and more encouraging than the literature would predict. Further education and awareness about brain donation is needed and may be achieved effectively by combining donation options with the Australian Organ Donor Register.

[D-Dimer determination combined with clinical probability for the diagnosis of leg venous thrombosis]

OBJECTIVE

To evaluate the results of combination of D-Dimer test and simple clinical model for the diagnosis of deep vein thrombosis (DVT).

MATERIALS AND METHODS

Inclusion: clinical suspicion of DVT. Non inclusion criteria were Clinical model performed by the referring physician included probability varying from high to low. D-Dimer test was performed by five different rapid techniques. Standard of reference was Doppler ultrasonography (DU) performed by a senior radiologist.

RESULTS

Eight hundred and fifty-four DU were performed on a 14 months time period, including 206 suspicion of pulmonary embolism, 109 postoperative time period, 120 non-included or excluded patients, 278 incomplete observations, 141 complete observations. DVT was present in 33 cases and absent in the other 108 cases (prevalence 23%). Sensitivity and negative predictive value of the five tests were between 82 and 97% and 90 et 97%. The most sensitive test had a specificity of 36% and a positive predictive value of 32%. Combination of clinical model and D-Dimer test did not improve the diagnostic accuracy.

CONCLUSION

None of the test evaluated in the present study, even when combined with the clinical model results, did allow the exclusion of DVT.

Merkel cell carcinoma: a rare cause of hypervascular nasal tumor

Cutaneous neuroendocrine carcinoma, first described in 1972, is an aggressive disease usually occurring in sun-exposed skin. Other sites have been described, however; such tumors occasionally occur within the nasal fossa. A high rate of metastasis (>30%) explains the poor prognosis. Descriptions of the imaging features of these tumors, mainly located in cutaneous region, are rare. We therefore present the imaging features of two cases of Merkel cell carcinoma involving the sinonasal region, suggestive of a hypervascular tumor.

[Infectious aneurysms of the cavernous carotid artery]

We describe 3 patients who developed infectious aneurysms of the cavernous carotid artery. The aneurysms were due to sphenoidal sinusitis in two patients and due to endocarditis in one. The acute and septic onset of the cavernous sinus syndrome, suggested thrombophlebitis of the cavernous sinus in all 3 patients. The diagnosis was established by magnetic resonance imaging and magnetic resonance angiography. Therapeutic internal carotid artery occlusion was indicated for a fissuration of their aneurysm manifested (n=3) by an episode of epistaxis (n=2) and blood in sphenoid sinus (depicted by MRI) in one case. We discuss the pathophysiology and management of bacterial aneurysms of the cavernous carotid artery. Close clinical and imaging follow-up should be performed for patients under antibiotherapy. Selective angiography with therapeutic occlusion of the carotid artery is discussed in patients with persistence of symptoms or if clinical findings are suggestive of fissuration or if aneurysmal sac diameter increases on follow-up imaging studies.

Ovarian cancer recurrence: value of MR imaging

PURPOSE

To assess magnetic resonance (MR) imaging in depiction of ovarian tumor recurrence and for identification of patients who may not benefit from surgical reexploration.

MATERIALS AND METHODS

In a prospective study, 34 patients (mean age, 57.07 years) with surgically staged ovarian cancer underwent MR imaging before reexploration. Findings at MR imaging and surgery were correlated. MR imaging tumor depiction was correlated with tumor size, presence of ascites, and CA-125 levels.

RESULTS

Tumor recurrence was identified in 29 patients at surgery. MR imaging depicted tumor in 20 patients. Accuracy for lesions smaller than 2 cm was 35% and increased to 82% for lesions larger than 2 cm (P < .01). MR imaging had low sensitivity for depiction of implants in the peritoneum and mesentery. Ascites improved depiction of smaller lesions (< 2 cm). MR imaging in combination with CA-125 levels improved detection of recurrent disease (CA-125 measurement alone 53% vs CA-125 measurement and MR imaging 75%, P = .048).

CONCLUSION

MR imaging is a useful adjunct to the clinical examination to identify patients with recurrent disease and those in whom reexploration may not be beneficial.

Cervical carcinoma: computed tomography and magnetic resonance imaging for preoperative staging

OBJECTIVE

To assess the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of invasive cervical cancer.

METHODS

Seventy-nine women with untreated cervical cancer underwent pre-treatment MRI (n = 71) and/or CT (n = 37) within 4 weeks of surgical evaluation. Twenty-nine women had both MRI and CT. Images were evaluated for tumor detection, size, stromal invasion, local extension, and nodal metastases.

RESULTS

Tumor size was evaluated accurately by MRI, with a correlation coefficient of 0.93. Magnetic resonance estimates of tumor size were within 0.5 cm of the surgical sample in 64 of 69 women (93%). Magnetic resonance was 88% accurate evaluating the presence of stromal invasion and 78% accurate for depth of stromal invasion. Computed tomography could not evaluate tumor size or stromal invasion because it could not distinguish cancer from the surrounding normal cervical tissue. In evaluating stage of disease, MRI had an accuracy of 90%, compared with 65% for CT (P < .005). Magnetic resonance imaging was more accurate than CT (94 versus 76%, P < .005) in assessing parametrial invasion. Both modalities were comparable in evaluating lymph node metastases (86% each). In determining operative candidates (stage I and minimal IIA), MRI was 94% accurate, compared with 76% for CT (P < .005).

CONCLUSION

Compared with CT, MRI offered significantly improved evaluation of tumor size, stromal invasion, and local and regional extent of disease in pre-treatment imaging for cervical cancer.