Rosalynn M. Nazarian

Incidence of Nephrogenic Systemic Fibrosis after Adoption of Restrictive Gadolinium-based Contrast Agent Guidelines

PURPOSE To retrospectively determine the incidence of nephrogenic systemic fibrosis (NSF) in a large academic medical center after the adoption of restrictive gadolinium-based contrast agent (GBCA) administration guidelines. MATERIALS AND METHODS For this retrospective HIPAA-compliant study, institutional review board approval was obtained and the requirement for informed consent was waived. Restrictive GBCA guidelines were adopted in May 2007. The guidelines (a) require a recent serum creatinine level measurement in any patient who is aged 60 years or older and/or at risk for renal disease, (b) limit the maximal weight-based GBCA dose administered to any patient with an estimated glomerular filtration rate (eGFR) lower than 60 mL/min/m(2) to 20 mL, and (c) prohibit the administration of any GBCA in patients who have an eGFR lower than 30 mL/min/m(2) and/or are undergoing chronic dialysis treatment (except in emergency situations). The electronic medical records were searched for all contrast material-enhanced magnetic resonance (MR) imaging examinations performed during the post-guidelines adoption period between January 2008 and March 2010 and the pre-guidelines adoption and transitional period between January 2002 and December 2007. Separate pathology records were searched for biopsy-confirmed cases of NSF during the same study periods. The incidences of NSF during the pre-guidelines adoption and transitional period and post-guidelines adoption period were compared by using the paired Z test. RESULTS A total of 52,954 contrast-enhanced MR examinations were performed during the post-guidelines adoption period. Of these 52,954 examinations, 46,464 (88%) were performed in adult patients with an eGFR of 60 mL/min/m(2) or higher or presumed normal renal function and 6454 (12%) were performed in patients with an eGFR of 30-59 mL/min/m(2). Thirty-six patients with an eGFR lower than 30 mL/min/m(2) underwent contrast-enhanced MR imaging for emergent indications. Review of the pathology records for January 2008 to September 2010 revealed no new cases of NSF resulting from GBCA exposure. CONCLUSION After restrictive guidelines regarding GBCA administration were instituted, no new cases of NSF were identified among 52,954 contrast-enhanced MR examinations, including those performed in patients with an eGFR lower than 60 mL/min/m(2).

Calciphylaxis: Risk Factors, Diagnosis, and Treatment

Calciphylaxis is a rare but devastating condition that has continued to challenge the medical community since its early descriptions in the scientific literature many decades ago. It is predominantly seen in patients with chronic kidney failure treated with dialysis (uremic calciphylaxis) but is also described in patients with earlier stages of chronic kidney disease and with normal kidney function. In this review, we discuss the available medical literature regarding risk factors, diagnosis, and treatment of both uremic and nonuremic calciphylaxis. High-quality evidence for the evaluation and management of calciphylaxis is lacking at this time due to its rare incidence and poorly understood pathogenesis and the relative paucity of collaborative research efforts. We hereby provide a summary of recommendations developed by a multidisciplinary team for patients with calciphylaxis.

TORC1 Suppression Predicts Responsiveness to RAF and MEK Inhibition in BRAF-Mutant Melanoma

Suppression of TORC1 activity after treatment with RAF or MEK inhibitors predicts drug sensitivity in BRAF-mutant melanoma and can be monitored in patients. Caveat mTOR In recent years, numerous new drugs have been developed to take advantage of specific molecular changes in cancer cells. Unfortunately, tumors are often a step ahead of the scientists, becoming resistant to these targeted drugs just when they seem to be working perfectly. Now, two groups of researchers have developed rational combination treatments that block resistance to targeted cancer drugs by inhibiting mTOR. Elkabets and coauthors were working on breast cancer, where the PIK3CA gene is frequently mutated. Inhibitors of PI3K (the protein product of PIK3CA) are currently in clinical trials, but some of the cancers are resistant to these drugs. The authors have discovered that breast cancers resistant to the PI3K inhibitor BYL719 had persistently active mTOR signaling, both in cultured cell lines and in patient tumors. Adding an mTOR inhibitor to the treatment regimen could reverse the resistance and kill the tumor cells. Corcoran et al. found a similar mTOR-dependent drug resistance mechanism to be active in melanoma as well. BRAF-mutant melanomas, the most common type, are frequently treated with RAF and MEK inhibitors, but only with mixed results, because melanomas quickly develop resistance to these drugs. Now, the authors have shown that drug-resistant melanomas also have persistent activation of mTOR, and adding an mTOR inhibitor to the treatment regimen can block drug resistance and kill the cancer cells. In both studies, the activation of mTOR in drug-resistant tumors has been confirmed in human patients, but the combination treatments have only been tested in cells and in mouse models thus far. Thus, the next critical step would be to confirm that adding mTOR inhibition to treatment regimens for these cancers is effective in the clinical setting as well. Some mTOR inhibitors are already available for use in patients, so hopefully soon mTOR activation will not be something to beware of, but something to monitor and target with specific drugs. RAF and MEK (mitogen-activated or extracellular signal–regulated protein kinase kinase) inhibitors are effective in treating patients with BRAF-mutant melanoma. However, most responses are partial and short-lived, and many patients fail to respond at all. We found that suppression of TORC1 activity in response to RAF or MEK inhibitors, as measured by decreased phosphorylation of ribosomal protein S6 (P-S6), effectively predicted induction of cell death by the inhibitor in BRAF-mutant melanoma cell lines. In resistant melanomas, TORC1 activity was maintained after treatment with RAF or MEK inhibitors, in some cases despite robust suppression of mitogen-activated protein kinase (MAPK) signaling. In in vivo mouse models, suppression of TORC1 after MAPK inhibition was necessary for induction of apoptosis and tumor response. Finally, in paired biopsies obtained from patients with BRAF-mutant melanoma before treatment and after initiation of RAF inhibitor therapy, P-S6 suppression predicted significantly improved progression-free survival. Such a change in P-S6 could be readily monitored in real time by serial fine-needle aspiration biopsies, making quantitation of P-S6 a valuable biomarker to guide treatment in BRAF-mutant melanoma.

Nephrogenic Systemic Fibrosis after Gadopentetate Dimeglumine Exposure: Case Series of 36 Patients

PURPOSE To retrospectively assess the association between gadopentetate dimeglumine exposure at magnetic resonance imaging and the development of nephrogenic systemic fibrosis (NSF). MATERIALS AND METHODS This HIPAA-compliant study had institutional review board approval. Informed consent was waived. A search of medical and pathologic records was performed to identify patients with NSF that was diagnosed between January 1998 and December 2007. Patients with known exposure to gadolinium-based contrast agents other than gadopentetate dimeglumine were excluded. Medical records were then reviewed for gadopentetate dimeglumine exposure, renal status, concomitant diseases, timing of NSF symptom onset, date of NSF diagnosis, and clinical outcome. Skin gadolinium deposition was assessed for those patients with adequate available tissue. Spearman rank correlations were estimated to assess the relationship between the dose of gadopentetate dimeglumine and the time to onset of NSF. RESULTS Thirty-six patients (mean age, 62.6 years; range, 30-83 years) had been exposed to gadopentetate dimeglumine prior to NSF onset. All had stage 5 chronic kidney disease and all but one were undergoing dialysis at the time of exposure. NSF developed within 3 months after the last gadopentetate dimeglumine exposure (range, 1-59 months) in 21 (66%) of 32 patients. The patients had been exposed to median cumulative gadopentetate dimeglumine volumes of 35, 40, 85, and 117.5 mL over the 3, 12, and 24 months and up to 11 years preceding the onset of NSF, respectively. Patients who received higher cumulative and total gadopentetate dimeglumine doses had a higher risk of developing NSF than did those who received lower doses (odds ratio = 1.2). Twenty (56%) of 36 patients died, with a median interval of 18 months between NSF symptom onset and death. CONCLUSION NSF develops in patients with renal impairment after exposure to gadopentetate dimeglumine in a dose- and time-dependent manner. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531082160/-/DC1.

Warfarin-induced skin necrosis

Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy with a high associated morbidity and mortality requiring immediate drug cessation. Cutaneous findings include petechiae that progress to ecchymoses and hemorrhagic bullae. Characteristic dermatopathological findings are diffuse dermal microthrombi with endothelial cell damage and red cell extravasation with progression to full-thickness coagulative necrosis. The lesions of warfarin-induced skin necrosis may be difficult to differentiate from mimickers, but skin biopsy in conjunction with careful consideration of the clinical history, including time of onset, cutaneous distribution of the lesions, and laboratory findings, are essential for prompt diagnosis and patient treatment. Herein, we review the clinical and histologic features helpful for differentiating warfarin-induced skin necrosis and report a case illustrative of the diagnostic difficulty that may at times be encountered in clinical practice.

Melanoma biomarker expression in melanocytic tumor progression: a tissue microarray study.

Background: The elucidation of protein biomarkers that are differentially expressed in human melanocytic tumors during tumor progression may lead to the identification of therapeutic targets and novel diagnostic tests. In a meeting chaired by Dr Mihm, a list of biomarkers of interest in melanoma was compiled. The specialized programs of research excellence (SPORE) in skin cancer developed a melanocytic tumor progression tissue microarray (TMA) to evaluate these candidate biomarkers. In addition to markers reported elsewhere, we evaluated c‐Kit, MITF, MART1, HMB‐45 and bcl‐2.

Increased diagnosis of thin superficial spreading melanomas: A 20-year study

BACKGROUND Diagnostic practice by dermatopathologists evaluating pigmented lesions may have evolved over time. OBJECTIVES We sought to investigate diagnostic drift among a group of dermatopathologists asked to re-evaluate cases initially diagnosed 20 years ago. METHODS Twenty nine cases of dysplastic nevi with severe atypia and 11 cases of thin radial growth-phase melanoma from 1988 through 1990 were retrieved from the pathology files of the Massachusetts General Hospital. All dermatopathologists who had rendered an original diagnosis for any of the 40 slides and the current faculty in the Massachusetts General Hospital Dermatopathology Unit were invited to evaluate the slide set in 2008 through 2009. RESULTS The mean number of melanoma diagnoses by the 9 study participants was 18, an increase from the original 11 melanoma diagnoses. A majority agreed with the original diagnosis of melanoma in all 11 cases. In contrast, a majority of current raters diagnosed melanoma in 4 of the 29 cases originally reported as dysplastic nevus with severe atypia. Interrater agreement over time was excellent (kappa 0.88) and fair (kappa 0.47) for cases originally diagnosed as melanoma and severely atypical dysplastic nevus, respectively. LIMITATIONS The unbalanced composition of the slide set, lack of access to clinical or demographic information, access to only one diagnostic slide, and imposed dichotomous categorization of tumors were limitations. CONCLUSIONS A selected cohort of dermatopathologists demonstrated a general trend toward the reclassification of prior nonmalignant diagnoses of severely atypical dysplastic nevi as malignant but did not tend to revise prior diagnoses of cutaneous melanoma as benign.

Broad range of adverse cutaneous eruptions in patients on TNF-alpha antagonists

Biologic therapies targeting tumor necrosis factor (TNF)‐alpha have become a mainstay in the management of a number of autoimmune diseases. We report a series of adverse skin eruptions in six patients (four females, two males, age: 21–58 years, mean: 39) receiving 4 months to 10 years (mean 3.1 years) of anti‐TNF‐alpha therapies (infliximab, n = 4; adalimumab, n = 1 or etanercept, n = 1). The following drug‐associated diagnoses were made in eight skin biopsies performed at Massachusetts General Hospital between 3/2007 and 10/2010: pustular folliculitis, psoriasis, interface dermatitis, neutrophilic eccrine hidradenitis, Sweets syndrome, lupus, vasculitis and palmoplantar pustulosis. The descriptions of neutrophilic eccrine hidradenitis‐like and Sweets‐like hypersensitivity eruptions induced by anti‐TNF‐alpha therapies are the first such cases described in the literature. Each cutaneous eruption improved or resolved with switching to a different TNF‐alpha inhibitor, discontinuation of the anti‐TNF‐alpha agent, and/or topical or systemic steroids. There was a clear chronologic relationship with, and clinical remission upon withdrawal or steroid suppression of the anti‐TNF‐alpha agents. The mechanism for such diverse cutaneous eruptions among this class of medications remains poorly understood. The cutaneous adverse reaction profile of TNF‐alpha inhibitors is broad and should be considered in the histopathologic differential in this clinical setting.

Quantitative 31P NMR spectroscopy and 1H MRI measurements of bone mineral and matrix density differentiate metabolic bone diseases in rat models

In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX), and partially nephrectomized (NFR) rats was measured by (31)P NMR spectroscopy; bone matrix density was measured by (1)H water- and fat-suppressed projection imaging (WASPI); and the extent of bone mineralization (EBM) was obtained by the ratio of BMD/bone matrix density. The capability of these MR methods to distinguish the bone composition of the CON, OVX, and NFR groups was evaluated against chemical analysis (gravimetry). For cortical bone specimens, BMD of the CON and OVX groups was not significantly different; BMD of the NFR group was 22.1% (by (31)P NMR) and 17.5% (by gravimetry) lower than CON. For trabecular bone specimens, BMD of the OVX group was 40.5% (by (31)P NMR) and 24.6% (by gravimetry) lower than CON; BMD of the NFR group was 26.8% (by (31)P NMR) and 21.5% (by gravimetry) lower than CON. No significant change of cortical bone matrix density between CON and OVX was observed by WASPI or gravimetry; NFR cortical bone matrix density was 10.3% (by WASPI) and 13.9% (by gravimetry) lower than CON. OVX trabecular bone matrix density was 38.0% (by WASPI) and 30.8% (by gravimetry) lower than CON, while no significant change in NFR trabecular bone matrix density was observed by either method. The EBMs of OVX cortical and trabecular specimens were slightly higher than CON but not significantly different from CON. Importantly, EBMs of NFR cortical and trabecular specimens were 12.4% and 26.3% lower than CON by (31)P NMR/WASPI, respectively, and 4.0% and 11.9% lower by gravimetry. Histopathology showed evidence of osteoporosis in the OVX group and severe secondary hyperparathyroidism (renal osteodystrophy) in the NFR group. These results demonstrate that the combined (31)P NMR/WASPI method is capable of discerning the difference in EBM between animals with osteoporosis and those with impaired bone mineralization.

Contrast-enhanced CT with a High-Affinity Cationic Contrast Agent for Imaging ex Vivo Bovine, Intact ex Vivo Rabbit, and in Vivo Rabbit Cartilage

PURPOSE To quantify the affinity of a cationic computed tomography (CT) contrast agent (CA(4+)) and that of an anionic contrast agent (ioxaglate) to glycosaminoglycans (GAGs) in ex vivo cartilage tissue explants and to characterize the in vivo diffusion kinetics of CA(4+) and ioxaglate in a rabbit model. MATERIALS AND METHODS All in vivo procedures were approved by the institutional animal care and use committee. The affinities of ioxaglate and CA(4+) to GAGs in cartilage (six bovine osteochondral plugs) were quantified by means of a modified binding assay using micro-CT after plug equilibration in serial dilutions of each agent. The contrast agents were administered intraarticularly to the knee joints of five New Zealand white rabbits to determine the in vivo diffusion kinetics and cartilage tissue imaging capabilities. Kinetics of diffusion into the femoral groove cartilage and relative contrast agent uptake into bovine plugs were characterized by means of nonlinear mixed-effects models. Diffusion time constants (τ) were compared by using a Student t test. RESULTS The uptake of CA(4+) in cartilage was consistently over 100% of the reservoir concentration, whereas it was only 59% for ioxaglate. In vivo, the contrast material-enhanced cartilage reached a steady CT attenuation for both CA(4+) and ioxaglate, with τ values of 13.8 and 6.5 minutes, respectively (P = .04). The cartilage was easily distinguishable from the surrounding tissues for CA(4+) (12 mg of iodine per milliliter); comparatively, the anionic contrast agent provided less favorable imaging results, even when a higher concentration was used (80 mg of iodine per milliliter). CONCLUSION The affinity of the cationic contrast agent CA(4+) to GAGs enables high-quality imaging and segmentation of ex vivo bovine and rabbit cartilage, as well as in vivo rabbit cartilage. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112246/-/DC1.