Infantile myofibroma: a firm, round plaque in an infant

Infantile myofibroma is a rare fibromatous tumor that is variable in presentation and is frequently mistaken for hemangioma or rhabdomyosarcoma. We describe a 14-month-old boy who presented with multiple, enlarging, firm lesions on the shoulder. Biopsy revealed a proliferation of small spindle cells with myxoid and hyalinized stroma infiltrating into the superficial adipose tissue. We provide a brief review of the clinical presentation, histopathologic features, management, and recent advances in our understanding of this rare condition.

TCC in Transplant Ureter--When and When Not to Preserve the Transplant Kidney

We present four cases of transitional cell carcinoma of the transplant ureter (TCCtu). In three cases, localized tumor resection and a variety of reconstructive techniques were possible. Transplant nephrectomy with cystectomy was performed as a secondary treatment in one locally excised case. Transplant nephroureterectomy was performed as primary treatment in one case. The role of oncogenic viruses and genetic fingerprinting to determine the origin of TCCtu are described. Our cases and a systematic literature review illustrate the surgical, nephrological, and oncological challenges of this uncommon but important condition.

Clinical characteristics and outcomes of HIV-associated immune complex kidney disease

BACKGROUND

The pathogenesis and natural history of HIV-associated immune complex kidney disease (HIVICK) is not well understood. Key questions remain unanswered, including the role of HIV infection and replication in disease development and the efficacy of antiretroviral therapy (ART) in the prevention and treatment of disease.

METHODS

In this multicentre study, we describe the renal pathology of HIVICK and compare the clinical characteristics of patients with HIVICK with those with IgA nephropathy and HIV-associated nephropathy (HIVAN). Poisson regression models were used to identify risk factors for each of these pathologies.

RESULTS

Between 1998 and 2012, 65 patients were diagnosed with HIVICK, 27 with IgA nephropathy and 70 with HIVAN. Black ethnicity and HIV RNA were associated with HIVICK, receipt of ART with IgA nephropathy and black ethnicity and CD4 cell count with HIVAN. HIVICK was associated with lower rates of progression to end-stage kidney disease compared with HIVAN and IgA nephropathy (P < 0.0001). Patients with HIVICK who initiated ART and achieved suppression of HIV RNA experienced improvements in estimated glomerular filtration rate and proteinuria.

CONCLUSIONS

These findings suggest a pathogenic role for HIV replication in the development of HIVICK and that ART may improve kidney function in patients who have detectable HIV RNA at the time of HIVICK diagnosis. Our data also suggest that IgA nephropathy should be viewed as a separate entity and not included in the HIVICK spectrum.

Clinical utility of neuronal cells directly converted from fibroblasts of patients for neuropsychiatric disorders: studies of lysosomal storage diseases and channelopathy

Methodologies for generating functional neuronal cells directly from human fibroblasts [induced neuronal (iN) cells] have been recently developed, but the research so far has only focused on technical refinements or recapitulation of known pathological phenotypes. A critical question is whether this novel technology will contribute to elucidation of novel disease mechanisms or evaluation of therapeutic strategies. Here we have addressed this question by studying Tay-Sachs disease, a representative lysosomal storage disease, and Dravet syndrome, a form of severe myoclonic epilepsy in infancy, using human iN cells with feature of immature postmitotic glutamatergic neuronal cells. In Tay-Sachs disease, we have successfully characterized canonical neuronal pathology, massive accumulation of GM2 ganglioside, and demonstrated the suitability of this novel cell culture for future drug screening. In Dravet syndrome, we have identified a novel functional phenotype that was not suggested by studies of classical mouse models and human autopsied brains. Taken together, the present study demonstrates that human iN cells are useful for translational neuroscience research to explore novel disease mechanisms and evaluate therapeutic compounds. In the future, research using human iN cells with well-characterized genomic landscape can be integrated into multidisciplinary patient-oriented research on neuropsychiatric disorders to address novel disease mechanisms and evaluate therapeutic strategies.

Infantile myofibroma: a firm, round plaque in an infant

Infantile myofibroma is a rare fibromatous tumor that is variable in presentation and is frequently mistaken for hemangioma or rhabdomyosarcoma. We describe a 14-month-old male who presented with multiple, enlarging, firm lesions on the shoulder. Biopsy revealed a proliferation of small spindle cells with myxoid and hyalinized stroma infiltrating into the superficial adipose tissue. We provide a brief review of the clinical presentation, histopathologic features, management and recent advances in our understanding of this rare condition.

Nucleus accumbens injections of the mGluR2/3 agonist LY379268 increase cue-induced sucrose seeking following adult, but not adolescent sucrose self-administration

Adolescence is often portrayed as a period of enhanced sensitivity to reward, with long-lasting neurobiological changes upon reward exposure. However, we previously found that time-dependent increases in cue-induced sucrose seeking were more pronounced in rats trained to self-administer sucrose as adults than as adolescents. In addition, adult, but not adolescent sucrose self-administration led to a decreased α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-Methyl-D-aspartate (AMPA/NMDA) ratio in the nucleus accumbens core, suggesting that long-lasting changes in glutamatergic transmission may affect adult processing of natural rewards. Here we tested whether altering glutamatergic transmission in the nucleus accumbens core via local injection of an mGluR2/3 agonist and antagonist affects cue-induced sucrose seeking following abstinence and whether this is different in the two age groups. Rats began oral sucrose self-administration training (10 days) on postnatal day (P) 35 (adolescents) or P70 (adults). Following 21 days of abstinence, rats received microinjections of the mGluR2/3 agonist LY379268 (0.3 or 1.0 μg/side) or vehicle into the nucleus accumbens core, and 15 min later cue-induced sucrose seeking was assessed. An additional group of rats trained as adults received nucleus accumbens core microinjections of the mGluR2/3 antagonist (RS)-α-Methyl-4-phosphonophenylglycine (MPPG) (0.12 or 0.5 μg/side). Confirming our previous results, adult rats earned more sucrose reinforcers, while sucrose intake per body weight was similar across ages. On abstinence day 22, local injection of the mGluR2/3 agonist LY379268 increased cue-induced sucrose seeking only in adult rats, and had no effect in adolescents. Local injections of the mGluR2/3 antagonist MPPG had no effect on sucrose seeking in adult rats. These data suggest an important developmental difference in the neural substrates of natural reward, specifically a difference in glutamatergic transmission in the accumbens in cue-induced responding for sucrose between adolescent and adult rats.

Abstract 5587: Serial monitoring of EGFR mutations in plasma and evaluation of EGFR mutation status in matched tissue and plasma from NSCLC patients treated with CO-1686

Background: We examined the detection of EGFR mutations in circulating free DNA from plasma and the concordance of EGFR mutation status between matched plasma and tumor tissue in a cohort of newly diagnosed or relapsed patients with advanced NSCLC. CO-1686 is an oral, potent, small-molecule irreversible tyrosine kinase inhibitor that selectively targets mutant forms of EGFR, including T790M, L858R and Del(19), while sparing wild-type EGFR. Promising clinical activity has recently been reported from an on-going Phase I/II trial.

Methods: Matched tumor tissue and blood from 97 evaluable Stage IIIB/IV NSCLC patients, 40 treated with CO-1686, were tested using two allele-specific PCR assays, the cobas® EGFR FFPET and cobas® EGFR blood tests. Each test detects 41 mutations in EGFR, including the T790M resistance mutation, exon 19 deletions and L858R. In a subset of 30 patients, we compared the cobas plasma results to BEAMing, a highly quantitative and sensitive technology based on digital PCR. BEAMing was also used to serially monitor changes of the plasma EGFR mutation burden of several patients in response to CO-1686.

Results: Using tissue as the reference, the positive percent agreement between tissue and plasma was 73% (57/78) for activating mutations and 62% (21/34) for T790M. The cobas® EGFR blood test identified two patients with T790M mutations in plasma that were not detected in the corresponding tumor biopsy_likely because of tumor heterogeneity. The M0/M1a/M1b status was known for 73 EGFR mutation-positive patients. Of the 49 with extrathoracic metastatic disease (M1b), 43 were found to have an activating mutation in plasma (88%). Conversely, only 50% (12/24) of EGFR mutation-positive patients with intrathoracic metastatic disease (M0/M1a) had detectable activating mutations in plasma (p &lt;0.001). Similar results were observed for T790M. For the subset of 30 patients tested by BEAMing at baseline, the overall percent agreement between BEAMing and the cobas® EGFR blood test was 87% (26/30) for T790M and 90% (27/30) for activating mutations. Serial monitoring by BEAMing identified an initial decrease in plasma T790M levels in response to CO-1686 in 13 of 14 patients where clinical activity was observed.

Conclusions: Using the cobas® EGFR blood test, a high proportion of EGFR mutations identified in tissue were also detected in plasma. Mutations were more readily detectable in the plasma of patients with M1b rather than M1a/M0 disease. Serial monitoring identified quantitative changes in EGFR mutation levels over time in patients treated with CO-1686. These findings suggest that the cobas® EGFR blood test and BEAMing can be useful tools for the non-invasive assessment and monitoring of EGFR mutations in the plasma of NSCLC patients.

Citation Format: Rafal Dziadziuszko, Chris Karlovich, Wei Wen, Jong-Mu Sun, Sean Chien, Elaina Mann, Patrick O'Donnell, Philipp Angenendt, Heather Wakelee, Leora Horn, David Spigel, Lecia Sequist, Jean-Charles Soria, Benjamin Solomon, D. Ross Camidge, Jonathan Goldman, Shirish Gadgeel, Mitch Raponi, Andrew Allen, Lin Wu, Keunchil Park. Serial monitoring of EGFR mutations in plasma and evaluation of EGFR mutation status in matched tissue and plasma from NSCLC patients treated with CO-1686. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5587. doi:10.1158/1538-7445.AM2014-5587

Multifocal cutaneous alternariosis in a 70-year-old Kenyan renal transplant patient

Alternaria species are a group of dematiaceous fungi that are ubiquitous in nature and are becoming an increasingly important cause of disease in immunocompromised patients. We present a case of a 70 year old renal transplant recipient with multiple areas of cutaneous Alternaria infections likely introduced during local trauma. Treatment has required a combination of systemic therapy and surgical excision. This case illustrates the importance of recognizing fungal infections with cutaneous manifestations, such as alternariosis, in immunosuppressed patients.

Scalp sarcoidosis: a sign of systemic sarcoidosis

Sarcoidosis is a systemic disease often with cutaneous manifestations. Scarring alopecia of the scalp is a rare form of cutaneous sarcoidosis. Herein, we describe a case of sarcoidosis of the scalp mimicking discoid lupus.

Analytic performance studies and clinical reproducibility of a real-time PCR assay for the detection of epidermal growth factor receptor gene mutations in formalin-fixed paraffin-embedded tissue specimens of non-small cell lung cancer

Background

Epidermal growth factor receptor (EGFR) gene mutations identify patients with non-small cell lung cancer (NSCLC) who have a high likelihood of benefiting from treatment with anti-EGFR tyrosine kinase inhibitors. Sanger sequencing is widely used for mutation detection but can be technically challenging, resulting in longer turn-around-time, with limited sensitivity for low levels of mutations. This manuscript details the technical performance verification studies and external clinical reproducibility studies of the cobas EGFR Mutation Test, a rapid multiplex real-time PCR assay designed to detect 41 mutations in exons 18, 19, 20 and 21.

Methods

The assay’s limit of detection was determined using 25 formalin-fixed paraffin-embedded tissue (FFPET)-derived and plasmid DNA blends. Assay performance for a panel of 201 specimens was compared against Sanger sequencing with resolution of discordant specimens by quantitative massively parallel pyrosequencing (MPP). Internal and external reproducibility was assessed using specimens tested in duplicate by different operators, using different reagent lots, instruments and at different sites. The effects on the performance of the cobas EGFR test of endogenous substances and nine therapeutic drugs were evaluated in ten FFPET specimens. Other tests included an evaluation of the effects of necrosis, micro-organisms and homologous DNA sequences on assay performance, and the inclusivity of the assay for less frequent mutations.

Results

A >95% hit rate was obtained in blends with >5% mutant alleles, as determined by MPP analysis, at a total DNA input of 150 ng. The overall percent agreement between Sanger sequencing and the cobas test was 96.7% (negative percent agreement 97.5%; positive percent agreement 95.8%). Assay repeatability was 98% when tested with two operators, instruments, and reagent lots. In the external reproducibility study, the agreement was > 99% across all sites, all operators and all reagent lots for 11/12 tumors tested. Test performance was not compromised by endogenous substances, therapeutic drugs, necrosis up to 85%, and common micro-organisms. All of the assessed less common mutations except one (exon 19 deletion mutation 2236_2248 > AGAC) were detected at a similar DNA input level as that for the corresponding predominant mutation.

Conclusion

The cobas EGFR Mutation Test is a sensitive, accurate, rapid, and reproducible assay.

A case of Hansen Disease presenting as tinea versicolor

Hansen Disease (leprosy) is an infectious disease that targets macrophages and Schwann cells, caused by the acid fast intracellular organism, Mycobacterium leprae. Clinically, it presents with a spectrum of findings that may include hypopigmented macules, erythematous plaques and nodules, and thickened or tender peripheral nerves. The most feared complication is mutilating damage to facial structures or digits resulting from loss of sensation in affected skin. In non-endemic areas, the diagnosis of leprosy is frequently delayed because it may mimic other more common skin conditions. We present a case of borderline/lepromatous leprosy in an otherwise healthy young Brazilian man that was initially diagnosed as tinea versicolor, but did not respond to appropriate treatment. This case highlights the importance of having a high index of suspicion for leprosy in patients from endemic areas who present with lesions that could be consistent with this disease.

Retrospective EGFR mutation testing of clinical specimens from the EURTAC trial of erlotinib in non-small cell lung cancer (NSCLC) using a novel allele-specific PCR (AS-PCR) assay

10596

Background: Anti-EGFR inhibitors are superior to chemotherapy in first-line therapy of advanced EGFR-mutant NSCLC. The EURTAC trial was a randomized Phase III trial of erlotinib vs. chemotherapy in patients with EGFR-mutant NSCLC. Interim results showed significant improvement in progression-free survival (R. Rosell, ASCO 2011). An accurate rapid in vitro diagnostic for EGFR mutations is needed to select patients for this therapy. Methods: Prospective EGFR mutation testing for the trial was performed on laser-capture microdissected tumor cells using a combination of 3 lab-developed tests (LDTs), including a Length Analysis of Fluorescently-labeled PCR (Genescan) method for exon 19 deletions, a Taqman-based PCR assay for exon 21 mutation with laser-capture macrodissected tumor cells, and secondary Sanger sequencing. A subset of samples from the trial was retrospectively tested with an AS-PCR assay (cobas EGFR mutation test) which detects L858R and > 29 exon 19 deletions. The test provides automated results within 8 h; the DNA required can be isolated from one 5-micron tissue section. Four methods were compared: AS-PCR assay, LDT, direct Sanger sequencing and massively parallel sequencing (MPS; 454, Branford, CT). Results: LDT results were obtained for 1044 screened patients. Residual tumor blocks were available for 487 patients (47%), including 303 wild-type, 172 mutant (135 enrolled on the trial) and 12 inconclusive cases by the LDT. Comparison of AS-PCR and LDT results showed a positive percent agreement (PPA) – 93.7% (CI 88.8%, 96.5%), and negative percent agreement (NPA) – 97.5% (94.9%, 98.8%). Comparison of AS-PCR and Sanger results showed a PPA of 96.6% (91.7%, 98.7%) but an NPA of 88.3% (84.1%, 91.5%). Among 34 AS-PCR+/Sanger- case, MPS confirmed the presence of exon 19 deletions in 25 cases and L858R mutations in 7. Direct comparison of AS-PCR and MPS results showed a PPA of 93.1% (88.1%, 96.1%) and NPA of 97.7% (95.0%, 98.9%). Clinical outcomes for cases with mutations detected by the AS-PCR test will be presented. Conclusions: The AS-PCR assay was highly concordant with the LDT and MPS, and more sensitive than Sanger sequencing.

Abstract 1707: A real-time PCR assay for detecting EGFR mutations in formalin-fixed paraffin-embedded tissue (FFPET) specimens of non-small cell lung cancer (NSCLC)

EGFR mutations identify patients with NSCLC who have a high likelihood of benefiting from first-line treatment with anti-EGFR tyrosine kinase inhibitors. Sanger sequencing is widely used for mutation detection but can be time-consuming, and has limited sensitivity for low levels of mutations. We describe the analytic performance of the cobas EGFR Mutation Test, a multiplex, 3-reaction real-time PCR assay designed to detect 41 mutations in exons 18, 19, 20 and 21. The mutations detected and the mutation report calls are listed below: The amount of DNA required for the assay (150 ng) can typically be isolated from a single 5-micron FFPET section, and the test can be performed in &lt; 8 hours. Analytic sensitivity was assessed using DNA blends from NSCLC FFPET tumor sections. A &gt;95% hit rate was obtained in blends with &gt;5% mutant alleles for L858R and exon 19 deletions as determined by 454 sequencing (quantitative massively parallel pyrosequencing) at a total DNA input of 150ng, or 50 ng per PCR amplification. The cobas test was compared to 2x bidirectional Sanger sequencing using a set of 152 NSCLC FFPET specimens. The overall percent agreement (OPA) between the 2 methods was 96.7% (negative agreement - NPA 97.5%; positive agreement - PPA 95.8%). Specimens with discordant cobas EGFR Test and Sanger results were analyzed by 454 and a revised agreement analysis was performed based on the composite results of the 3 assays. The revised OPA was 98.7% (NPA 98.8%; PPA 98.6%). The call repeatability of a panel of NSCLC FFPET specimens was 98% when tested with two operators, instruments, and reagent lots. Necrotic tissue, hemoglobin, triglycerides, and common respiratory organisms did not interfere with the assay. The test showed no cross reactivity with the corresponding exon sequences from the HER2, HER3, and HER4 genes. These analytic studies demonstrate that the cobas EGFR Mutation Test is a sensitive, accurate and reproducible assay.

The importance of auricular prostheses for speech recognition

OBJECTIVES

To examine the effects of an auricular prosthesis on sound levels at the entrance of the ear canal by measuring the auricular prosthesis transfer function (APTF) and to determine the effect of the prosthesis on speech recognition in noisy hearing conditions.

METHODS

Eight prostheses were used to measure the APTF. A microphone at the entrance of the ear canal measured sound pressure levels with the prosthesis present or absent while the head was rotated 360 degrees at 30 degrees increments. The Hearing in Noise Test was modified by the APTF to simulate the absence of an auricular prosthesis. Speech recognition was measured by testing 11 subjects with the unmodified Hearing in Noise Test and the modified Hearing in Noise Test.

RESULTS

The APTF changed with the head's position relative to the speaker. The mean (SD) maximal gain provided by an auricular prosthesis was 8.1 (2.7) dB at 4.6 (1.0) kHz and 9.7 (1.7) dB at 11.5 (0.9) kHz at 0 degrees rotation. During speech testing, the auricular prosthesis improved the mean (SD) signal to noise ratio by 1.7 (1.7) dB at 0 degrees (P< .001), 0.9 (2.2) dB at 90 degrees (P=.04), and 0.5 (2.3) dB at 180 degrees (P=.52).

CONCLUSIONS

The acoustic gain provided by an auricular prosthesis increases speech recognition in noisy environments. Auricular prostheses not only restore aesthetics but also improve hearing.

Clinical characterization of cardiovascular abnormalities associated with feline mucopolysaccharidosis I and VI

OBJECTIVE

The purpose of this study was to define the cardiovascular abnormalities present in young and adult cats affected with the lysosomal storage diseases mucopolysaccharidosis (MPS) I and MPS VI.

METHOD

Eighteen cats affected with MPS I and 10 cats affected with MPS VI were evaluated by physical examination, electrocardiography and echocardiography. Electrocardiography (ECG) was performed on all MPS I and 9 of the MPS VI cats. Twelve unaffected cats underwent complete examinations for comparison purposes.

RESULTS

No cardiovascular abnormalities were noted on physical examination. Measured ECG intervals were normal in affected cats; however, sinus arrhythmia was noted more frequently than in the unaffected cats. Significant echocardiographic abnormalities included aortic valve thickening, regurgitation and aortic root dilation. Significant mitral valve thickening was also noted. The severity of changes increased in older affected cats.

CONCLUSION

As affected animals increased in age, more cardiac abnormalities were found with increasing severity. Significant lesions included the mitral and aortic valves and ascending aorta, but myocardial changes were not recognized. MPS I and MPS VI cats have similar cardiovascular findings to those seen in children and constitute important models for testing new MPS therapies.

Tuberculosis complicating tertiary hyperparathyroidism in a patient with end-stage renal disease: a case report

A 36-year-old Nigerian woman on thrice-weekly dialysis presented with symptoms and signs of hypercalcaemia. Laboratory findings were consistent with tertiary hyperparathyroidism. Parathyroid hormone levels remained elevated and she underwent elective parathyroidectomy. Intra-operatively all 4 parathyroid glands and local lymph nodes showed necrotising granulomas with occasional acid-fast bacilli, pathognomonic of tuberculosis (TB). Post-operatively she completed a full course of anti-TB therapy and at 9 months she experienced complete resolution in her plasma biochemistry and was essentially symptom-free. This is a rare yet fascinating cause of hypercalcaemia in a dialysis patient and is the first recorded case of tubercular involvement of parathyroid tissue in a case of tertiary hyperparathyroidism. This report demonstrates the coexistence of 2 diseases that simultaneously worsened hypercalcaemia and thus emphasises the importance of the differential diagnosis and of careful histological examination post-operation.

Apparent diffusion coefficient reveals gray and white matter disease, and T2 mapping detects white matter disease in the brain in feline alpha-mannosidosis

BACKGROUND AND PURPOSE

Methods to locate and identify brain pathology are critical for monitoring disease progression and for evaluating the efficacy of therapeutic intervention. The purpose of this study was to detect cell swelling, abnormal myelin, and astrogliosis in the feline model of the lysosomal storage disease alpha-mannosidosis (AMD) by using diffusion and T2 mapping.

MATERIALS AND METHODS

Average apparent diffusion coefficient (ADC(av)) and T2 were measured by imaging the brains of five 16-week-old cats with feline AMD on a 4.7T magnet. ADC(av) and T2 data from affected cats were compared with data from age-matched normal cats. Brains were collected from both affected and normal cats following imaging, and histology was compared with quantitative imaging data.

RESULTS

Gray matter from AMD cats demonstrated a 13%-15% decrease in ADC(av) compared with that in normal cats. White matter from AMD cats exhibited an 11%-16% decrease in ADC(av) and a 5%-12% increase in T2 values compared with those in normal control cats. Histologic evidence of neuronal and glial swelling, abnormal myelin, and astrogliosis was consistent with changes in ADC(av) and T2.

CONCLUSION

ADC(av) and T2 data can be used to quantify differences in the gray and white matter in the feline AMD brain and may serve as surrogate markers of neuronal swelling, abnormal myelin, and astrogliosis associated with this disease. These studies may be helpful in assessing the efficacy of experimental therapies for central nervous system disease associated with lysosomal storage diseases.

Renal failure with granulomatous interstitial nephritis and diffuse leukemic renal infiltration in chronic lymphocytic leukemia

Renal dysfunction is uncommon in patients with leukemic infiltration of the kidney due to Chronic Lymphocytic Leukanemia (CLL). Granulomatous interstitial nephritis (GIN) is also rare, but a characteristic hallmark of certain diseases such as sarcoidosis and tuberculosis. GIN has been associated with medications, infections, inflammation, Wegener's granulomatosis, and jejuno-ileal bypass. GIN combined with leukemic infiltration by CLL is very uncommon. We present a 72-year-old male with Binet stage A CLL who developed progressive renal failure over a period of four years requiring maintenance dialysis. During the course of his illness, he underwent renal biopsies at different time intervals, revealing varying degrees of involvement by GIN together with leukemic infiltration.

An unusual presentation of muscular sarcoidosis

Sarcoidosis is a noncaseating granulomatous disease that involves multiple organs, most commonly the lungs, lymph nodes, skin, and eyes, but may be clinically evident in any organ system. Symptomatic muscular sarcoidosis is very rare and has been reported in only 1.4% of known sarcoidosis cases, while skeletal involvement has been reported in 1-13%. Different types of muscular and osseous sarcoidosis have been described in the literature. We present a case of muscular sarcoidosis, which is unique in its clinical presentation and imaging findings. The presence of the marked periosteal reaction, which has never been described with muscular sarcoidosis, also makes this case unique.

Cholinergic neurons of the adult rat striatum are immunoreactive for glutamatergic N-methyl-d-aspartate 2D but not N-methyl-d-aspartate 2C receptor subunits

Cholinergic neurons of the striatum play a crucial role in controlling output from this region. Their firing is under the control of a relatively limited glutamatergic input, deriving principally from the thalamus. Glutamate transmission is effected via three major subtypes of receptors, including those with affinity for N-methyl-d-aspartate (NMDA) and the properties of individual receptors reflect their precise subunit composition. We examined the distribution of NMDA2C and NMDA2D subunits in the rat striatum using immunocytochemistry and show that a population of large neurons is strongly immunoreactive for NMDA2D subunits. From their morphology and ultrastructure, these neurons were presumed to be cholinergic and this was confirmed with double immunofluorescence. We also show that NMDA2C is present in a small number of septal and olfactory cortical neurons but absent from the striatum. Receptors that include NMDA2D subunits are relatively insensitive to magnesium ion block making neurons more likely to fire at more negative membrane potentials. Their localization to cholinergic neurons may enable very precise regulation of firing of these neurons by relatively small glutamatergic inputs.

MRI appearances of common benign soft-tissue tumours

Benign soft-tissue tumours are many times more common than their malignant counterparts, and magnetic resonance imaging (MRI) is the technique of choice for imaging the lesions. This review illustrates the MRI appearances of the most common benign soft-tissue tumours, based on consecutive referrals to our institution. The imaging signs that are useful for diagnosis are described.

A sensitive mutation-specific screening technique for GNAS1 mutations in cases of fibrous dysplasia: the first report of a codon 227 mutation in bone

AIMS

To report on the mutation-specific restriction enzyme digest (MSRED) method using paraffin-embedded tissue as a means of detecting GNAS1 mutations in fibrous dysplasia (FD), and to determine if any of the reported GNAS1 mutations in endocrine neoplasms, not previously documented in FD, can be found in FD.

METHODS AND RESULTS

Sixty-seven cases of extragnathic FD were analysed as two groups, 1997-2002 and 2003-06, chosen because tissue fixation and decalcification methods were more accurately recorded in the latter. MSRED revealed that between 2003 and 2006, 93% of 28 'in house' extragnathic cases harboured a GNAS1 mutation, compared with 75% of 32 cases before 2003. Fixation times of no more than 48 h and decalcification in ethylenediamine tetraacetic acid gave the best results. Of the 56 mutations detected (five gnathic, 51 extragnathic), 32 (57%) were R201H, 21 (38%) were R201C and three (5%) were Q227L. Two Q227L extragnathic cases had unusual clinical/radiological findings. No mutations were detected in osteofibrous dysplasia.

CONCLUSION

Detection of GNAS1 mutations by MSRED is a valuable adjunct to the histopathological diagnosis of FD. This is the first report of a Q227L mutation in FD, although it has been previously documented in pituitary adenoma.

Femoroacetabular impingement: bone marrow oedema associated with fibrocystic change of the femoral head and neck junction

AIM

To describe the association of bone marrow oedema adjacent to areas of fibrocystic change at the femoral head and neck junction in patients with femoroacetabular impingement.

MATERIALS AND METHODS

The clinical and imaging findings in six patients with bone marrow oedema adjacent to an area of fibrocystic change at the femoral head and neck junction are presented. There were five males and one female (age range 19-42 years, mean age 34.5 years). Three patients were referred with a clinical suspicion of femoroacetabular impingement, two with suspected osteoid osteoma and one with a clinical diagnosis of sciatica. The volume of bone marrow oedema (grade 1: 0-25%, grade 2: 26-50%, grade 3: 51-75% and grade 4: 76-100% of the femoral neck width), presence of labral and articular cartilage abnormality, joint effusion, and femoral head and neck morphology were recorded.

RESULTS

Magnetic resonance imaging (MRI) identified fibrocystic change in the anterolateral aspect of the femoral head and neck junction in all cases (mean size 9 mm, range 5-14 mm, three multilocular and three unilocular cysts). The volume of oedema was variable (one grade 1, two grade 2, one grade 3 and two grade 4). All patients had abnormality of the anterosuperior labrum with five patients demonstrating chondral loss. An abnormal femoral head and neck junction was identified in five patients.

CONCLUSION

The radiological finding of fibrocystic change at the anterosuperior femoral neck with or without bone marrow oedema should prompt the search for femoroacetabular impingement. Bone marrow oedema may rarely be identified adjacent to these areas of cystic change and should be considered in the differential diagnosis of bone marrow oedema in the femoral neck.

Non-neoplastic conditions presenting as soft-tissue tumours

Review of referrals to our unit over the last 7 years showed that of approximately 750 cases referred as soft-tissue tumours, 132 were subsequently diagnosed as non-neoplastic lesions. The imaging characteristics of these lesions are presented to differentiate them from neoplasms. The most common diagnoses were myositis ossificans, ganglion cyst, abscess/infection, bursitis and synovitis. The imaging features of other rarer conditions will also be discussed.

Imaging of the posterolateral corner of the knee

The structures of the posterolateral corner of the knee are increasingly recognized as fulfilling an important role in maintaining knee stability. The posterolateral aspect of the knee is stabilized by a complex anatomy of osseous, myotendinous and ligamentous structures. Unrecognized injuries to this part of the knee are a cause of failure of cruciate ligament reconstruction. This review focuses on the anatomy and common injury patterns involving the posterolateral corner of the knee, with emphasis on magnetic resonance imaging.

Synovial sarcoma with radiological appearances of primitive neuroectodermal tumour/Ewing sarcoma: differentiation by molecular genetic studies

Synovial sarcoma (SS) arises in soft tissues but may invade adjacent bone. We describe a case of SS presenting as aggressive lysis of the proximal ulna, the imaging of which suggested a primary bone lesion. Needle biopsy showed a "small round blue cell tumour", and a primitive neuroectodermal tumour (PNET)/Ewing sarcoma was suggested on the basis of the imaging appearances. The definitive diagnosis of synovial sarcoma was made following molecular genetic studies, which demonstrated a fusion product incorporating the genes SYT and SSX1. The importance of correct diagnosis to guide appropriate management, and, therefore, the necessity for molecular genetic studies, is discussed.

Compartmentalization of class II antigen presentation: contribution of cytoplasmic and endosomal processing

During antigen processing, peptides are generated and displayed in the context of major histocompatibility complex (MHC) class II molecules on the surface of antigen-presenting cells (APCs) to modulate immune responses to foreign antigens and guide self-tolerance. Exogenous and cytoplasmic antigens are processed by distinct routes within APCs to yield class II ligands. Exogenous antigens are internalized, processed, and bound to class II molecules within endosomal and lysosomal compartments of APCs. Studies reviewed here demonstrate the importance of reduction in regulating exogenous antigen presentation. The differential expression of a gamma-interferon-inducible lysosomal thiol reductase in professional APCs and melanomas is discussed in the context of tumor immune evasion. Cytoplasmic autoantigens, by contrast, are degraded by the proteasome and other enzymes in the cytosol, with the resulting peptides translocating to endosomal and lysosomal compartments for intersection with class II molecules. Processing and editing of these antigenic peptides within endosomes and lysosomes may be critical in regulating their display via class II proteins. Multiple pathways may regulate the transit of cytosolic peptides to class II molecules. The role of lysosome-associated membrane protein-2a and heat-shock cognate protein 70 in promoting cytoplasmic peptide presentation by MHC class II molecules is discussed.

Evaluation of patellar tracking in symptomatic and asymptomatic individuals by magnetic resonance imaging

OBJECTIVE

To determine the patterns of patellar motion in subjects without knee symptoms using dynamic magnetic resonance imaging (MRI).

DESIGN

Patellar tracking MR examinations were performed on 50 asymptomatic volunteers. The presence and degree of lateral subluxation and tilt of the patella was assessed independently by three radiologists, and discrepancies resolved by consensus. Using the same criteria, the tracking pattern in 50 consecutive patients, recently referred for imaging assessment of anterior knee pain, was studied.

PATIENTS

Fifty volunteers (22 male, mean age 37 years) and 50 unmatched patients (15 male, mean age 25.5 years) were examined.

RESULTS AND CONCLUSIONS

Forty-one per cent of a total of 97 knees in the volunteer group showed evidence of lateral subluxation, which was either minimal (grade 1, 32%) or minor (grade 2, 9%). No volunteer demonstrated major (grade 3) subluxation; lateral tilt without translation of the patella was also seen (2%). In the patient group, higher grades of lateral subluxation were more common. Minimal (grade 1) lateralization is a common movement pattern of the patella on knee extension, and should be regarded as normal.

Does body-coil magnetic-resonance imaging have a role in the preoperative staging of patients with clinically localized prostate cancer?

OBJECTIVE

To investigate the accuracy and use of body-coil magnetic resonance imaging (MRI) in the local staging of prostate cancer before radical prostatectomy (RP).

PATIENTS AND METHODS

Fifty-six patients undergoing RP were staged before surgery using body-coil MRI; none was denied surgery on the basis of their scan results. All scans were reported before RP by one of three consultant radiologists and afterward by a colleague with a special interest in prostate MRI, unaware of the patients' clinical details.

RESULTS

The overall sensitivity of MRI at detecting extracapsular extension was 50% on general reporting and 72% when reported by the specialist radiologist; the respective specificities were 84% and 86%. Of the 55 patients included in the study, 18 (33%) had extracapsular disease on histological analysis. MRI was most accurate in the 17 patients at high-risk (prostate-specific antigen, PSA, >10 ng/mL and Gleason score >or= 8) and eight at intermediate risk (PSA < 10 ng/mL and Gleason score 7). In the former group with specialist analysis, the sensitivity was 100%, although this decreased to 67% with general reporting. Both gave a specificity of 82%. Intermediate risk disease gave a sensitivity and specificity of 75%, irrespective of reporting method. The ability of MRI to detect extraprostatic tumour in the 30 low-risk patients (PSA < 10 ng/mL and Gleason score 2-6) was poor; the sensitivity was 25% with general and 50% on specialist review, although both methods gave a specificity of >90%.

CONCLUSION

Body-coil MRI is sensitive and specific for identifying extracapsular extension of prostate cancer in patients with high- or intermediate-risk disease. Patients at low risk frequently have microscopic extension which is not detected. Opinion from a radiologist with a special interest in prostate MRI can increase the reporting accuracy even when unaware of the patients' clinical details.

The prevalence and diagnostic significance of fluid-fluid levels in focal lesions of bone

OBJECTIVE

To determine the prevalence and diagnostic significance of fluid-fluid levels (FFLs) in focal bone lesions.

DESIGN AND PATIENTS

Clinical and radiological details of 738 consecutive patients referred with focal lesions of bone and who had undergone MRI were reviewed. FFLs were identified in 83 (11.2%). The proportion of the lesion occupied by FFLs was estimated, based on imaging in all available planes, as <1/3, 1/3-2/3, >2/3 but not the entire lesion, and complete. The degree of FFL change in each lesion was correlated with the final diagnosis, which was either histological (n=80) or clinicoradiological (n=3). There were 31 female and 52 male patients, mean age 25.5 years (range 5-83 years).

RESULTS

Histology revealed 46 benign, 32 malignant and 2 non-neoplastic lesions. A clinicoradiological diagnosis was made in the 3 lesions without histology: 2 were benign (simple bone cyst and intraosseous lipoma) and 1 malignant (a metastasis). Malignant neoplasms commonly showed FFLs which occupied <1/3 of the entire lesion (n=22/32, 68.8%), and 50% of all the lesions in this group were conventional intramedullary osteosarcomas (n=16). With increasing FFL change, malignancy became less frequent: with >2/3 (but incomplete) FFL change, 81% (n=13/16) of tumours were benign. If the entire tumour showed FFL change, the histology was benign in 100% (n=11).

CONCLUSIONS

The extent of FFLs within a focal bone lesion appears to be inversely related to the degree of malignancy. If at least 2/3 of the lesion shows FFL change, 89% of diagnoses are benign.