BRAFV600E mutation in papillary thyroid microcarcinoma: a genotype-phenotype correlation.

BRAF(V600E) mutation has emerged as a marker of aggressive behavior in papillary thyroid carcinoma but its significance in microcarcinoma is not entirely clear. One-hundred and twenty-nine papillary thyroid microcarcinomas were tested for BRAF(V600E) mutation by single-strand conformation polymorphism, and their clinicopathologic features (age, sex, tumor size, multifocality, nodal metastases, histologic subtype, tumor cell morphology, architecture, tumor-associated stromal reaction, tumor interface to non-neoplastic thyroid (well circumscribed vs infiltrative), extrathyroidal extension, lymphovascular invasion, intratumoral multinucleated giant cells, and adjacent non-neoplastic thyroid pathology) were examined. Compared with tumors without the mutation (39/129, 30%), the mutated microcarcinomas (90/129, 70%) showed significantly higher prevalence of infiltrative tumor borders (78/90 vs 23/39, P=0.001), tumor-associated stromal desmoplasia/fibrosis and/or sclerosis (80/90 vs 25/39, P=0.002), classic nuclear features of papillary thyroid carcinoma (90/90 vs 35/39, P=0.008) and cystic change (43/90 vs 11/39, P=0.05). BRAF(V600E) mutation was more frequent in classic (75%), tall cell (91%), and other variants (>70%) than in follicular variant (21%) of papillary thyroid microcarcinoma. Tumors without the mutation were significantly more likely to be solid, well circumscribed, and lacked desmoplasia/fibrosis or sclerosis. However, on multivariate analysis, only the follicular variant of papillary microcarcinoma was significantly associated with the absence of mutation (odds ratio (95% confidence interval): 0.09 (0.01-0.54)). Lymph node metastases (n=24) were more frequent in microcarcinomas with mutation than without (21/24 vs 3/24, P=0.02). All patients with lateral cervical node metastasis (n=9), and all but one tumor with extrathyroidal extension (n=17/18) showed BRAF(V600E) mutation. No significant differences were noted in age, sex, tumor size, multifocality, lymphovascular invasion, psammoma bodies, stromal calcification, intratumoral multinucleated osteoclastic-type giant cells, and lymphocytic infiltration between the two groups of tumors. BRAF(V600E) mutation is an early event in thyroid carcinogenesis, and is associated with distinctive morphology and aggressive features even in papillary thyroid microcarcinomas.

Papillary thyroid carcinomas with and without BRAF V600E mutations are morphologically distinct.

AIMS: The BRAF V600E mutation resulting in the production of an abnormal BRAF protein has emerged as the most frequent genetic alteration in papillary thyroid carcinomas (PTCs). This study was aimed at identifying distinctive features in tumours with and without the mutation. METHODS AND RESULTS: Thirty-four mutation-positive and 22 mutation-negative tumours were identified by single-strand conformation polymorphism of the amplified BRAF V600E region in the tumour DNA. Mutation-positive tumours were more common in patients older than 45 years (24/33, P = 0.05), in classic (23/30, P = 0.01), tall cell (4/5) and oncocytic/Warthin-like (2/2) variants of PTC, and in subcapsular sclerosing microcarcinomas (4/4). In contrast, all 12 follicular variants (P < 0.0001) and two diffuse sclerosing variants were negative for the mutation. Mutation-positive tumours displayed infiltrative growth (32/34, P = 0.02), stromal fibrosis (33/34, P < 0.001), psammoma bodies (17/34, P = 0.05), plump eosinophilic tumour cells (22/34, P = 0.01), and classic fully developed nuclear features of PTC (33/34, P = 0.0001). Encapsulation was significantly associated with mutation-negative tumours (15/22, P = 0.02). CONCLUSIONS: BRAF V600E mutation-positive and negative PTCs are morphologically different. Recognition of their morphology may help in the selection of appropriate tumours for genetic testing.

Cauda Equina Syndrome in Neurosarcoidosis.

Neurosarcoidosis (NS) is a mimicker of many infectious, neoplastic, and inflammatory diseases. It most commonly involves the cranial nerves followed by meninges, ventricles, hypothalamic-pituitary axis, spinal cord, and brainstem/cerebellum. While NS myelopathy has been increasingly recognized, pathophysiological/prognostic and management principles in NS-mediated cauda equina (CE) and conus medullaris (CM) syndromes, which constitute a small and rare minority of this subset, remain elusive. We present the case of a 49 -year-old Hispanic man who developed a peripheral facial palsy and primary hypogonadism within a span of 12 months and eventually got diagnosed with NS after he presented with CE syndrome. We also performed an extensive literature review, with a discussion on the underlying pathophysiology and current management recommendations for NS-mediated CE/CM syndrome. CE/CM syndromes in a middle-aged man should prompt the consideration of NS as a possible differential diagnosis. While steroid responsive, the majority of NS-CE/CM patients are left with residual neurodeficits with quick relapses when steroids are tapered, making the case for early institution of immunosuppressive therapies.

Evolving antiepileptic drug treatment in juvenile myoclonic epilepsy.

BACKGROUND: In the face of availability of newer antiepileptic drugs (AEDs) such as lamotrigine and topiramate, there is need to reassess the role of older AEDs in the treatment of juvenile myoclonic epilepsy (JME). OBJECTIVES: To explore whether lamotrigine and topiramate monotherapy or polytherapy can be effective options in the treatment of JME, and to determine whether older AEDs, such as phenytoin and carbamazepine, have a role in the treatment of JME. DESIGN: A retrospective cohort study. SETTING: A large academic teaching hospital. PATIENTS: Seventy-two consecutive JME patients treated with valproic acid, lamotrigine, topiramate, phenytoin, or carbamazepine between April 1, 1991, and March 31, 2001. METHODS: We compared the efficacy of valproic acid, lamotrigine, and topiramate monotherapy or polytherapy in the control of different seizure types of JME, and compared their efficacy and tolerability with the efficacy and tolerability of phenytoin and carbamazepine. RESULTS: Seizure outcome did not differ when patients receiving valproic acid monotherapy (n = 36) were compared with those receiving lamotrigine monotherapy (n = 14), and when patients receiving valproic acid polytherapy (n = 22) were compared with those receiving lamotrigine polytherapy (n = 21) or topiramate polytherapy (n = 15) (P>.05 for all). The combined data of myoclonic seizure control by all 3 AEDs were poorer when compared with the combined data of generalized tonic-clonic seizure control by all 3 AEDs (P =.03), but not when compared with the combined data of absence seizure control by all 3 AEDs (P =.43). Valproic acid, lamotrigine, and topiramate, when compared with phenytoin or carbamazepine, demonstrated significantly better control of myoclonic seizures (P<.01 for all), but not of generalized tonic-clonic seizures (P>.11 for all). CONCLUSIONS: Lamotrigine and topiramate are effective alternative options to valproic acid in the treatment of JME. Lamotrigine is an effective option as monotherapy and polytherapy. Topiramate is an effective option as polytherapy, but more data are needed to determine if it is an effective option as monotherapy. More effective therapy is needed to improve myoclonic seizure control. Older AEDs, such as phenytoin and carbamazepine, may not be indicated in JME patients.

Extent of ictal origin in mesial temporal sclerosis patients monitored with subdural intracranial electrodes predicts outcome.

In patients with mesiotemporal sclerosis, posterior hippocampal involvement at the ictal onset is not associated with an excellent outcome. A study confirmed that ictal onset in the posterior parahippocampal gyrus is associated with a less favorable outcome compared with ictal onset in the anterior parahippocampal gyrus in patients with mesiobasal temporal lobe epilepsy who are undergoing foramen ovale recording. The authors hypothesized that involvement of the two medial contact points of posterior basal temporal subdural (SD) strip at the ictal onset, representing ictal onset in the posterior parahippocampal gyrus, may also adversely influence the surgical outcome. With this objective, the authors assessed the incidence of posterior basal temporal SD strip (the two medial contact points) involvement at the ictal onset in patients with mesiotemporal sclerosis and determined whether presence of this finding influenced surgical outcome. Thirty-six patients with mesiotemporal sclerosis underwent a single SD grid (lateral frontotemporal) and strips (three basal temporal and one orbitosubfrontal) monitoring. Based on the earliest involvement of basal temporal strips (the two medial contact points) during the seizure, patients were classified into (1) anterior and/or middle basal temporal, or (2) posterior basal temporal (with or without involvement of anterior and/or middle basal temporal) ictal onset groups. A temporal lobectomy with adequate resection of the ictal onset zone was performed in all patients. Surgical outcome was based on Engel's classification. Six of 36 (17%) patients were classified into the posterior basal temporal ictal onset group. Only two patients from the posterior basal temporal ictal onset group experienced a good outcome compared with 26 of 30 patients from anterior and/or middle basal temporal ictal onset group (P = 0.01). In patients with mesiotemporal sclerosis who were monitored with SD electrodes, involvement of the two medial contact points of posterior basal temporal strip at the ictal onset (representing ictal onset in the posterior parahippocampal gyrus) occurred in 17% of the patients. These patients might not experience an excellent surgical outcome despite including the ictal onset zone in resection. These findings may be useful in presurgical counseling of patients with mesiotemporal sclerosis who undergo intracranial SD monitoring.

Morphology predicts BRAF (V6°°E) mutation in papillary thyroid carcinoma: an interobserver reproducibility study.

Papillary thyroid carcinomas (PTC) with BRAF (V600E) mutation are morphologically distinctive. They are typically classic or tall cell variants, show infiltrative borders, and are associated with desmoplasia/fibrosis, psammoma bodies, and well-developed nuclear features of papillary carcinoma. We hypothesize that morphologic features of PTC can help in the prediction of BRAF (V600E) mutation, and we evaluate the accuracy and the interobserver reproducibility of such prediction. Hematoxylin and eosin-stained sections from 50 PTCs comprising of 26 mutation-positive and 24 mutation-negative tumors were examined. BRAF (V600E) mutation was predicted correctly in 42/50 tumors (accuracy, 84 %) with 96 % sensitivity, 71 % specificity, and 78 % positive and 94 % negative predictive values (NPV). Subtle nuclear features of PTC (n = 10) had the highest (100 %) negative predictive value followed by well-circumscribed non-infiltrative tumor borders (17/22 mutation-negative tumors, 95 % NPV). The positive predictive value of infiltrative tumor borders (21/28 [75 %] mutation-positive), desmoplasia/fibrosis (23/31 [74 %] mutation-positive), and psammoma bodies (13/20 [65 %] mutation-positive) increased to 100 % when all three features were present (n = 8/8 mutation-positive). To assess interobserver reproducibility, two pathologists blinded to the mutational status evaluated 30 PTCs (15 mutation-positive and 15 mutation-negative) after self-training on 10 PTCs with known BRAF (V600E) mutational status (five mutation-positive and five mutation-negative). The prediction of the mutation was achieved with substantial agreement (κ value, 0.79) and accuracy (25/30, 83 %). This study demonstrates that BRAF (V600E) mutation in papillary thyroid carcinoma can be predicted on morphology with accuracy and with substantial interobserver agreement.

Tall cell variant of papillary thyroid microcarcinoma: clinicopathologic features with BRAF(V600E) mutational analysis.

BACKGROUND: The tall cell variant of papillary thyroid carcinoma is an aggressive subtype that generally presents as a large tumor in the advanced stage; however, little is known about the tall cell variant of microcarcinoma (tumors measuring <1 cm). In this study, we compare the tall cell variant of microcarcinoma (microTCV) with classic papillary microcarcinomas to examine the hypothesis that, despite the small size, the microTCV may be more aggressive than the classic papillary microcarcinoma. METHODS: We identified 27 microTCV patients and compared their clinicopathologic features and BRAF(V600E) mutational status with classic papillary microcarcinomas matched by age and size. The patients with microTCV included 22 women and 5 men aged 33 to 74 years (median age, 56 years). All patients underwent total thyroidectomy; 20 patients had lymph node dissection. RESULTS: Tumor size in microTCV patients ranged from 2 mm to 10 mm (median, 7 mm). Extrathyroidal extension and lymphovascular invasion were seen in 9 (33%) and 4 (15%) tumors, respectively. Thirteen patients (48%) harbored multifocal papillary carcinomas. Metastasis to central compartment lymph nodes was seen in 8 patients and to lateral cervical nodes in 3 patients. Nine of the 25 patients (36%) presented at an advanced stage (stage III/IVA). The BRAF(V600E) mutation was detected in 25 of 27 tumors (92.6%). In contrast, age- and size-matched classic papillary microcarcinomas (n=26) showed no extrathyroidal extension (p=0.002), lymphovascular invasion in 1, central compartment lymph node metastasis in 2, lateral cervical node metastasis in 1, multifocal tumors in 10 (38.5%), the BRAF(V600E) mutation in 20 (76.9%), and it infrequently presented in stage III/IVA (7.7%, p=0.02). CONCLUSIONS: The microTCV form is associated with aggressive features at presentation, and it should be differentiated from other papillary thyroid microcarcinomas.

Phenobarbital and MK-801, but not phenytoin, improve the long-term outcome of status epilepticus.

To examine the effect of therapy on status epilepticus (SE) acutely and on long-term outcome, we compared three drugs with three different mechanisms. Phenobarbital, MK-801, and phenytoin were administered at 1, 2, and 4 hours after initiation of limbic status epilepticus by "continuous" hippocampal stimulation in rats. We evaluated the effects of these drugs on the course of SE and the subsequent development of chronic epilepsy. Phenobarbital and MK-801 were superior to phenytoin in suppressing SE and in preventing chronic epilepsy. There was no benefit if treatment was given 2 hours after the initiation of SE. Phenobarbital was most effective in suppressing electrographic seizure activity, but MK-801 had a slightly wider window for the prevention of chronic epilepsy. Early treatment, rather than electrographic suppression of SE, correlated with prevention of chronic epilepsy. This study shows that the drugs administered, which have different mechanisms of action, have clear differences in altering the outcomes. The findings suggest that studies of SE treatment should examine the effect of therapy on SE itself, as well as the long-term benefits of each treatment. The use of N-methyl-D-aspartate receptor antagonists should be considered early in the treatment of SE.

Self-report of cognitive abilities in temporal lobe epilepsy: cognitive, psychosocial, and emotional factors.

Self-report of cognitive functioning using the Multiple Abilities Self-Report Questionnaire (MASQ) was examined in 57 left (LTLE) and 36 right (RTLE) temporal lobe epilepsy patients. The MASQ is a 38-item self-report measure assessing five domains of self-perceived cognitive functioning: Language, Visual-Perceptual Abilities, Verbal Memory, Visual-Spatial Memory, and Attention/Concentration. Overall, LTLE patients self-reported more cognitive difficulties across all domains. Language was the only domain to emerge as a robust indicator of seizure lateralization (LTLE patients reporting more problems). Neuropsychological test performance did not emerge as a significant predictor for any domain, whereas measures of psychosocial and emotional functioning accounted for a significant but modest amount of variance in all of them. The results suggest caution in using such self-report measures as an ecological extension of objective testing, but suggest a role in assessing self-appraisal of deficits.