Somatic mutational profiling and clinical impact of driver genes in Latin-Iberian medulloblastomas: Towards precision medicine.

Medulloblastoma (MB) is the most prevalent malignant brain tumor in children, known for its heterogeneity and treatment-associated toxicity, and there is a critical need for new therapeutic targets. We analyzed the somatic mutation profile of 15 driver genes in 69 Latin-Iberian molecularly characterized medulloblastomas using the Illumina TruSight Tumor 15 panel. We classified the variants based on their clinical impact and oncogenicity. Among the patients, 66.7% were MBSHH, 13.0% MBWNT, 7.3% MBGrp3, and 13.0% MBGrp4. Among the 63 variants found, 54% were classified as Tier I/II and 31.7% as oncogenic/likely oncogenic. We observed 33.3% of cases harboring at least one mutation. TP53 (23.2%, 16/69) was the most mutated gene, followed by PIK3CA (5.8%, 4/69), KIT (4.3%, 3/69), PDGFRA (2.9%, 2/69), EGFR (1.4%, 1/69), ERBB2 (1.4%, 1/69), and NRAS (1.4%, 1/69). Approximately 41% of MBSHH tumors exhibited mutations, TP53 (32.6%) being the most frequently mutated gene. Tier I/II and oncogenic/likely oncogenic TP53 variants were associated with relapse, progression, and lower survival rates. Potentially actionable variants in the PIK3CA and KIT genes were identified. Latin-Iberian medulloblastomas, particularly the MBSHH, exhibit higher mutation frequencies than other populations. We corroborate the TP53 mutation status as an important prognostic factor, while PIK3CA and KIT are potential therapeutic targets.

Single nCounter assay for prediction of MYCN amplification and molecular classification of medulloblastomas: a multicentric study.

PURPOSE: Medulloblastoma is the most frequent pediatric malignant brain tumor, and is divided into four main subgroups: WNT, SHH, group 3, and group 4. MYCN amplification is an important medulloblastoma prognostic biomarker. We aimed to molecular classify and predict MYCN amplification in a single assay. METHODS: It was included 209 medulloblastomas from 205 patients (Brazil, Argentina, and Portugal), divided into training (n = 50) and validation (n = 159) sets. A nCounter assay was carried out using a custom panel for molecular classification, with additional genes, including MYCN. nSolver 4.0 software and the R environment were used for profiling and MYCN mRNA analysis. MYCN amplification by FISH was performed in 64 cases. RESULTS: The 205 medulloblastomas were classified in SHH (44.9%), WNT (15.6%), group 3 (18.1%) and group 4 (21.4%). In the training set, MYCN amplification was detected in three SHH medulloblastomas by FISH, which showed significantly higher MYCN mRNA counts than non-FISH amplified cases, and a cutoff for MYCN amplification was established ([Formula: see text] + 4σ = 11,124.3). Applying this threshold value in the validation set, we identified MYCN mRNA counts above the cutoff in three cases, which were FISH validated. CONCLUSION: We successfully stratified medulloblastoma molecular subgroups and predicted MYCN amplification using a single nCounter assay without the requirement of additional biological tissue, costs, or bench time.

[IgG4 related disease presenting as panhypopituitarism and perimacular scotoma]. / Panhipopituitarismo y escotoma perimacular como presentación de enfermedad relacionada a IgG4.

IgG4-related disease (IgG4-RD) is a recently described systemic entity of unknown origin. It predominantly affects older men and has distinctive histopathologic features as storiform fibrosis, obliterative phlebitis, dense lymphoplasmacytic infiltrate with immunostaining for IgG4, and it may be associated with elevated serum levels of IgG4. Although any organ can be affected, pituitary gland is rarely involved. We describe the case of a 36-year-old man who presented with headaches, impaired vision, panhypopituitarism with diabetes insipidus and an infiltrative lesion mainly of infundibulum and pituitary. We arrived at diagnosis of IgG4-RD by pituitary biopsy. A successful response to treatment with immunosuppressive doses of corticosteroids was achieved.

[Timely diagnosis of disseminated paracoccidioidomycosis in an immunocompetent adult]. / Diagnóstico oportuno de paracoccidioidomicosis diseminada en un adulto inmunocompetente.

Paracoccidioidomycosis is endemic in subtropical rainforests of Latin America. Acute/subacute presentations involve an aggressive dissemination throughout the lymphatic system, while chronic forms (more frequent) arise as differential diagnosis for other conditions involving lung, oropharynx, skin, and eventually the brain. We present the case of a man referred for evaluation and treatment of a possible lung tumor with brain metastasis. The finding of multibudded yeasts and the microbiological isolation of a dimorphic fungus identified as Paracoccidioides sp. from a brain biopsy prompted a cardinal change in prognosis and treatment. This case alerts on the importance of considering systemic fungal diseases as differential diagnosis of compatible clinical presentations in patients who had lived in, or visited, endemic areas.

ANCA-associated pauci-immune glomerulonephritis: always pauci-immune?

OBJECTIVES: Anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (GN) is considered "pauci-immune" with absent or mild glomerular tuft staining for immunoglobulin (Ig) and/or complement. However, it is not unusual to see some immune deposits (ID) within glomeruli on immunofluorescence (IF). We determined to evaluate the prevalence and clinical significance of immune deposits in ANCA-associated GN. METHODS: We included all patients with ANCA associated vasculitis with renal biopsies between January 2002 and May 2014: granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis and renal limited vasculitis. Patients were divided into Group A: biopsy without ID (≤2+ intensity of immunostaining) and Group B: biopsy with ID (>2+ intensity of immunostaining). Serum creatinine, estimated glomerular filtration rate (eGFR) at time of the biopsy, amount of proteinuria and hematuria, requirement of dialysis and extra renal involvement were recorded. RESULTS: Fifty-three patients (75.4% females) were included. Mean age at biopsy was 66.3 years. Typical pauci-immune GN was found in 39 patients (73.5%, group A). In 14 patients (26.4%, group B) examination revealed substantial deposition of Ig or complement in the mesangium and/or along the glomerular capillary wall. The only difference comparing both groups was significantly higher proteinuria in group B (mean 1.6/24 h (SD: 10.7) vs. 0.8/24 h (SD: 7.6), p=0.0036). CONCLUSIONS: In ANCA GN at least a quarter of patients were not "pauci-immune" (26.4%). In this subgroup, immune deposits were only associated with a significantly higher proteinuria. Further basic and clinical research is needed to elucidate the significance of immune deposition in ANCA GN.

Low-impedance Baseline Values Predict Severe Esophagitis.

OBJECTIVES: The aim of the study was to determine whether esophageal baseline impedance (BI) values in children could be predictive of esophagitis. MATERIALS AND METHODS: Multichannel intraluminal impedance (MII) tracings of children 3 to 17 years of age suspected of having gastroesophageal reflux and esophagitis, who had also undergone upper endoscopy with multiple esophageal biopsies, were reviewed. Patients with eosinophilic esophagitis were excluded. Esophagitis was assessed by macroscopic and microscopic parameters. Esophageal histology was reported by 2 blinded independent pathologists unaware of the MII results. Mean BI was automatically calculated in the different MII channels (ch) by the specific software without removing any episode of increased/decreased BI. BI results were plotted against macroscopic and histological scores for each channel. RESULTS: Tracings of 87 children, 53 boys, were evaluated. Mean age was 7.4 years: 45 had histologic esophagitis, 8 macroscopic. Histologic mild esophagitis (grade 1) was observed in 30, and 15 had moderate to severe esophagitis (grade 2-3). Ten had grade 3 esophagitis. Eight had macroscopic esophagitis as well. RESULTS: in channel 6 of the MII, all 10 patients with grade 3 esophagitis and the 8 with macroscopic esophagitis had a BI <900 Ω/s (positive predictive value 100% and negative predictive value 100%), whereas none of those having a biopsy score of 0 to 2 or no endoscopic evidence of esophagitis had a mean BI below 2000 Ω/s. CONCLUSIONS: The evaluation of the BI measured in channel 6 gave us 100% prediction of grade 3 and macroscopic esophagitis. BI on channel 6 may be useful to predict severe esophageal mucosa inflammation and could potentially be used for follow-up evaluation, rather than repeating an upper endoscopy. In addition, it would seem that grade 3 esophagitis even in the absence of macroscopic esophagitis affects the integrity of the esophageal epithelium.

[Pachymeningitis associated with IgG4 disease]. / Paquimeningitis asociada a enfermedad por IgG4.

Hypertrophic pachymeningitis is an infrequent disorder. It can be idiopathic or secondary to infectious, autoimmune or neoplastic disease. The recently described 〈IgG4-related disease〉 could be the origin of many cases considered cryptogenic. We present the case of a 60-year-old man, with a history of headache and episcleritis in both eyes, with partial response to corticoid therapy. The brain MR study with gadolinium showed enhancement and thickening of the dura mater, extending from lateral wall of left temporal and occipital lobes to ipsilateral tentorium. Meningeal biopsy showed fibrosis and lymphoplasmacytic infiltrate, with more than 10 IgG4+ plasma cells per high power field. After treatment with rituximab there was clinical improvement accompanied by the virtual disappearance of the alterations detected in neuroimaging. Hypertrophic pachymeningitis as a manifestation of IgG4-related disease can be based on MRI findings if plasma IgG4 are elevated.

Multidisciplinary approach to anaplastic and metastatic meningioma: A case report and review of the literature.

Background: Meningiomas are slow-growing neoplasms, accounting for 20% of all primary intracranial neoplasms and 25% of all intraspinal tumors. Atypical and anaplastic meningiomas are infrequent, representing fewer than 5% of all meningiomas. Unusually, they can show aggressive behavior, and extracranial metastases are extremely rare, representing approximately 0.1% of all reported cases. Case Description: Fifty-six-year-old male patient diagnosed with atypical basal frontal meningioma with multiple resections, both endoscopic endonasal and transcranial. After hypofractionated radiosurgery, the patient showed new tumor recurrence associated to right cervical level II ganglionic metastasis. We opted for complete resection of the meningioma and reconstruction with anterior rectus abdominis muscle flap, as well as selective cervical ganglionectomy. Anatomical pathology showed neoplastic proliferation of meningothelial cells in syncytial cytoplasm, oval or spherical nuclei with slight anisocariosis and hyperchromasia, and intranuclear vacuoles, all compatible with anaplastic meningioma. Conclusion: Due to a lack of consensus on how to treat a metastatic malignant meningioma, this pathology requires a multidisciplinary approach, and treatment needs to be adapted to each particular case. Complete resection of the lesion is the primary goal, and this requires complex procedures involving endocranial as well as extracranial surgeries, which result in composite defects difficult to resolve. Microvascular free flaps are considered the gold standard in reconstructions of large skull base defects, with high success rates and few complications.

Primary Central Nervous System Vasculitis Following Alemtuzumab Treatment for Multiple Sclerosis: A Case Report and Literature Review.

INTRODUCTION: Cerebral vasculitides are often devastating conditions that require immediate diagnosis and treatment. CASE REPORT: We report a pathologically proven clinical case of primary central nervous system vasculitis in a 50-year-old man with a diagnosis of relapsing-remitting multiple sclerosis after alemtuzumab therapy, which required additional immunosuppression to control this life-threatening condition. CONCLUSION: In patients presenting subacute neurological deterioration after alemtuzumab therapy, primary central nervous system vasculitis should be considered as a differential diagnosis among other autoimmune conditions.

High frequency of WNT-activated medulloblastomas with CTNNB1 wild type suggests a higher proportion of hereditary cases in a Latin-Iberian population.

Purpose: Medulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%-90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics. Methods: A total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively. Results: WNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants. Conclusion: We observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.

Gender differences in macroprolactinomas: study of clinical features, outcome of patients and ki-67 expression in tumor tissue.

Prolactinomas in men are usually macroprolactinomas and other investigators have attributed bigger size of tumors in men to delay in diagnosis. A retrospective study of 71 macroadenomas (42 men) was carried out. Parameters studied were age, signs and symptoms at presentation, time of onset of symptoms, basal prolactin, estradiol, and total testosterone levels, tumor size and Ki 67 expression in tumor tissue. Male patients were older. Visual defects were significantly more prevalent in men. Hardy 4 stage tumors were found only in men. We found no significant correlation between tumor size and the patients age nor between tumor size and the onset of symptoms. Whereas basal E2 levels (21.2+/-12.9 vs. 33.3+/-43.3 pg/ml, p=n.s.) were very similar in male and female patients, testosterone levels were significantly higher in men (0.6+/-0.5 vs. 1.8+/-1.2 ng/ml, p=0.02). The rate of cell proliferation represented by Ki 67 was significantly higher in tumors in men (3.5+/-1.2 vs. 1.5+/-0.5%, p=0.0001). This is the first study focused in macroprolactinomas that shows that they are clinically and biologically more aggressive in men. Hypogonadism in men could appear later in the progression of prolactinomas and this might explain why men were older at the time of diagnosis. Furthermore, testosterone could be a source for E2 in situ aromatization giving male tumors an advantage in cell proliferation.

Restricted diffusion in a ring-enhancing mucoid metastasis with histological confirmation: case report.

We present a case of restricted diffusion in a ring-enhancing cerebellar metastasis in a 58-year-old man. Diffusion imaging showed restriction with low apparent diffusion coefficient values within the cavity. Diagnosis of abscess was suggested based on radiological findings. A suspicious lung nodule was found in the systemic evaluation, and histological examination of the brain lesion confirmed metastatic adenocarcinoma with mucoid content confirmed by further specific pathological tests. We discuss the reason of diffusion findings and the importance of the correct interpretation of this technique in a clinical situation. Our case confirms previous hypothesis about restricted diffusion related to mucoid content in metastasis.

Identification of a somatic mutation in the RHEB gene through high depth and ultra-high depth next generation sequencing in a patient with Hemimegalencephaly and drug resistant Epilepsy.

Malformations of cortical development are a frequent cause of drug-resistant Epilepsy and developmental delay. Hemimegalencephaly is a Malformation of cortical development characterized by enlargement of all or a part of one cerebral hemisphere. Germline and somatic mutation in genes belonging to the Mammalian Target of Rapamycin (mTOR) pathway has been identified in patients suffering from epilepsy secondary to Hemimegalencephaly and focal cortical dysplasia. We present here a patient suffering from severe neonatal Epilepsy since 3 h of life secondary to Hemimegalencephaly, requiring an anatomic hemispherectomy surgical procedure for seizure control, where by means of next-generation sequencing at an ultra-high depth coverage, we were able to identify a novel somatic mutation in the RHEB gene (NM_005614: c.119A > T: p. Glu40Val). The histopathological diagnosis was Cortical Dysplasia type IIB determined by the presence of dysmorphic neurons of variable size with nuclear alteration and balloon cells in the context of Hemimegalencephaly, which are similar to that have been demonstrated in hyperactivating RHEB models. This is the first report of a somatic mutation in RHEB gene in a patient suffering from Epilepsy secondary to Hemimegalencephaly. It highlights different current topics in the fields of genetics of Malformations of cortical development: a-somatic mosaicism is not uncommon in these neurodevelopmental disorders; b-the molecular diagnostic approach should involve the use of state-of-the-art methods and the sampling of different tissues; c-new findings might facilitate therapeutics discoveries while providing an improved understanding of normal brain development.

Factors related to surgical complications and their impact on the functional status in 236 open surgeries for malignant tumors in a Latino-American hospital.

BACKGROUND: There are not many studies that address the selection of patients harboring malignant brain tumors for open surgery. It is necessary, especially in developing countries, to establish the standards because of their impact not only on the efficacy but also on the cost-effectiveness of surgery. With the concern to add information that may help in future studies about the decision making, we proposed to analyze factors associated with surgical complications and evaluate their influence on the functional status at 30 days after surgery. METHODS: A consecutive series of 236 surgeries performed between June 1999 and June 2005 were retrospectively analyzed (168 gliomas, 65 metastases, 3 others). Variables evaluated were age, sex, pre- and postoperative KPS, ASA status, anatomic localization, extent of tumor resection, tumor histology, and number of surgeries. RESULTS: The incidence of complicated craniotomies was 15.68% and mortality was 2.97%. Postoperatively, 92% of the patients improved or maintained the functional status, whereas 8% worsened. In multivariate analysis, only preoperative KPS (P = .009), ASA status (P = .02), and histology type (P = .03) showed significant association with postoperative complications. CONCLUSIONS: We found that the neurologic and clinical preoperative condition and grade III gliomas were factors related to postoperative complications, whereas age, extent of resection, and number of surgeries were not risk factors. We believe that these conclusions provide an additional benchmark for future multicentric studies that focus on the selection criteria for resection of malignant brain tumors.

Immune-mediated rippling muscle disease and myasthenia gravis.

Cases of acquired rippling muscle disease in association with myasthenia gravis have been reported. We present three patients with iRMD (immune-mediated rippling muscle disease) and AChR-antibody positive myasthenia gravis. None of them had thymus pathology. They presented exercise-induced muscle rippling combined with generalized myasthenia gravis. One of them had muscle biopsy showing a myopathic pattern and a patchy immunostaining with caveolin antibodies. They were successfully treated steroids and azathioprine. The immune nature of this association is supported by the response to immunotherapies and the positivity of AChR-antibodies.

[Tubulointerstitial nephritis associated with parvovirus beta19 infection]. / Nefritis tubulo intersticial asociada a parvovirus B19.

A previously healthy 9 year old girl developed nephrotic syndrome with hypertension, microhematuria and normal renal function. The patient evolved as steroid resistant nephrotic syndrome whose initial renal biopsy was consistent with diffuse proliferative mesangial glomerulonephritis with focal segmental glomerulosclerosis. At the time of cyclophosphamide and prednisone treatment, she developed a prolonged febrile syndrome. She also had severe anemia following an aplastic crisis induced by human parvovirus B19 infection and acute renal failure secondary to a severe tubulointersticial disease. Bone marrow and renal tissue, tested by polimerase chain reaction were positive for parvovirus, while the patient's blood was negative. The renal involvement did not improve requiring chronic dialysis support. We believe that the initial glomerular disease could have been due to a parvovirus infection followed by un unexpected acute tubular interstitial nephritis, rapidly progressing to chronic renal disease. This case represents, to our knowledge, the first time that a direct relationship between parvovirus infection and acute tubulointerstitial disease has been demonstrated.

Temozolomide Therapy for Aggressive Pituitary Tumors: Results in a Small Series of Patients from Argentina.

We evaluated results of temozolomide (TMZ) therapy in six patients, aged 34-78 years, presenting aggressive pituitary tumors. In all the patients tested O(6)-methylguanine-DNA methyltransferase (MGMT) immunoexpression in surgical specimens was absent. Patients received temozolomide 140-320 mg/day for 5 days monthly for at least 3 months. In two patients minimum time for evaluation could not be reached because of death in a 76-year-old man with a malignant prolactinoma and of severe neutro-thrombopenia in a 47-year-old woman with nonfunctioning pituitary adenoma. In two patients (a 34-year-old acromegalic woman and a 39-year-old woman with Nelson's syndrome) no response was observed after 4 and 6 months, respectively, and the treatment was stopped. Conversely, two 52- and 42-year-old women with Cushing's disease had long-term total clinical and radiological remissions which persisted after stopping temozolomide. We conclude that TMZ therapy may be of variable efficacy depending on-until now-incompletely understood factors. Cooperative work on a greater number of cases of aggressive pituitary tumors should be crucial to establish the indications, doses, and duration of temozolomide administration.