Prospective measurement of quality of life in myotonic dystrophy type 1.

INTRODUCTION: Generic patient reported outcome measures have had varied success in tracking QoL in myotonic dystrophy type 1 (DM1). AIM: To analyze changes of Individualized Neuromuscular Quality of Life questionnaire (INQoL) scores in clinic patients with DM1 over a 6-year period. METHOD: Patients completed the INQoL at baseline and after a 6-year period through their attendance in a neurology outpatient clinic. Severity of muscular involvement in DM1 was analyzed using the Muscular Impairment Rating Scale (MIRS). RESULTS: Ninety-nine DM1 patients completed a baseline visit. Sixty-seven of these patients were retested at an interval time. The overall INQoL score improved in our sample of patients (P<.05) as did the following subscales: myotonia (P<.05), pain (P<.05), activities (P<.01), social relationships (P<.01), and body image (P<.05). No changes were observed for the independence and emotions scales. There were no differences in mean change of INQoL scores between patients with worsened MIRS and those with no change in MIRS scale after follow-up (P>.05). CONCLUSION: Individualized Neuromuscular Quality of Life questionnaire scores improved in our cohort of DM1 patients during a 6-year period. INQoL score did not correlate with progression of muscle weakness. This must be better understood before the selection of the instrument for use in trials to measure therapeutic benefit in DM1 patients.

Electrophysiological findings in patients with low density lipoprotein receptor related protein 4 positive myasthenia gravis.

BACKGROUND AND PURPOSE: The aim was to determine the electrophysiological profile of our cohort of low density lipoprotein receptor related protein 4 (LRP4) positive myasthenia gravis (MG) patients. METHODS: A repetitive nerve stimulation (RNS) test and jitter analysis using a concentric needle electrode were performed in 17 LRP4 positive MG patients. The results were compared to 31 muscle-specific tyrosine kinase (MuSK) positive and 28 acetylcholine receptor (AChR) positive MG patients. RESULTS: The RNS test was negative in almost all patients belonging to the LRP4/seronegative and LRP4/MuSK groups. It was positive most frequently in the AChR MG patients, especially those without anti-LRP4 antibodies. The presence of anti-LRP4 antibodies was connected to lower decrement values, whilst the independent presence of anti-AChR or anti-MuSK antibodies was connected to higher decrement values. Lowest jitter was recorded in patients with LRP4/seronegative MG. The highest percentage of pathological jitter analysis test results was present in MuSK and AChR MG patients. The isolate presence of anti-LRP4 antibodies did not influence the mean consecutive difference values, whilst mean consecutive difference values were higher in the presence of anti-AChR or anti-MuSK antibodies. CONCLUSIONS: Low density lipoprotein receptor related protein 4 positive patients make a distinct MG subgroup with rarely detected pathological electrophysiological test results. The lack of influence of anti-LRP4 antibodies on the different electrophysiological parameters brings into question the pathogenic role of anti-LRP4 antibodies in MG.

Five-year study of quality of life in myotonic dystrophy.

Background - Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. There is a complete lack of studies that assessed quality of life (QoL) trajectory during time in DM1 cohorts. Aim - To analyze changes of QoL in patients with DM1 during a 5-year follow-up period and to assess responsiveness of the SF-36 questionnaire. Patients and Method - At the baseline, this study comprised 84 DM1 patients, of whom 62 were retested after the mean period of 64.2 ± 3.9 months. Severity of muscular weakness was assessed using the Muscular Impairment Rating Scale (MIRS). Patients completed Serbian version of the SF-36 questionnaire as a measure of health-related QoL. Results - After 5 years, MIRS score of our DM1 patients showed significant progression of 0.5 grade (P < 0.01). All mental subdomains, role physical, and total SF-36 scores significantly improved after 5 years (P < 0.01). Unexpectedly, worsening of muscular weakness from mild to severe was in association with improvement of QoL. Conclusion - QoL improved in our cohort of DM1 patients during a 5-year period despite the progression of the disease. SF-36 should be used with caution as a patient-reported outcome measure in DM1 clinical trials.

High frequency of DQB1*05 and absolute absence of DRB1*13 in muscle-specific tyrosine kinase positive myasthenia gravis.

BACKGROUND AND PURPOSE: Myasthenia gravis (MG) is an autoimmune disease but certain genetic factors predispose its development. Since susceptibility to different forms of MG is linked to a number of allelic variants, the aim of this study was to explore the human leukocyte antigen (HLA) profile of our patients with muscle-specific tyrosine kinase (MuSK) MG. METHODS: Human leukocyte antigen (HLA) typing was performed in our cohort of 31 MuSK MG patients available for the study. The allele groups of DRB1* and DQB1* loci were typed with sequence-specific oligonucleotide probes and high resolution typing for DQB1* was performed using sequence-specific primers. HLA frequencies were compared with unrelated healthy bone marrow donors. RESULTS: Significant association of MuSK MG with alleles DRB1*14 [odds ratio (OR) 3.8], DRB1*16 (OR 3.3) (P < 0.01) and DQB1*05 (OR 2.2) (P < 0.05) was found. In our patients the most frequent DQB1* allele was DQB1*05:02. An absolute absence of DRB1*13 in our cohort of MuSK MG patients was also found, whilst this allele was present in 25% (495/1992) of control subjects (OR 0) (P < 0.01). The HLA DRB1*16-DQB1*05 (OR 2.9) haplotype was found to be associated with MuSK MG (P < 0.05). CONCLUSIONS: The strong association of MuSK MG with DQB1*05 alleles observed in patient series from other countries was confirmed. The novel finding in our cohort of MuSK MG patients was the absolute absence of DRB1*13 allele, which might have a protective role in the development of MuSK MG, at least in our population.

A comprehensive analysis of the epidemiology and clinical characteristics of anti-LRP4 in myasthenia gravis.

Double-seronegative myasthenia gravis (dSN-MG, without detectable AChR and MuSK antibodies) presents a serious gap in MG diagnosis and understanding. Recently, autoantibodies against the low-density lipoprotein receptor-related protein 4 (LRP4) have been identified in several dSN-MG sera, but with dramatic frequency variation (∼2-50%). We have developed a cell based assay (CBA) based on human LRP4 expressing HEK293 cells, for the reliable and efficient detection of LRP4 antibodies. We have screened about 800 MG patient sera from 10 countries for LRP4 antibodies. The overall frequency of LRP4-MG in the dSN-MG group (635 patients) was 18.7% but with variations among different populations (range 7-32.7%). Interestingly, we also identified double positive sera: 8/107 anti-AChR positive and 10/67 anti-MuSK positive sera also had detectable LRP4 antibodies, predominantly originating from only two of the participating groups. No LRP4 antibodies were identified in sera from 56 healthy controls tested, while 4/110 from patients with other neuroimmune diseases were positive. The clinical data, when available, for the LRP4-MG patients were then studied. At disease onset symptoms were mild (81% had MGFA grade I or II), with some identified thymic changes (32% hyperplasia, none with thymoma). On the other hand, double positive patients (AChR/LRP4-MG and MuSK/LRP4-MG) had more severe symptoms at onset compared with any single positive MG subgroup. Contrary to MuSK-MG, 27% of ocular dSN-MG patients were LRP4 antibody positive. Similarly, contrary to MuSK antibodies, which are predominantly of the IgG4 subtype, LRP4 antibodies were predominantly of the IgG1 and IgG2 subtypes. The prevalence was higher in women than in men (female/male ratio 2.5/1), with an average disease onset at ages 33.4 for females and 41.9 for males. Overall, the response of LRP4-MG patients to treatment was similar to published responses of AChR-MG rather than to MuSK-MG patients.

Dependent and paranoid personality patterns in myotonic dystrophy type 1.

OBJECTIVES: To analyze frequency and type of personality pattern in patients with myotonic dystrophy type 1 (DM1), to correlate these findings with clinical data, and to assess its possible influence on quality of life (QoL). MATERIALS AND METHODS: This cross-sectional study comprised 62 patients with DM1. Following measures were used: Muscular Impairment Rating Scale, Raven's Standard Progressive Matrices (RSPM), Millon Multiaxial Clinical Inventory I (MMCI), SF-36, and Individualized Neuromuscular Quality of Life (INQoL) questionnaires. RESULTS: The presence of at least one pathological personality trait with score above 85 on MMCI was found in 47 (75.8%) patients. After clinical interview, 36 (58.1%) subjects had significant personality impairment. The most common personality trait in our cohort of patients was dependent found in 51.6% of patients, followed by paranoid (38.7%). Higher score on dependent personality scale correlated with lower education (rho = -0.251, P = 0.049). Dependent personality scores significantly differed between patients with physical and intellectual work (93.1 ± 8.9 vs 66.9 ± 31.7, P = 0.011). Paranoid score was higher in patients with lower education (rho = -0.293, P = 0.021), lower score on RSPM test (rho = -0.398, P = 0.004) and larger number of CTG repeats (rho = 0.254, P = 0.046). Presence of dependent personality was not in association with QoL scores (P > 0.05). On the other hand, patients with paranoid personality trait had worse QoL than those without it (P < 0.05). CONCLUSION: Almost 60% of our patients with DM1 had clinically significant personality impairment, with dependent and paranoid personality patterns being the most common. Paranoid personality may decrease QoL in these patients, which gives us new opportunities for symptomatic therapy in DM1.

Epidemiological study of adult-onset myasthenia gravis in the area of Belgrade (Serbia) in the period 1979-2008.

BACKGROUND: The aim of this study was to analyze the prevalence and incidence of adult-onset myasthenia gravis (MG) in the Belgrade population from 1979 to 2008. METHODS: Data on the number of MG patients and their basic demographic and clinical characteristics were collected from hospital records (1979-1992) and the Belgrade MG Registry (1993-2008). Incidence and prevalence were standardized by the direct method (using the world standard population). A time-trend analysis of MG incidence was performed using a linear regression model. RESULTS: During the study period 562 cases (316 women, 246 men) were registered. On December 31st, 2008, the standardized prevalence (according to the world standard population) was 188.3/1,000,000 (women: 237.8/1,000,000; men: 139.4/1,000,000). The average annual standardized incidence rate was 13.3/1,000,000 (women: 14.1/1,000,000; men: 12.2/1,000,000). The incidence rates tended to increase significantly in both sexes during the study period (y = 3.299 + 14.363x, p = 0.002). Age-specific incidence rates for women demonstrated a bimodal pattern, with the first peak in the 20- to 29-year age group and the second one in the ≥70-year group. For both genders, an increase in age-specific incidence rates was registered for all age groups, although this was significant (p = 0.001) only for an MG onset of ≥60 years of age. CONCLUSIONS: The study confirms an increase in the incidence of MG in the area of Belgrade during the study period, especially for those with MG onset after 60 years of age.

Validation of Serbian version of the disease-specific myasthenia gravis questionnaire.

AIM: The aim of this study was to validate translated and cross-cultural adapted Italian version of myasthenia gravis-specific questionnaire (MGQ) in Serbian MG patients. MATERIALS AND METHODS: The questionnaire was validated in 140 consecutive MG patients from Belgrade. In each patient association between the total MGQ score and form and severity of the disease was determined. Also, correlation between regional domain scores of MGQ and main clinical findings according to Besinger's clinical score was analyzed. RESULTS: Patients' participation in the assessment was satisfactory with excellent internal consistency and reproducibility. Total MGQ score, as well as domain scores, correlated with highly significant inverse relationship with the disease severity and clinical status of patients at the moment of completing the questionnaire. Furthermore, the bulbar domain of the questionnaire appeared more specific and sensitive than clinical history and examination. CONCLUSION: We concluded that the Serbian version of the MGQ may be useful as a measure of clinical outcome in patients with MG.

Leptin and the metabolic syndrome in patients with myotonic dystrophy type 1.

OBJECTIVES: To evaluate serum leptin concentration and its relation to metabolic syndrome (MSy) in non-diabetic patients with myotonic dystrophy type 1 (DM1). MATERIALS AND METHODS: This study included 34 DM1 patients, and the same number of healthy subjects matched for age, sex and body mass index (BMI). RESULTS: DM1 patients had increased BMI and insulin resistance, and increased leptin and insulin concentrations, but the other features of MSy such as diabetes, glucose intolerance and hypertension were not detected in DM1 patients. Serum leptin levels were higher in patients with DM1 than in healthy controls (8.5 +/- 6.6 ng/ml vs 3.6 +/- 2.9 ng/ml in men, and 13.9 +/- 10.0 ng/ml vs 10.9 +/- 6.9 ng/ml in women, respectively). In DM1 patients, leptin levels correlated with BMI, fasting insulin and insulin resistance (HOMA) (P < 0.01). CONCLUSIONS: The leptin overproduction correlated with insulin resistance in DM1 patients but the significance of this finding remains unclear.

Health-related quality of life in patients with myotonic dystrophy type 1 and amyotrophic lateral sclerosis.

The aim was to assess factors that might influence health-related quality of life (HRQoL) in patients with two different neuromuscular disorders - myotonic dystrophy type 1 (DM1) and amyotrophic lateral sclerosis (ALS). A cross-sectional study was performed on 79 patients with DM1 and 74 with ALS. The HRQoL was evaluated by SF-36, Serbian version. Depressive and anxiety symptoms were assessed using the Hamilton rating scale for depression and the Hamilton rating scale for anxiety respectively. Severity of muscular involvement in DM1 was measured with MRC scale and severity of ALS with ALSFRSr score. The mean total score as well as all domain scores of SF-36 were similar in DM1 and ALS patients (p > 0.05), except that ALS patients experienced less bodily pain (p < 0.05). Depressiveness was found in 51% and marked anxiety in 38% of DM1 patients. Emotional status and severity of muscular involvement emerged as significant independent contributing factors to the total SF-36 in DMI patients (p < 0.05). Only 3% of ALS patients showed depressiveness and 4% anxiety symptoms. The factors found to contribute to HRQoL in ALS patients were severity of disease and educational level ofpatients (p < 0.05). We found significant percentage of potentially treatable emotional disturbances which together with severity of disease significantly contributed to HRQoL in DM1 patients. On the other hand, in ALS patients depressiveness and anxious symptoms were uncommon and the factors found to contribute to HRQoL were severity of disease and educational level.

Prospective analysis of gait characteristics in chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disorder that may lead to functional impairment, including gait abnormalities. Our aim was to analyze gait characteristics in patients with CIDP compared to healthy controls (HC). Moreover, we sought to determine changes of gait parameters after six-month follow-up period. Twenty-four patients with CIDP and 24 HCs performed basic walking task, dual-motor task, dual-mental task, and combined task using the same GAITRite system. Lower limb MRC-SS and lower limb INCAT disability score were assessed. Fourteen patients were retested after six months. Majority of gait parameters showed significant differences in all experimental conditions when compared between CIDP and HCs. The most consistent findings in CIDP were shorter stride length (SL), prolonged cycle time (CT) and double support time (DS), as well as increased variation of SL and of swing time (ST) (p < 0.05). During follow-up, INCAT improved in nine (64.3%) of 14 patients and MRC-SS improved in eight (57.1%) patients. Six-month changes of CT and its variation during combined task significantly differentiated patients with improved vs. non-improved INCAT (p < 0.05). In conclusion, patients with CIDP had slower gait with prolonged DS and with shorter SL compared to HCs. Increased variation of SL and of ST in CIDP may suggest a potential risk for instability and falls. Shorter CT duration and less CT variation during time correlated well with improvement in disability.

Intravenous immunoglobulin therapy in two patients with myasthenia gravis and pemphigus vulgaris.

UNLABELLED: Various forms of pemphigus have been reported to occur with myasthenia gravis (MG), with and without thymoma. We described two cases of pemphigus vulgaris associated with MG without thymoma. Case 1. A 44 year-old woman presented with 3 years history of pemphigus vulgaris. Three years later, she developed myasthenic symptoms with elevated level of anti-acetylcholine receptor (AChR) antibodies - 5.2 nmol/L. She was thymectomised and we revealed only hyperplastic thymus. Case 2. A 64-year-old woman had a general fatigue and intermittent double vision. She was diagnosed as MG three years later. Two months before she diagnosed as MG, she had pruritic erythematous, erosive and bullous lesions on her body and extremities. Oral prednisolon, pyridostigmine bromide and azathioprine or cyclophosphamide didn't adequately control MG and pemphigus in our patients, so they received intravenous immunoglobulins of 0.4 g/kg for 5 consecutive days. After that therapy, our patients markedly improved. CONCLUSION: The precise pathological mechanisms of the association between pemphigus and MG are not fully understood. The thymus has been suggested to be a possible common origin of autoimmune response in these disorders.

Hereditary motor and sensory neuropathy Lom type in a Serbian family.

Hereditary motor and sensory neuropathy Lom type (HMSNL), also called CMT 4D, a hereditary autosomal recessive neuropathy, caused by mutation in N-Myc downstream regulated gene 1 (NDRG1 gene), was first described in a Bulgarian Gypsy population near Lom and later has been found in Gypsy communities in Italy, Spain, Slovenia and Hungary. We present two siblings with HMSNL, female and male, aged 30 and 26, respectively in a Serbian non-consanguineous family of Gypsy ethnic origin. They had normal developmental milestones. Both had symptoms of lower limb muscle weakness and walking difficulties with frequent falls, which began at the age of seven. At the age of 12, they developed hearing problems and at the age of 15 hand muscle weakness. Neurological examination revealed sensorineural hearing loss, dysarthria, severe distal and mild proximal muscle wasting and weakness, areflexia and impairment of all sensory modalities of distal distribution. Electrophysiological study revealed denervation with severe and early axonal loss. Sensorineural hearing loss was confirmed on electrocochleography and brainstem evoked potentials. Molecular genetic testing confirmed homozygote C564t (R148X) mutation in NDRG1 gene.

Cardiac autonomic nervous system in patients with myotonic dystrophy type 1.

The purpose of the present study was to evaluate cardiac autonomic nervous system (ANS) in patients with myotonic dystrophy type 1 (DM1). The function of ANS was studied in 20 patients with DM1 and 15 healthy controls. All subjects were investigated by a battery of six cardiovascular autonomic tests and power spectral analysis of heart rate variability (HRV). Only one patient had normal autonomic function. Two (10%) patients had mild, 10 (50%) moderate and 7 (35%) severe autonomic dysfunction. Thirteen (65%) patients had vagal and 4 (20%) sympathetic hyperactivity. Seven (35%) patients had vagal and 15 (75%) sympathetic dysfunction. Eighteen (90%) patients had orthostatic hypotension. The 24-hour time domain parameters of SDNN (SD of the NN interval) and total power were significantly lower in DM1 patients than in healthy controls (p < 0.05). However, other parameters of HRV, such as SDANN (SD of the mean NN, 5-minute interval), low frequency (LF), high frequency (HF) power and the LF/HF ratio were somewhat lower in patients with DM1 than in controls, but this was not statistically significant. There was no significant relationship between autonomic dysfunction and the severity of the disease or CTG repeat length. There was also no correlation between HRV and age. Our findings suggest that sympathetic dysfunction and vagal predominance may both occur in patients with DM1.

Titin antibodies in "seronegative" myasthenia gravis--A new role for an old antigen.

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies targeting the neuromuscular junction of skeletal muscles. Triple-seronegative MG (tSN-MG, without detectable AChR, MuSK and LRP4 antibodies), which accounts for ~10% of MG patients, presents a serious gap in MG diagnosis and complicates differential diagnosis of similar disorders. Several AChR antibody positive patients (AChR-MG) also have antibodies against titin, usually detected by ELISA. We have developed a very sensitive radioimmunoprecipitation assay (RIPA) for titin antibodies, by which many previously negative samples were found positive, including several from tSN-MG patients. The validity of the RIPA results was confirmed by western blots. Using this RIPA we screened 667 MG sera from 13 countries; as expected, AChR-MG patients had the highest frequency of titin antibodies (40.9%), while MuSK-MG and LRP4-MG patients were positive in 14.6% and 16.4% respectively. Most importantly, 13.4% (50/372) of the tSN-MG patients were also titin antibody positive. None of the 121 healthy controls or the 90 myopathy patients, and only 3.6% (7/193) of other neurological disease patients were positive. We thus propose that the present titin antibody RIPA is a useful tool for serological MG diagnosis of tSN patients.

Congenital myopathy with uniform type 1 fibers.

Congenital myopathy with uniform type 1 fibers is a rare form of nonprogressive congenital neuromuscular disease. We report a 40 year old woman with proximal muscle weakness, waddling gait and decreased deep tendon reflexes. The serum creatine kinase level was decreased. Peripheral nerve conduction velocity as well as electrocardiogram and echocardiogram were normal. The electromyogram showed myopathic changes. A biopsy specimen from the left deltoid muscle revealed a uniformity of type 1 fibers. This is the first case of congenital myopathy with uniform type 1 fibers reported in Serbia.

MuSK autoantibodies in myasthenia gravis detected by cell based assay--A multinational study.

Seronegative myasthenia gravis (MG) presents a serious gap in MG diagnosis and understanding. We applied a cell based assay (CBA) for the detection of muscle specific kinase (MuSK) antibodies undetectable by radioimmunoassay. We tested 633 triple-seronegative MG patients' sera from 13 countries, detecting 13% as positive. MuSK antibodies were found, at significantly lower frequencies, in 1.9% of healthy controls and 5.1% of other neuroimmune disease patients, including multiple sclerosis and neuromyelitis optica. The clinical data of the newly diagnosed MuSK-MG patients are presented. 27% of ocular seronegative patients were MuSK antibody positive. Moreover, 23% had thymic hyperplasia suggesting that thymic abnormalities are more common than believed.

Pathohistological changes in endomyocardial biopsy specimens in patients with myotonic dystrophy.

BACKGROUND: Endomyocardial biopsies in patients with myotonic dystrophy (MD) have, so far, shown changes such as myofibrillar degeneration, mitochondrial abnormalities, focal myocarditis, fibrosis and fatty infiltration of the myocardium and the conduction system. METHODS: This study presents the results of endomyocardial biopsy in 10 patients with MD. Endomyocardial biopsy was carried out using King's bioptome. RESULTS: In two patients with servere MD biopsy specimens showed changes compatible with border line myocarditis. In five patients with moderate to severe forms of MD fibrosis and fatty infiltration of the myocardium were found in addition to degenerative changes and hypertrophy of muscle fibers. Three patients with mild MD had non-specific degenerative and hypertrophic myocardial changes. The histological changes described above were present in patients without cardiological symptoms and in those with normal ECG and echocardiographic findings. Only two of the 10 patients in whom endomyocardial biopsy was done complained of fatigue and occasional palpitations while the rest were asymptomatic. One patient with focal myocarditis had ECG signs of left bundle branch block and echocardiographic evidence of reduced left ventricular contractility. Five patients with signs of endomyocardial fibrosis only had an abnormal Q wave on ECG recordings. The remaining five patients with border line myocarditis i.e. with degenerative and hypertrophic myocardial changes had normal ECG and echocardiographic findings. CONCLUSIONS: These results stress the significance of endomyocardial biopsy in detecting myocardial pathologic changes in patients with MD.

Myotonic dystrophy and cardiac disorders.

Myotonic dystrophy (MD) is a multisystem disease affecting numerous organs and systems. Cardiac involvement is frequent. Sudden death, due to fatal cardiac rhythm and conduction disturbances occurs in 30% of patients with MD. The aim of this study was to assess the possibilities and methods of early detection of myocardial and conduction system disturbances. ECG, 24-hr Holter monitoring, echocardiography and electrophysiologic studies of the conduction system (electrophysiologic study) were carried out in 45 patients. Analysis of late ventricular potentials was done in 36 patients. Genetic studies revealed multiplication of CTG triplets in all patients. Cardiological abnormalities were detected in 89% of our patients. Disturbances of intraventricular conduction with prolongation of HV interval were most frequent (72%). Electrophysiologic study was the most sensitive method for detecting heart involvement in MD (positive findings in 87% patients). Abnormal findings were also discovered by Holter monitoring (64%), ECG (58%), analysis of late ventricular potentials (55%) and by echocardiography in 46% patients. The results of this study indicate a high rate of cardiac involvement in MD.

Extrathymic malignancies in a defined cohort of patients with myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) may be associated with extrathymic malignancies, especially in patients with thymoma. AIM: To determine the frequency and type of extrathymic malignancies in MG patients from the Belgrade area, and to identify potential risk factors associated with tumors. PATIENTS AND METHOD: The study comprised 390 patients with MG. Different sociodemographic and clinical variables potentially associated with extrathymic neoplasms were analyzed. RESULTS: Extrathymic malignancies were present in 42 (10.8%) MG patients - 22 (52.4%) males and 20 (47.6%) females. The most frequently detected were breast (40%) and lung (40%) neoplasms. The tumors appeared with similar frequency before (45.2%) and after the onset of MG (42.9%). Significant predictors for the development of extrathymic malignancies were current age (p = 0.001) and immunoglobulin (IVIg) therapy (p = 0.021). On the other hand, current age (p=0.001), longer MG duration (p = 0.001) and generalized form of MG (p = 0.002) were significant predictors of malignancy occurring after the MG onset. CONCLUSION: Our study revealed that older MG patients, as well as those with longer duration of the disease, and those who received IVIg therapy had a higher oncogenic risk for the development of extrathymic malignancies.