No abstract available.
Microscopy, Electron* ; Muscular Diseases* ; Pathology*

Evans myopathy is a type of malignant hyperthermia showing characteristic distribution of myopathic changes. We present two cases of Evans myopathy, father and his son in a family. Five members of this family expired during ane sthesia and surgery and two of these cases were reported as the malignant hyperthermia. The muscle pathology shows moth-eaten appearance with or without unstained cores in NADH-TR stain and its difference between the father and his son is suggestive of rather progressive myopathy than static one. s
Fathers ; Humans ; Malignant Hyperthermia ; Muscular Diseases* ; Pathology

Congenital muscle fiber type disproportion (CFTD) has been described as a form of congenital myopathy characterized by the smallness and marked predominance of type 1 fibers in a muscle biopsy. Clinical manifestations include hypotonia, nonprogressive muscle weakness, joint contractures, and skeletal deformities. However, it has also been noted that the same pathologic alterations appeared in clinically diverse conditions. Recently, we experienced a family, a mother and two children, in which a muscle biopsy showed the mother to have muscle fiber type disproportion. This case was unusual in that there was a significant progression of weakness, an absence of neonatal hypotonia, and other commonly associated musculo-skeletal deformities. In this report, we describe the clinicopathologic features of the family with a brief review about muscle fiber type disproportion.
Adult ; Biopsy ; Child, Preschool ; Female ; Human ; Male ; Muscle Fibers/pathology* ; Muscular Diseases/pathology ; Muscular Diseases/genetics*

Histopathological findings of eosinophilic myositis in the carcass of a slaughtered Korean native cow are presented. Lesions contained massive fibrous septae with vacuolar changes in some lesions, and the hypercontraction and rupturing of muscle bundles, with replacement by eosinophils. Necrosis and severe eosinophil infiltration were observed. Sarcoplasmic fragmentation and atrophy developed. Typical of granuloma, calcified myofibers were focally surrounded by macrophages and numerous inflammatory cells, and multinucleated giant cell formation was evident.
Animals ; Cattle ; Cattle Diseases/*pathology ; Eosinophilia/pathology/*veterinary ; Female ; Muscle, Skeletal/*pathology ; Muscular Diseases/pathology/*veterinary

Muscular dystrophy (MD) is a heterogeneous group of inherited muscle disorders caused by the mutations of different genes encoding muscle proteins, and it is now classified according to the results of the linkage analysis and the genes or proteins affected. Except for some subtypes of MD presenting with characteristic manifestations, differential diagnosis is always a challenging task to clinicians because of the similarities in clinical features and muscle pathology findings between subtypes. The immunohistochemical stain (IHC) using a biopsied skeletal muscle is an effective and simplest way to identify defective proteins in MD, so that we can classify MD into its subtypes and target the affected gene. The frozen muscle sections are used for the IHC, and specialized procedures of fixation, blocking, antibody reaction, and detection are serially performed. By using sets of commercially available antibodies, we can identify many different subtypes of MD, which include dystrophinopathies, several forms of limb-girdle muscular dystrophies, and subgroups of congenital muscular dystrophies. Although each disease shows its own characteristic patterns on IHC, there are some exceptional cases including normal expression of the mutated protein and secondary loss of the unaffected protein. Since the quality of the IHC results largely depends on technique and experience, the choice of antibody panel for IHC should be individualized in each laboratory considering the number of muscle biopsy requests, available technicians, and expenses for the study.
Antibodies ; Biopsy ; Diagnosis, Differential ; Immunohistochemistry ; Muscle Proteins ; Muscle, Skeletal ; Muscular Diseases ; Muscular Dystrophies* ; Muscular Dystrophies, Limb-Girdle ; Pathology

BACKGROUND AND PURPOSE: Hyperkalemic periodic paralysis (hyperKPP) is a muscle sodium-ion channelopathy characterized by recurrent paralytic attacks. A proportion of affected individuals develop fixed or chronic progressive weakness that results in significant disability. However, little is known about the pathology of hyperKPP-induced fixed weakness, including the pattern of muscle involvement. The aim of this study was to characterize the patterns of muscle involvement in hyperKPP by whole-body magnetic resonance imaging (MRI). METHODS: We performed whole-body muscle MRI in seven hyperKPP patients carrying the T704M mutation in the SCN4A skeletal sodium-channel gene. Muscle fat infiltration, suggestive of chronic progressive myopathy, was analyzed qualitatively using a grading system and was quantified by the two-point Dixon technique. RESULTS: Whole-body muscle MRI analysis revealed muscle atrophy and fatty infiltration in hyperKPP patients, especially in older individuals. Muscle involvement followed a selective pattern, primarily affecting the posterior compartment of the lower leg and anterior thigh muscles. The muscle fat fraction increased with patient age in the anterior thigh (r=0.669, p=0.009), in the deep posterior compartment of the lower leg (r=0.617, p=0.019), and in the superficial posterior compartment of the lower leg (r=0.777, p=0.001). CONCLUSIONS: Our whole-body muscle MRI findings provide evidence for chronic progressive myopathy in hyperKPP patients. The reported data suggest that a selective pattern of muscle involvement-affecting the posterior compartment of the lower leg and the anterior thigh-is characteristic of chronic progressive myopathy in hyperKPP.
Channelopathies ; Humans ; Leg ; Magnetic Resonance Imaging* ; Muscles ; Muscular Atrophy ; Muscular Diseases* ; Paralysis, Hyperkalemic Periodic* ; Pathology ; Thigh

Fibromatosis of the temporal region is extremely rare. It has also been referred to as extra-abdominal desmoid which orininates from muscle or fascia and it is a highly recurrent tumor. This paper presents a case of temporal muscle fibromatosis and a brief review of the pertinent literature.
Female ; Fibroma/pathology* ; Human ; Masticatory Muscles*/pathology ; Middle Age ; Muscular Diseases/pathology* ; Temporal Muscle*/pathology

Adult ; Amyloidosis ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Muscular Diseases ; pathology ; surgery ; Neck Muscles ; pathology ; surgery

Central core disease is a rare congenital myopathy characterized by the formation of cores that consist of abnormal arrangement of myofibrils inside the myofibers. We report a 5-year-old Korean girl who showed a fairly typical clinical course of non-progressive muscle weakness. Electrodiagnostic studies showed low-amplitude polyphasic electromyograph and normal nerve conduction velocity. Gastrocnemius muscle biopsy showed central cores in over 80% of the fibers on H&E section. Histochemistry revealed deficient or absent mitochondrial enzyme in the cores and type I predominance. Ultrastructurally both structured and non-structured cores were found separately or simultaneously in one fiber. This case is the first report in the Korean literature.
Child, Preschool ; Female ; Humans ; Microscopy, Electron ; Muscles/pathology/ultrastructure ; Muscular Diseases/*congenital/*pathology

Multicore myopathy is a rare congenital myopathy. The multicores consist of numerous small areas of decreased oxidative enzyme activity. The long axis of the lesion is perpendicular or parallel to the long axis of the muscle fiber. These cores are usually smaller than central cores. For this reason they are also called minicores. Although the multicores represent a nonspecific change in that they can be observed in malignant hyperthermia, muscular dystrophy, inflammatory myopathy, etc. Muscular weakness dating from early infancy is combined large proportion of the muscle fibers. In about half of the reported cases the muscular weakness has not been progressive, while in the others a slow progression has occurred. This 9-year-old boy presented with congenital nonprogressive myopathy associated with thoracic scoliosis and bilateral equinovarus deformity. The serum creatine phosphokinase and lactic dehydrogenase levels were normal. Electromyography showed "myopathic" features. The biopsy revealed a marked size variation in myofibers, ranging from 10 microns to 100 microns. A few small angular fibers and slight endomyseal fibrosis were also noted. There was type I fiber predominance. NADH-TR reaction disclosed more well-defined cores with loss of intermyofibrillary mitochondrial activity. These cores were usually located with loss of intermyofibrillary mitochondrial activity. These cores were usually located in the peripheral portions of the myofibers and the core size measured 10-30 microns in diameter. Electron microscopic examination revealed circumscribed areas of disintegrated Z band material and disorganized sarcomeric units near the sarcolemma. A decrease in the number of mitochondria and glycogen particles was noted.
Biopsy ; Child ; Histocytochemistry ; Humans ; Korea ; Male ; Microscopy, Electron ; Muscles/pathology/ultrastructure ; Muscular Diseases/*pathology