Radiology of epiploic appendages: acute appendagitis, post-infarcted appendages, and imaging natural history.

Our aim was to demonstrate the imaging characteristics of epiploic appendages in native, acute inflamed/ischemic and post-infarcted states through retrospective imaging analysis, with clinical and pathologic correlation, and to discuss clinical implications. Cases were gathered mostly retrospectively and reviewed for inclusion based on established diagnostic criteria. Radiology report text search was used to find cases, using terms "epiploic," "appendage," "appendagitis," and "peritoneal body." Data records included patient demographics, relevant clinical data, lesion size, location and apparent imaging composition, and the presence of change or stability in features over multiple studies. Pathologic and clinical data were sought and assessed for correlation. Imaging studies of 198 individuals were included (mean age 50, range 9-95), with a total of 228 lesions: 63 acute and 165 non-acute presentations. All included subjects had CT imaging and some had lesions visible on radiographs, MRI, PET/CT, and sonography. 23 subjects had more than one studied lesion. In addition to classic acute appendagitis, more frequently encountered are post-infarcted appendages either in situ along the colon, adhered to peritoneal or serosal surfaces, or freely mobile in the peritoneum as loose bodies. The majority of the non-acute varieties are recognizable due to peripheral calcification that develops over time following ischemic insult. Multiple cases demonstrated the imaging natural history and confirmed pathologic basis for imaging findings. In summary, acute and post-infarcted epiploic appendages have characteristic imaging appearances and natural history which should provide correct diagnosis in most cases. Incidental post-infarcted epiploica are more commonly encountered than acute presentations.

Vanishing bone metastases: a pitfall in contrast-enhanced CT in patients with venous thrombosis.

Enhancement patterns of visceral venous collaterals are well documented in cases of superior vena cava obstruction. Only recently has intraosseous venous collateral enhancement been described. We describe an unusual case of vertebral marrow enhancement in the lower thoracic spine related to venous collateral circulation caused by an incidental hemiazygos thrombus. Misinterpretation of this finding can lead to the erroneous interpretation of sclerotic bone metastases.

Clinical course correlates poorly with muscle pathology in nemaline myopathy.

OBJECTIVE: To report pathologic findings in 124 Australian and North American cases of primary nemaline myopathy. METHODS: Results of 164 muscle biopsies from 124 Australian and North American patients with primary nemaline myopathy were reviewed, including biopsies from 19 patients with nemaline myopathy due to alpha-actin (ACTA1) mutations and three with mutations in alpha-tropomyosin(SLOW) (TPM3). For each biopsy rod number per fiber, percentage of fibers with rods, fiber-type distribution of rods, and presence or absence of intranuclear rods were documented. RESULTS: Rods were present in all skeletal muscles and diagnosis was possible at all ages. Most biopsies contained nemaline bodies in more than 50% of fibers, although rods were seen only on electron microscopy in 10 patients. Rod numbers and localization correlated poorly with clinical severity. Frequent findings included internal nuclei and increased fiber size variation, type 1 fiber predominance and atrophy, and altered expression of fiber type specific proteins. Marked sarcomeric disruption, increased glycogen deposition, and intranuclear rods were associated with more severe clinical phenotypes. Serial biopsies showed progressive fiber size variation and increasing numbers of rods with time. Pathologic findings varied widely in families with multiple affected members. CONCLUSIONS: Very numerous nemaline bodies, glycogen accumulation, and marked sarcomeric disruption were common in nemaline myopathy associated with mutations in skeletal alpha-actin. Nemaline myopathy due to mutations in alpha-tropomyosin(SLOW) was characterized by preferential rod formation in, and atrophy of, type 1 fibers. Light microscopic features of nemaline myopathy correlate poorly with disease course. Electron microscopy may correlate better with disease severity and genotype.

Nemaline myopathy: a clinical study of 143 cases.

We report 143 Australian and North American cases of primary nemaline myopathy. As classified by the European Neuromuscular Centre guidelines, 23 patients had severe congenital, 29 intermediate congenital, 66 typical congenital, 19 childhood-onset, and 6 adult-onset nemaline myopathy. Inheritance was autosomal recessive in 29 patients, autosomal dominant in 41, sporadic in 72, and indeterminate in 1. Twenty-two patients had skeletal muscle actin mutations and 4 had mutations in the alpha-tropomyosin(slow) gene. Obstetric complications occurred in 49 cases. Seventy-five patients had significant respiratory disease during the first year of life, and 79 had feeding difficulties. Atypical features in a minority of cases included arthrogryposis, central nervous system involvement, and congenital fractures. Progressive distal weakness developed in a minority of patients. Thirty patients died, the majority during the first 12 months of life. All deaths were due to respiratory insufficiency, which was frequently underrecognized in older patients. Arthrogryposis, neonatal respiratory failure, and failure to achieve early motor milestones were associated with early mortality. Morbidity from respiratory tract infections and feeding difficulties frequently diminished with increasing age. Aggressive early management is warranted in most cases of congenital nemaline myopathy.

Dystrophin expression in the mdx mouse restored by stem cell transplantation.

The development of cell or gene therapies for diseases involving cells that are widely distributed throughout the body has been severely hampered by the inability to achieve the disseminated delivery of cells or genes to the affected tissues or organ. Here we report the results of bone marrow transplantation studies in the mdx mouse, an animal model of Duchenne's muscular dystrophy, which indicate that the intravenous injection of either normal haematopoietic stem cells or a novel population of muscle-derived stem cells into irradiated animals results in the reconstitution of the haematopoietic compartment of the transplanted recipients, the incorporation of donor-derived nuclei into muscle, and the partial restoration of dystrophin expression in the affected muscle. These results suggest that the transplantation of different stem cell populations, using the procedures of bone marrow transplantation, might provide an unanticipated avenue for treating muscular dystrophy as well as other diseases where the systemic delivery of therapeutic cells to sites throughout the body is critical. Our studies also suggest that the inherent developmental potential of stem cells isolated from diverse tissues or organs may be more similar than previously anticipated.