Microfibrillar cardiomyopathy: A rare case.

Microfibrillar cardiomyopathy is a very rare cause of restrictive cardiomyopathy (RCM). The index case was a male patient who presented with shortness of breath and pedal edema. Further clinical investigations favored a clinical diagnosis of RCM. An endomyocardial biopsy revealed subendocardial and interstitial hyaline eosinophillic material resembling amyloid that did not stain with Congo red. An electron microscopic examination showed that this material was composed of twisted linear and bundles of tangled microfibrils. The etiology of the microfibrillar deposition is currently unknown. The pathologists should entertain the diagnosis of microfibrillar cardiomyopathy in suspected cases of amyloidosis that are negative for Congo red.

A Case of Idiopathic Fibrillary Glomerulonephritis with Hypocomplementemia / 대한신장학회지

A 72-year-old woman presented with generalized edema and proteinuria. Renal biopsy disclosed highly organized fibrillary deposits in subendothelial area by electron microscopy. The microfibrils were 14 nm in diameter and randomly arranged. They did not have a microtubular appearance. These materials were negative for Congo red staining. Cryoglobulinemia or paraproteinemia including light chains was not found. So we can diagnose her as fibrillary glomerulonephritis (GN). In fibrillary GN serum complement levels are usually normal except in rare cases with systemic disease. Here we present a rare case of fibrillary GN with unusual hypocomplementemia.

Histopathological Study of Extraocular Musele followinr Posterior Fixation Suture in Rabbits: Pathogenesis of Musele Fibrosis

The authors observed the histological and ultrastructural findings in a study of the fibrosis of the extraocular muscles following a posterior fixation suture in rabbits. the early findings demonstrated hyalinosis, clumping of the nuclei of muscle cells and collagenization of the muscle tissue. However, there was no evidence of collagen tissue in the degenerated muscle fiber, reserving cell membrane and basement membrane ultrastructurally. The late findings showed splitting and irregular stain of the muscle fibers, many nuclei of presumed muscle cell and filamentous structure at the collagen tissue in the extracellular space. Electron microscopic study showed atrophy and angulation with distortion of the myofibrillar matrix, along with other cytoplasmic degenerative phe nomena in the muscle fibers. Clumps of the well-arranged microfibrils(Mf) and irregularly arranged Mf with fine granular materials(FGM) were adjacent to the immature collagen fibrils. Many of the Mf and FGM were closely associated, and the number of the Mf and FGM decreased with the degree of maturity of the collagen fibrils. The anatomical structure of the myofibrill was identified as that of the Mf. From these findings, it would appear that formation of collagen fiber occurs in the extracellular space and that Mf and FGM are primarily responsible for the formation of the collagen fibils.