Pipestem capillaries in necrotizing myopathy revisited.

Pipestem-capillaries in necrotizing myopathy, have been reported as a feature of a distinct type of myopathy. Here, we analyze four muscle biopsy specimens from patients exhibiting endomysial fibrosis associated with pipestem capillaries using histological and electronmicroscopic techniques. However, only one case displayed all of the originally described features, including necrotic fibres, capillary thickening and lack of a significant lymphocytic inflammation, while one case exhibited striking capillary pathology with minimal necrosis and absence of inflammation, and the other two cases were accompanied by additional pathological features.