%0 Journal Article
%T Histopathological, Ultrastructural, and Immunohistochemical Findings in MYH11-Variant Visceral Myopathy.
%A Kapur RP
%J Pediatr Dev Pathol
%V 26
%N 1
%D Jan-Feb 2023
%M 36571289
%F 2.266
%R 10.1177/10935266221128133
%X <B>UNASSIGNED: </B>Pathogenic mutations in the smooth muscle myosin heavy chain gene, MYH11, cause megacystis megacolon intestinal hypoperistalsis syndrome and other forms of chronic intestinal pseudo-obstruction. Evaluation of intestinal tissues from affected patients is often performed before mutational analysis, but the pathological findings of MYH11-variant visceral myopathy have not been well defined.<BR><B>UNASSIGNED: </B>Light microscopic, immunohistochemical, and ultrastructural findings from multiple intestinal samples from 2 patients with MYH11-variant visceral myopathy were reviewed, including MYH11-specific immunohistochemistry. The findings were compared with intestinal samples from patients with gamma-smooth muscle actin (ACTG2)-variant visceral myopathy and non-pseudo-obstruction controls.<BR><B>UNASSIGNED: </B>Apart from non-specific changes (e.g., muscle hypertrophy and distension-related muscularis propria necrosis), no alterations were identified by routine histopathological evaluation or electron microscopy. Immunohistochemistry with antibodies against a battery of smooth muscle proteins, including MYH11, revealed indistinguishable patterns of immunoreactivity in the muscularis propria of both patients and controls.<BR><B>UNASSIGNED: </B>Myopathic morphological or immunohistochemical changes may not be present in intestinal specimens from patients with MYH11-variant visceral myopathy. Molecular genetic studies should be considered for patients with chronic intestinal pseudo-obstruction and normal or non-specific pathology findings.