Surgical Pathology of Primary Intestinal Myopathy

Microscopic alterations indicative of primary intestinal myopathy must be distinguished from nonspecific findings associated with chronic distension, surgical procurement, or preanalytic tissue processing. Most histopathologically recognizable forms of primary intestinal myopathy can be grouped as either structural alterations of the muscularis propria or degenerative leiomyopathies. Some histopathologic findings correlate with specific types of primary intestinal myopathy, but biopsies or resections from many patients with pathogenic variants in genes that encode smooth muscle contractile proteins show no diagnostic alterations. In some situations, an invasive procedure to obtain tissue for histopathologic evaluation has limited utility and molecular genetic testing may be a superior initial diagnostic approach.