Rare Variant Hirschsprung Disease Presenting as Large Bowel Obstruction in Adulthood: Hypoganglionosis in the Anorectal Canal

Hirschsprung disease (HD) is a congenital bowel innervation disorder characterized by the absence of ganglion cells in the neural plexus of the colorectal wall. Variant HD describes a heterogeneous group of intestinal innervation disorders in which clinical presentation resembles HD despite the presence of ganglion cells seen in rectal biopsies. We present the first reported case of a rare variant HD, hypoganglionosis isolated in the anorectal canal, diagnosed in an adult who presented with a long history of constipation and treated with proctosigmoidectomy with coloanal anastomosis. Histopathology showed rare ganglion cells isolated in the anorectal canal.