Myofibrotic malformation vessels: unique angiodysplasia toward the progression of hemorrhoidal disease

Sheng-Long Li,1,* Fang-Yan Jing,1–3,* Li-Li Ma,2,3 Li-Li Guo,2,3 Feng Na,2,3 Sheng-Li An,4 Yan Ye,5 Jun-Ming Yang,1 Ming Bao,1 Dong Kang,1 Xiao-Lan Sun,1 Yong-Jian Deng2,3 1Department of Anorectal Surgery, 2Department of Pathology, Nanfang Hospital, 3Department of Pathology, School of Basic Medical Sciences, 4Department of Biostatistics, Southern Medical University, 5Department of General Surgery, Xintang Hospital, Zengcheng, Guangzhou, People’s Republic of China *These authors contributed equally to this work Background: The etiology and pathogenesis of hemorrhoids is unclear, although hemorrhoids are a worldwide disease in men and women, with peak prevalence at 45–65 years of age. Hemorrhoidal cushions as the anal venous plexi are normal anatomical structures from infancy. This study attempts to reveal the angiodysplasia and other pathological changes in association with different degrees of symptomatic hemorrhoids.Materials and methods: A total of 281 patients with internal hemorrhoids from degree I to IV underwent hemorrhoidectomy. The vascular changes were analyzed by microscopic assessment and software analysis, with Masson’s trichrome, CD34, and smooth muscle actin.Results: The hemorrhoidal tissues exhibited abnormal vessels in the mucosae and submucosae that we termed them as myofibrotic malformation vessels (MMVs). MMVs are not ascribed to arteries or veins because they exhibit enlarged and tortuous lumens with smooth muscle dysplasia and fibrotic deposition in the walls without overlying mucosal ulceration. The muscularis mucosae also showed smooth muscle dysplasia and fibrosis, even if it were interrupted by the intruding MMVs. The statistical data indicated that the severity of all the changes correlate positively with the progression of hemorrhoids (P