Etiopathology 2 (Hirschsprung´s Disease)

obst_2a_n.jpg and obst_2b_n.jpg: Histological preparations of the superficial rectal wall with acetylcholinesterase staining for the identification of acetylcholinesterase-positive nerve fibers, and hemalaun staining for the depiction of the endothelial cells in a normal ( obst_2a_n.jpg) and an aganglionic rectum ( obst_2b_n.jpg). obst_2a_n.jpg: Normal rectum with slightly brownish stained acetylcholinesterase-positive parasympathetic nerve fibers in the submucosa. Using the described staining technique, there is a nomal superficial rectal wall. obst_2b_n.jpg: Pathological rectum with an intense brownish discoloration of the acetylcholinesterase-positive parasympathetic nerve fibers concerning the extension and density. This pattern of staining of the superficial rectal wall is characeristic for Hirschsprung's disease; the intensive staining is due to a hyperplasia of the submucous and peripheral parasympathetical nerve fibers typical for Hirschsprung's disease. obst_2c_n.jpg and obst_2d_n.jpg: Histological preparations of the superficial rectal wall; acteylcholinesterase staining for the identification of the acetylcholinesterase-positive nerve fibers in a normal and in a pathological rectum. In the absence of hemalaun staining the more intensive staining of the acetylcholinesterase-positive nerve fibers is more distinctly recognizable in obst_2d_n.jpg when compared with obst_2c_n.jpg; likewise, the extension of these fibers in the mucosa which is missing in obst_2c_n.jpg. The advantage of this technique is that these mucosal biopsies can be obtained without pain with suction-biopsy from the anus in an out-patient procedure. In addition, the danger of an intestinal wall perforation is minimal in comparison to surgically obtained biopsies. The disadvantage may be the difficulties to obtain sufficiently deep biopsies including the submucosa to exclude a dysganglionosis, and the reliability of the findings in the neonatal period with possibly false negative findings under the age of 3 weeks. Because both pathological preparations are from the same patient, the transition zone must lie in the rectum between 3 and 12 cm from the anus (compare types of Hirschsprung's disease).