Appendicitis: Pathology

Appendicitis is a pathology linked to the appendix. As with all other pathology, appendicitis is a condition with a specific definition, symptoms, and appearance. The appendix is a pouch-like tissue that extends from the large intestine and is approximately 3.5 inches long. The appendix is a curious body part because although it is not vital to human survival, it can cause death. According the the Merriam-Webster Medical Dictionary, Appendicitis is an inflammation of the vermiform appendix; also called epityphlitis. Appendicitis occurs when the appendix becomes blocked by either stool, a foreign body, cancer or an infection (in which case the appendix swells in response to any bodily infection.) The main clinical signs and symptoms of Appendicitis are an aching abdominal pain that begins around the navel and becomes sharper over several hours.

Another sign is rebound tenderness to applied pressure to the lower right sector of the abdomen; the location of the appendix. With that being said, the locus of pain may vary depending on age and the position of the appendix; especially in young children and pregnant women. Another symptom is the inability to sit and heightened pain when walking, coughing, or other movement. A few other symptoms are as follows: nausea, vomiting, loss of appetite, fever, constipation, inability to pass gas, diarrhea, abdominal swelling. The usual treatment for appendicitis is surgery and removal of the appendix called an Appendectomy. If the appendix has burst an abscess can form around it in which case the abscess must be drained through a tube before the appendectomy.

“The normal appendix presents as a small, easily compressible, concentrically layered, mobile, blindending, sausage-like structure. The diameter is usually less than 7 mm, but is incidentally large. The normal appendix is mobile, may have a collapsed lumen, but also may contain air or some fecal material, and rarely a little fluid. Power Doppler reveals scarce or no vascular signal and there is no hyperechoic, noncompressible inflamed fat around the appendix. The typical appearance of an inflamed appendix is that of a concentrically layered, noncompressible sausage-like structure demonstrated in a fixed position at the site of maximum tenderness. The average maximum diameter is 9 mm with a variation from 7 to 17 mm. Six to 12 hours after the onset of symptoms, the inflammation progresses to the adjacent fat of the mesoappendix, which becomes larger, more hyperechoic, and less compressible.

Later on, this fatty tissue tends to increase in volume around the appendix: this represents mesentery and omentum, which have migrated toward the appendix in an attempt to wall-off the imminent perforation. Vascularization of the appendiceal wall is either markedly increased or absent because of high intraluminal pressure with concomitant ischemic necrosis; however, there is always increased vascularization in the directly surrounding fatty tissue.” “USG demonstrates a fluid filled dilated appendix measuring more than 6mm in diameter. Mild increase in echogenicity is seen in the periappendiceal region and may suggest inflammation. The findings of appendicitis was confirmed on surgery and histopathology.”