MCQs on Appendicitis and appendix location are common in exams. Clinical signs and symptoms, Ultrasound findings of appendicitis and cancer of appendix are other common questions.
Positions of Appendix
1. Retrocecal - Posterior to the cecum and lower part of the ascending colon.
2. Pelvic /Descending Descending over the pelvic brim
3. Subcecal Below the cecum
4. Preileal Anterior to the terminal ileum and in relation to the anterior abdominal wall
5. Postileal Posterior to the terminal ileum
Multiple Choice Question in Appendix
Q1. Which of the following is not a typical symptom of appendicitis?
Q2. Least common position of appendix is
Q3. Most Common malignancy of appendix is?
a) Carcinoid Tumor
c) Squmaous Cell carcinoma
d) MIxed Cellularity
Q4. All are features of Acute Appendicitis on Ultrasound examination except?
a) A compressible blind ending tube
b) Diameter of more than 7 mm
c) Loss of submucosal echogenicity
Q5. What is not true as differential diagnosis for appendicits in the elderly
a) Adenocarcinoma appendix
Q6. Regarding Neuroendocrine tumors of appendix which is not true?
A) The prognosis of tumor in appendix is better than that at other sites.
B) For tumors less than 1 cm the 5 year survival rate approaches 95%
C) Male and female are equally affected
D) Distal metastasis occcur in about 1 % patients if tumor is more than 2cm in size
Q7 What is not true regarding hyperplastic polyps in appendix
A) Appendiceal polyp is a rare but known entity
B) It predisposes the appendix to the risk of adenocarcinoma like polyps anywhere in GI tract
C) Patients can present as acute appendicitis
D) If appendix with hyperplastic polyps is completely removed there is no need for screening of rest of the Colo- rectum
Answers in appendix MCQ
Symptoms of Appendictis
Shifting pain from periumbilicus to Right iliac fossa is the most definite symptom of appendictis. Other common symptoms are anorexia, nausea, vomiting and fever. Some atypical symptoms include haematuria (tip of appendix irritating urinary baldder) , diarrhea (in pelvic appendicitis), small bowel obstruction and even chest pain. Hematochezia (bleeding in stools in not a symptom of appendicitis)
There is excessive debate regarding the exact incidence of various positions of appendix. Although the position of the base is constant, there are wide variation in the position of the tip of appendix. Most common position of appendix is retrocaecal (65) % followed by Pelvic (20%). Other common positions are preileal and post ileal. Retroileal position of appendix is the least common. It is seen in only 0.2%.
Tip: Appendix location depends on tip of the appendix
Carcinoid tumor is the most common tumor of the appendix. All specimens sent for HPE after appendicectomy show a .3% and .9% incidence of carcinoid tumors. .08% to .1% have adenocarcinoma.
Sabiston 20th edition pg 1308
All these are true
Altough adenocarcinoma of appendix can present as appendicitis, it is never kept as a differential diagnosis when appendicits is contemplated.
The average age at diagnosis is approximately 20 years younger than for NETs from other sites. Women predominate, with a male-to-female ratio of 1 : 3.
The prognosis for patients with conventional appendiceal NETs is better than that for all other anatomic sites. The majority of appendiceal NETs are localized to the appendix at the time of diagnosis. Eighty percent are smaller than 1 cm in diameter, and demonstrate a 5-year survival rate greater than 95%. Lymph node metastasis to regional nodes occurs in approximately 4% of all appendiceal ECC NETs, and this is usually in tumors larger than 2 cm. Distant metastasis occurs in about 1% of cases, once again usually only in tumors larger than 2 cm.
Hyperplastic polyps are rare in the appendix. Diffuse hyperplasia is more common but some of these lesions are better classified as sessile serrated adenomas. Hyperplastic lesions are often incidental findings, although they can be associated with acute appendicitis. They are significantly associated with adenocarcinoma elsewhere in the large intestine, and the finding of mucosal hyperplasia in an appendectomy is an indication for further investigations to exclude colorectal neoplasia.
McBurney's point, the junction of the lateral and middle thirds of the line that joins the right anterior superior iliac spine to the umbilicus, is used as a surface marking for the base of the appendix. The three teniae coli converge at the tip of the cecum to form the continuous longitudinal muscle layer of the appendix. The base of the appendix can be located by tracing the anterior taenia coli to the tip of the cecum. The ileocecal fold of peritoneum, which connects the terminal 2.5 cm of ileum to the cecum, can also be used to determine appendix location. A short, triangular mesoappendix extends along the length of the appendix and connects it to the lower portion of the mesentery of the ileum.
Pathophysiology of Acute Appendicitis
The most commonly accepted theory of the pathogenesis of appendicitis is that it results from obstruction followed by infection. The lumen of the appendix becomes obstructed by hyperplasia of submucosal lymphoid follicles, a fecalith, tumor, or other pathologic condition. Once the lumen of the appendix is obstructed, the sequence of events leading to acute appendicitis is probably as follows:
Mucus acumulates in the lumen of appendix, The pressure inside increases, Mucus gets converted into pus, Obstruction to lymphatics, edema, mucus ulcers and finally perforation.
Questions on Appendicitis asked in USMLE
1. Why does right testis elevate in appendicitis ? Due to irritation of genitofemoral nerve which causes contraction of cremaster. The nerve reuns on psoas major where it is susceptible to be irritated by inflamed appendix.
2. Anorexia and vomiting generally precede the onset of classical pain
3.Classical triad includes anorexia, pain fever
4. At exploration normal looking appendix should still be removed to avoid confusion in future.