Surgical pathology of the appendix

Acute appendicitis Chronic appendicitis Tumors of the appendix

Appendix

Functions

– not clear in humans - it may have a significance in immune defense – abundance of lymphoid follicles - removal of the appendix may be a cause for an increase in colonic cancer incidence - not supported by controlled studies - endocrine function

“Normal” Anatomy

Typical position

2.5 cm bellow the ileo-cecal valve (base of appendix) the only fix region – important when trying to find the appendix Taeniae converge at the base of the appendix 84% free mobile in any possible location 16% fixed retrocecal

Acute apendicitis

Essentials of diagnosis

 Abdominal pain  Anorexia, nausea, vomiting  Localized abdominal tenderness  Low grade fever  Leukocytosis

General considerations

= acute inflammation of the appendix wall that starts in the mucosa and may extend to adjacent organs 70% of cases present obstruction of the proximal lumen:  Fibrous bands, fecaliths, foreign bodies  Tumors, parasites, lymphoid hyperplasia  External compression Inflammation starts in the mucosa with ulcerations and secondary bacterial infection

Close tube

Blood supply affected as disease progresses

 Infection in the wall  Increased pressure Puss formation inside the lumen Wall destruction: gangrene + perforation Bacterial peritonitis may be limited by adhesions (plastic peritonitis)

Clinical findings

Protean manifestation: may mimic a variety of conditions Progression of symptoms is essential

Clinical findings

Onset: vague abdominal discomfort Followed:  Nausea, anorexia, indigestion  Vomiting  Pain, mild, localized in the epigastrum Pain: localized in RLQ +  Pain or discomfort (moving, walking, coughing)

Examination

At this moment:  Tenderness on coughing, localized in RLQ  Localized tenderness on palpation  Slight muscular rigidity  Rebound tenderness referred to the same area  Rectal and pelvic examination NORMAL  Low fever (<38 degrees)

Examination – retrocecal appendicitis

Poorly localized pain (retrocecal position – protected from the abdominal wall) No discomfort on coughing, walking etc.

Diarrhea Urinary symptoms (hematuria, urinary frequency) Pain in the flank – tenderness on one finger examination

Examination – pelvic appendicitis

May simulate gastroenteritis Nausea, vomiting and diarrhea are more prominent (adjacent appendix to pelvic colon) Negative abdominal examination IMPORTANT – repeated pelvic (rectal) examination

Aberrant positions

Left side appendix – confusion with diverticulitis (malrotation) RUQ – cecum in abnormal position may mimic cholecystitis or perforated duodenal ulcer Normal cecum – long appendix – anything is possible

Lab workup

High leukocyte count: average 15.000/ μl, 90% more the 10.000 with more then 75% neutrophils.

 10% have normal formula Urinalysis typically normal, few leukocytes or eritrocytes. Retrocecal or pelvic – special attention

X-Ray findings

Plain X-Ray films are usually not contributory  Air-fluid levels or isolated ileus  Fecaliths  Free air in the peritoneum  Signs of peritonitis

CT scan

Ultrasound scan

Appendicitis in pregnancy

Same frequency as in non-pregnant Difficult diagnosis  High position of the appendix  All usual signs are present  Difficult to interpret leukocytosis Appendectomy is mandatory and urgent

Differential diagnosis

Differential diagnosis

Difficult in young and elderly – highest incidence of perforation High incidence of false positive appendicitis: women 20-40 PID and other genital conditions

Differential diagnosis

Local inflammatory conditions (enterocolitis, urinary infections, urinary stones, pelvic inflammatory disease) Distant digestive diseases (compliacted duodenal ulcer, billiary stones) Distant non-digestive diseases (penumonia, myocardial infarction, porphyria, lead poisoning)

Complications

PERFORATION  More severe pain  Fever >38  Typically in the first 12 hours  In 50% of patients the appendix is perforated at the time of diagnosis

Complications

PERITONITIS Localized – microscopic perforation     Increased tenderness, rigidity Abdominal distension Ileus Fever high and toxicity  Douglas pouch very sensible Generalized – classic presentation

Complications

APPENDICEAL ABSCESS (appendiceal mass)  Localized peritonitis  Walled off by peritoneum  Symptoms of appendicitis + mass in RLQ  US + CT characteristical

Complications

APPENDICEAL ABSCESS  Treatment: ATB + diet low in residue  Drainage of abscess +/- appendectomy  Postponed appendectomy 8-12 weeks Differential diagnosis:  Carcinoma of the cecum  Tumors of the appendix  Genital pathology

Complications

Pylephlebitis: suppurative thrombophlebitis of pportal vein  Chills, high fever, jaundice + hepatic abscess formation.

 Serious septic problems CT scan + US: thrombosis and gas in portal system Treatment: ATB + surgery urgent

Treatment

CHRONIC APPENDICITIS

Chronic abdominal pain

In the RLQ Possible recurrent attack of acute appendicitis Other problems Many do not consider chronic appendicitis a reality

Chronic appendicitis

= chronic inflammation in the wall due to multiple acute attacks

Pathology

– retractions of appendix and mesoappendix and adhesions

Examination

– dispepsia + pain

Workup – to exclude another pathology Tratament

– appendectomy - debatable

Tumors of the appendix

Classification

Benign – fibroma - leyomioma - lypoma Malignant – carcinoma Bordeline - carcinoid - mucocele

Benign tumors

Very rare Occasionally may obstruct the lumen and cause acute apendicitis May arise as a mass in RLQ

Carcinoma

Rare and never diagnosed preoperatively Most typical presents as acute appendicitis or RLQ abscess Prognosis: bad – 10% wide spread MTS at time of diagnosis. Rapid lymph node spread and local spread through peritoneal cavity (ovary) Treatment: right hemicolectomy + lymph node dissection

Carcinoid tumor

The most common location of carcinoid in the digestive tract Slow growth (<2 cm) and rarely MTS. 3% MTS in lymph nodes Carcinoid sdr: attacks of vasodilation, diarrhea, abdominal colical pain, tachicardia, hipotension

MTS

Examination: RLQ pain + mass

Carcinoid

Lab workup:  Urinary 5HIA  US, CT, arteriography, bronchoscopy Treatment:  Appendectomy   Right hemicolectomy (>2cm, invasion of cecum, invasion mesoappendix, nodes) MTS – enucleation (<4) +/or chemotherapy

Mucocele

Not true tumors:  Chronic distension of the appendix plus continuous mucus secretion.   Flattened epithelial cells Cystadenoma – columnar epithelium (low grade adenocarcinoma). Do not infiltrate the wall and do not produce MTS Clinical examination:  RLQ discomfort  Mass  Rupture in peritoneum: pseudomixoma peritonei

Mucocele

Treatment: appendectomy

MUCINOUS CHIST-ADENOMA - APENDICULAR