Part two - appendix

Question 1

Define pseudomyxoma peritonei

Answer 1

Diffuse collections of gelatinous material in the abdomen and pelvis and mucinous implants on the peritoneal surface.

Initially intrapertioneal mucinous dissemination from rupture of a benign cystadenoma but now encompasses mucus-producing adenocarcinomas of appendix, small bowel, colon, breast, pancreas, stomach, bile ducts, gallbladder, tubes and ovaries

Question 2

Classify pseudomyxoma peritonei

Answer 2

DPAM = disseminated peritoneal adenomucinosis
- copious mucinous ascites
- benign mucinous epithelium
- secondary to ruptured appendiceal mucinous cystadenoma
PMCA-I = as below with intermediate features
PMCA = peritoneal mucinous carcinomatosis
- Abundant peritoneal mucinous tumour
- Adenocarcinoma
- Worse prognosis +++

Question 3

What is an appendiceal mucocele?

Answer 3

A rare group of lesions characterised by a distended, mucus-filled appendix

Question 4

What is the differential of an appendix mucocele?

Answer 4

Intraluminal
- faecolith
Intramural
- stricture
- mucosal hyperplasia
- cyst adenoma (may be mucinous)
- cyst adenocarcinoma (may be mucinous)
- carcinoid
- GIST
- lymphoma
Extraluminal
- caecal tumours
- endometriosis

Question 5

Surgical treatment of appendiceal carcinoid

Answer 5

simple appendicectomy
>2cm –> right hemicolectomy

1-2cm right hemi any of these high risk features present:

• Mesoappendix invasion
• Serosa involvement
• LVI
• High Ki67 index (>2%)
• Positive LNs in appendicectomy specimen
• Mixed histo - goblet cell or adenocarcinoid
• Involved or unclear margins