Endocrine—Carcinoid
Concept
Malignant neuroendocrine tumor. Usually asymptomatic unless outside of GI tract: bronchus, rectum, mets to liver so that hormones elaborated can bypass the portal system.
Symptoms of flushing and diarrhea from excess blood serotonin level.
Way Question May be Asked?
“31 y/o male undergoes a laparoscopic appendectomy for acute appendicitis and the pathology comes back with a 2.1 cm carcinoid at the base of the appendix. What do you do?”
How to Answer?
Treatment depends on three factors:
(1) Size (2 cm is the key—some text say 1.5 cm) (2) Site (appendix, rectum, duodenum)
(3) Pathology (depth of invasion) Appendix—appendectomy okay unless
(1) More than 2 cm
(2) Involves base of the appendix (3) Involves appendiceal fat (4) Involves lymph nodes
Then right hemicolectomy is appropriate post-op treat- ment.
Rectum—local excision okay unless (1) Greater than 2 cm
(2) Invasion of muscular coat (3) Local recurrence
(4) Fix to surrounding tissue
Then, APR is appropriate post-op treatment.
Small bowel—wide local excision with mesenteric lymph nodes
Duodenum—treat like rectum with local excision unless tumor is > 2 cm, involves muscular coat, or cannot be adequately excised (Whipple resection then appropriate)
Debulking surgery appropriate with liver mets and lymph node involvement
Multiple wedge resections or lobectomy appropriate for liver mets
Selective embolization also a treatment for liver mets For symptomatic carcinoid tumors, somatostatin is
drug of choice.
Chemo streptozotocin in advanced cases with little help Remember adequate pre-op work-up as right sided
valvular fibrosis occurs in late disease Measurement 5’HIAA in 24 h urine
Octreotide scan to localize neuroendocrine tumors Carcinoid crisis may occur shortly after inducing anes-
thesia with:
Cardiac arrhythmias Labile blood pressure Generalized flushing Treatment with octreotide
Multiple synchronous tumors in 1/3 pts so full ex lap Many pts with small intestinal carcinoid present as SBO
in pt without other risk factors In carcinoid syndrome:
Flushing may be brought on by emotional stress or meals
Diarrhea unrelated to flushing
Common Curveballs
Carcinoid will be less than 2 cm but invade appendiceal fat
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Pt will ask for other options besides right hemicolec- tomy for 1 cm carcinoid at appendiceal base
Pt will have carcinoid syndrome with carcinoid tumor you can’t locate
Pt will present with episodic flushing and diarrhea Pt will have liver metastases and may require lobectomy
to fully debulk
Pt will have ampullary carcinoid requiring Whipple to fully excise
Pt will have carcinoid crisis intra-op
Pt will present with SBO secondary to tumor, path = small bowel carcinoid
Asked about use of medication to treat carcinoid syndrome
Strikeouts
Forgetting full physical exam—pt will have rectal carcinoid
Forgetting adequate pre-op w/u in pt with carcinoid syndrome—pt will have tricuspid or pulmonic valvu- lar disease
Forgetting the characteristics that determine surgical treatment of carcinoid tumors
Failing to perform appropriate cancer operation with resection of accompanying mesentery/lymph nodes Failing to perform full ex lap to r/o other carcinoid
tumors in small bowel
Failing to recognize the carcinoid syndrome when present
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