You have recieved your COVID19 immunizations and have returned to your outpatient
practice. Your are examining a 62-year-old woman who is referred to you to determine
the cause of her hepatomegaly. Shown below is a picture of the paient taken before
your abdominal exam (left panel) and a picture of the patient taken while you are
examining her liver (right panel).
What is your diagnosis, what lab test(s) would you order to confirm you suspicions,
and what treatment, if any, do you recommend?
DIAGNOSIS: Carcinoid syndrome. Carcinoid (neuroendocrine) tumors (NETs) create a relatively
rare group of neoplasms with an incidence of about 2.5 to 5.0 cases per 100,000 persons.
Most NETs are located in the gastrointestinal tract, particularly the proximal colon
and distal small bowel, although they may arise in other tissues including the lungs,
bone, ovaries and retroperitoneum.
Roughly 30-40% of patients with NETs develop the carcinoid syndrome (CS). CS is
usually due to the transhepatic passage of vasoactive amines, most particularly serotonin
(5-hydroxytryptamine, 5-HT). CS signs and symptoms may include flushing, bronchospasm,
cyanosis, diarrhea, abdominal cramping, hypotension, telangiectasia, and pellegra
(note the presented case has cheilosis, a sign of niacin deficiency). The syndome
occurs most commonly when NETs metastasize to the liver although roughly 5% of cases
occur in subjects with other sites of involvement and in the absence of hepatic metastases.
About 20-30% of patients with the carcinoid syndrome develop carcinoid heart disease.(CHD)
A number of mediators in addition to 5-HT have been implicated as causual factors
in CHD; these include bradykinin, histamine, neurokinin A, neuropeptide K, prostaglandins,
substance P and transforming growth factor. As might be expected, CHD affects the
right heart predominantly, causing fibrosis of valve leaflets and fused and shortened
chordae. The left heart may be involved, causing similar anatomical deformities in
the aortic and mitral valves.
Treatment of CS may include cytoreduction or transcatheter embolization of hepatic
metastasis and/or the use of somatostatin analogue drugs such as octreotide. Radiolabelled
octreotide may be used to detect these tumors.