Images from the NET clinic...
Working in the NET clinic is often humbling... Tumors do not read textbooks and sometimes, things just do not make sense but yet are happening right in front of you. As I often say, every patient with NET is unique (of course, every patient with cancer regardless of cancer type is unique...) with their own clinical presentation.
This patient below has metastatic lung NET, indolent, producing very large amounts of serotonin but with no diarrhea or flushing (serotonin does not cause flushing by the way but does cause diarrhea) so essentially asymptomatic in terms of typical carcinoid syndrome. This patient however has carcinoid heart disease with severe tricuspid and pulmonary valve regurgitation. Interestingly, there is no lower extremity edema but there is pulsatile hepatomegaly (a classic finding), both systolic and diastolic murmur, elevated JVP but not a trace of lower extremity edema.
Below you can see evidence of hepatic venous congestion in the venous phase of the CT with what sometimes is called nutmeg liver. That lobular pattern is not seen on the arterial phase or on the recent gadoxetate enhanced delayed MRI imaging.
I just thought I should share that carcinoid syndrome can present in very atypical ways without the cardinal symptoms of diarrhea and flushing. In this case, carcinoid heart disease is the only manifestation of the syndrome.