Incidental findings and Incidentalomas – NET or NOT

During my diagnostics, I presented to my general practitioner as someone with symptoms of iron deficiency anaemia with some weight loss (not a lot but some). The GP at this point had no alternative but to refer me to secondary care where they had the tools to investigate further – e.g. imaging and endoscopies. The use of laboratory testing and imaging devices are there to not only back up the a doctor’s clinical hypotheses but also to test them, i.e. these laboratory tests and imaging checks may lead to others.

Differential checks are not misdiagnoses, they are part of the investigation. The initial referral is not a misdiagnosis as many people in our community might wrongly claim, but it is standard diagnostic methods used across the globe. Seeing more than one doctor is pretty common when you look at diagnostics in the round. When you visit your healthcare provider with symptoms, they will begin a process to diagnose your condition. Since there are a lot of different conditions that often share similar symptoms, your provider should consider the differential diagnoses, which is a list of possible conditions that could cause your symptoms. Any of the differential diagnoses is not your official diagnosis, but a step before determining what could cause your symptoms but still lacks evidence to confirm. I accept that thoroughness is a highly subjective approach based on many factors.

Body awareness after diagnosis. After my formal diagnosis, I was more aware of my body than I was previously, common amongst cancer patients. I once mentioned to my Oncologist that I thought my right clavicle bone was protruding much further out than my left one. He looked at a recent scan, carried out a physical examination and said this was nothing to worry about. He reminded me about something I already knew, my own awareness of my body was greatly increased because of the experience of being diagnosed with a life threatening disease.

Incidental findings. Many things are actually very common in the general population. When you look at epidemiological data about many conditions, one things that frequently stands out is that many common symptoms and common conditions are significantly more prevalent than anything found in the NET world. Some things inside your body are actually pretty common in the general population and any are discovered incidentally when a person is subjected to endoscopies and imaging which is checking for something else. I have written about many of them and wanted to consolidate the main ones below.

Knowledge is power. I took my doctor’s advice about body awareness but began to study a bit more, mainly via my blog. However, after I set up my own private group, I began to see trends in many things I had gone through myself. This motivated me further as I studied many differential possibilities of common issues found by people in my group, particularly as they were diagnosed and had to undergo many checks. It’s really easy to encourage people to believe what they think via empathy, but I also believe it’s important and responsible to offer a wider response, if only to generate questions to ask of a healthcare professional.

Finally. To quote a famous NET specialist:

“even NET patients get regular issues”

Incidental Findings including ‘Incidentalomas’

I mentioned above my experience of suddenly becoming aware of my body and what it was doing. The slightest thing was almost automatically aligned with the NET. I also discovered something called an ‘Incidentaloma’ which is related to imaging (scans and scopes). An incidentaloma is a term used in radiology to describe an unexpected mass or lesion discovered during imaging performed for unrelated reasons. These findings are typically asymptomatic and of uncertain clinical significance at the time of discovery, often presenting a diagnostic dilemma: balancing the risks of over-investigation and overtreatment against the possibility of missing a significant pathology. Some are so common that there are guidelines avaiulable for doctors.

One thing that can be quite worrisome for a NET patient is that many of these incidentalomas can be found in several endocrine organs where NETs are known to be found (commonly or uncommonly). Not all incidentalomas require biopsy or surgery; many are monitored. I researched many of these below and I’m still adding.

Of course it’s not just abnormalities found on imaging, some common illnesses can also be worrisome.

Lung nodules

My first diagnostic CT (possibly my first ever CT from memory) pointed out a 2mm lung nodule. I was told it was benign and nothing to worry about. Nontheless, as I was on long term surveillance, it would be watched. I was happy with that plan. Then I discovered through educating myself that these are very common in the general population. That nodule has not changed since diagnosis in 2010.

Read more about Lung Nodules here or click on the picture below.

Thyroid issues

My thyroid has had quite a bit of attention. Firstly, and 3 years after diagnosis, the mention of a “thyroid lesion”. Eventually a biopsy confirmed this was not NET, although it took 3 fine needle and 1 core biopsy to get enough tissue. I then educated myself to find these things are also pretty common in the general population. Moreover, I also found out that metastases to the thyroid is quite rare with 98% of thyroid tumours being a primary site. This continues to be watch and wait but later on, my thyroid panel picked up mildly elevated thyroid hormones and I was prescribed a supplement. I also learned that somatostatin analogues can affect levels. Read more by clicking here or on the picture below.

Other thyroid posts you may find useful:

Liver lesions and cysts

I remember a mention of “simple liver cysts” on my diagnostic CT scan and subsequent scans. I don’t see it mentioned since surgery, so I guess it was removed as part of my right hepatectomy and a metastasectomy.

Benign liver cysts, sometimes called simple cysts, are the most common form of liver cyst. Healthcare providers estimate that 15% to 18% of people in the United States and 5% to 10% of people worldwide have liver cysts. Most are congenital.

Click here or on the picture below to read more.

Kidney cysts

In the medical world, the term “renal” refers to the kidney. When I was diagnosed and subjected to several CT scans, each one noted the existence of a renal cyst. I was told it was nothing to worry about although I did find the size worrying on the basis I didn’t think the average kidney could be so big to house a 55mm cyst! That was back in 2010 and they still mention that cyst today, but it no longer worries me. Like many cysts in the human body, these incidental findings on diagnosis are pretty common. Read more about Renal cysts by clicking here or on the picture below.

Pancreatic cysts

This is another topic I see in my group. The pancreas is a difficult organ to reach and a difficult organ to manage by surgery. The incidence rate rises with age and is a lot higher than the incidence rate for pancreatic NET. The surgical risks are higher than many other NET operations. Clearly pancreatic cysts which are mostly benign issues and most are unrelated to NET. Nonetheless, the risk of a pancreatic cyst being NET needs careful checking. Read more by clicking here or on the picture below.

Histamine issues – NET or NOT – incidental findings can happen with hormone issues too

Another curious area because histamine issues can be from multiple sources plus one major NET Centre of Excellence recently stated that the involvement of Histamine in carcinoid syndrome does not have enough evidence (see Histamine blog below). One major NET specialist in USA stated that he had not seen any cases of histamine in his large practice and that it is not something tested due to it being a tricky thing to test. I assume he meant the following nuance:

When histamine is elevated in blood or urine, pinpointing the cause isn’t straightforward because histamine is a reactive mediator with a short half-life and multiple triggers. i.e. Blood or urine histamine levels can indicate that histamine release has occurred, but they don’t specify the trigger. The trigger could be many things because histamine is released by mast cells and basophils in response to:

• Allergens (e.g. pollen, food proteins)
• Physical stimuli (heat, cold, pressure)
• Infections
• Stress
• Certain medications
• Endogenous dysregulation (e.g. mast cell activation syndrome, histamine intolerance).

Testing histamine levels

Blood test:

Can measure histamine and the enzyme diamine oxidase (DAO), which is responsible for breaking down histamine in the body.

24-hour urine test:

Often measures N-methylhistamine, a histamine metabolite, to provide a picture of histamine production over a longer period.

Diagnosis of histamine intolerance:

A blood test for DAO activity can be useful, as low DAO activity can indicate histamine intolerance.

Diagnosis of other conditions:

Histamine and tryptase tests are sometimes requested for conditions like mastocytosis or mast cell activation disorder.

What to expect

Preparation: You may be advised to avoid a low-histamine diet before testing for inaccurate results.
Procedure: For a blood test, a blood sample is collected. For a urine test, you may need to collect all urine over a 24-hour period.
Results: A lab will analyse the sample and provide a report that may include your DAO levels, histamine levels, or other findings.

Important considerations

- Histamine intolerance: If you have a histamine intolerance, your symptoms may be caused by the body’s inability to break down histamine, which can be assessed with a DAO test.
- Accuracy: Results can be affected if you are on a low-histamine diet before testing.
- Professional guidance: It’s important to discuss the results with a healthcare professional to get an accurate diagnosis and treatment plan.
  Click graphic to read more

Physiological uptake and pathological processes – incidental findings from scans

Another area of confusion and mystery in the NET world, is the output of Somatostatin Receptor (SSTR) based scans, particularly SSTR PET (e.g. Ga68, Cu64). Just because something “lights up”, it does not mean this is NET. This can lead to enormous anxiety for a patient, particularly in healthcare systems where the patient sees the output prior to the specialist appointment to explain the results.

It’s important to have some understanding of the physiologic and other pathologic processes in which cellular expression of SSTR can lead to interpretive error. Click here or on the picture below to read more. There’s also a section on FDG PET which can have the same effect as SSTR PETs.

**Incidental Findings in SSTR PET –** Click picture to read more

Work in Progress – Adrenal Incidentalomas

to follow

Placeholder for yet another common incidental finding

to follow

Disclaimer

I am not a doctor or any form of medical professional, practitioner or counsellor. None of the information on my website, or linked to my website(s), or conveyed by me on any social media or presentation, should be interpreted as medical advice given or advised by me.

Neither should any post or comment made by a follower or member of my private group be assumed to be medical advice, even if that person is a healthcare professional. Some content may be generated by AI which can sometimes be misinterpreted. Please check any references attached.

Please also note that mention of a clinical service, trial/study or therapy does not constitute an endorsement of that service, trial/study or therapy by Ronny Allan, the information is provided for education and awareness purposes and/or related to Ronny Allan’s own patient experience. This element of the disclaimer includes any complementary medicine, non-prescription over the counter drugs and supplements such as vitamins and minerals.