Neuroendocrine Tumors- A Complete Guide to Understand the Condition & Its Coding

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With incidence rates increasing markedly over the past fifteen years more and more people are being diagnosed with cancer. Accounting for a small fraction of the number of new cancer cases, more than 12,000 Neuroendocrine Tumors (NET) cases are reported annually in the United States.

I was diagnosed with an incurable blood cancer called multiple myeloma in early 1994. MM is a rare cancer at about 33,000 diagnoses annually. NET’s annual diagnoses are about a third of that.

A cancer diagnosis can be a challenging, life- changing event. Your job as the patient or caregiver is to learn as much about your diagnosis as you can, in as short a time as possible. Only after learning about your diagnosis can you make the best decisions possible- for you and your loved ones.

To lean about evidence-based but non-toxic, non-conventional cancer therapies, scroll down the page, post a question or a comment and I will reply to you ASAP.

Thanks and hang in there.

David Emerson

  • Cancer Survivor
  • Cancer Coach
  • Director PeopleBeatingCancer

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What Are Neuroendocrine Tumors?

A tumor develops when the cells in response to a signal from the nervous system release hormones into the blood. Or cancer that begins in specialized cells such as neuroendocrine cells is termed neuroendocrine tumors.

Where Are They Usually Found? 

Basically, it can occur anywhere in the body though, it is very rare. These cells aid in the regulation of various functions of the human body, such as reproduction, growth, and metabolism. 

Many neuroendocrine tumors mostly occur in the pancreas, lungs, rectum, small intestine, and appendix. They are distributed throughout the body. These tumors grow very quickly and some grow slowly. 

Are All These Tumors Cancerous?

‘’Yes’’ can be a brief answer to this question. 

Based on the appearance of the tumor cells examined by the microscope, pathologists describe them as either ‘’malignant’’ (cancerous) or ‘’benign’’ (non-cancerous). It cannot tell you unfortunately whether the tumor will behave aggressively and will metastasize. 

Some tumors grow and spread easily while some do not. However, you can consider all of them to be cancerous. 

Types of Neuroendocrine Tumors 

There are various types of NETs, some of them are;

  • Islet Cell Tumors (Pancreatic Neuroendocrine Tumors)

This tumor can form in the pancreas but can also typically arise outside the pancreas. 

  • Carcinoid Tumors 

They can also grow in the brain, lymph nodes, gonads (testes and ovaries), skin, and bone. These tumors mostly occur in the lungs, digestive tract, thymus, and appendix. 

  • Pheochromocytoma

It typically develops in the adrenal gland but it is a rare type and also can be formed in other parts of the human body. 

Symptoms of Neuroendocrine Tumors

It is categorized in two ways;

  • Mechanical:

In this category, the tumor pushes on another structure physically. It relates to the function of a single part of the body, like pain in a particular place and obstruction of the small bowel. 

  • Hormonal:

This involves uncontrolled blood sugar, severe gastric ulcer, and severe diarrhea that correspond improperly to treatment. Its place in the body varies depending on where the tumor formed. 

It usually does not show symptoms and signs in the first place. The signs you feel in general are whether it produces excess hormones and depends on the location of your tumor.

Some symptoms may include;

  • Losing weight without trying.
  • Pain from a growing tumor.
  • Feeling unusually tired. 

Functional tumors (that produce excess hormones) may induce:

  • Diarrhea.
  • Skin flushing.
  • Shakiness.
  • Frequent urination.
  • Vomiting.
  • Rapid pulse.
  • Sweating.
  • Nausea.
  • Headache.
  • High blood pressure.
  • Fever.
  • Dizziness.
  • Skin rash.
  • Persistent fever or night sweats.
  • Increased thirst.
  • Hoarseness or cough that does not go away.

Risk Factors

People who inherit genetic syndromes have a greater risk of neuroendocrine tumors that enhance cancer. Some risk factors are;

  • Neurofibromatosis.
  • MEN 2 (Multiple endocrine neoplasias, type 2).
  • Tuberous sclerosis.
  • MEN 1 (Multiple endocrine neoplasias, type 1).
  • Von Hippel-Lindau disease.


Its exact cause is still unknown. The neuroendocrine cells are found throughout your body. Neuroendocrine cells have traits that are alike to hormone-producing cells and nerve cells. 

There are various kinds of NETs. Some neuroendocrine tumors do not release hormones to cause symptoms (non-functional tumors). While some produce an excess hormone (functional tumors). 

When neuroendocrine cells develop then the changes in their DNA mean it mutates, that’s the phase these tumors start to form. In the cell, DNA has instructions on what the next step a cell has to follow. These adaptations command the cell to form a tumor by multiplying rapidly. 

Some tumors destroy the normal body tissues by invading the cell and start to metastasize to the other parts of the cell too. On the other hand, others take some time to grow properly. Moreover, a correct combination of adequate supportive cancer-related care therapies can assist you to handle the side effects of the disease in a better manner.


A variety of screening tests can help an oncologist to detect diseases early. Such as 

  • X-rays.
  • Biopsy.
  • Positron emission tomography (PET). 
  • Computed tomography (CT or CAT) scan.
  • Magnetic resonance imaging (MRI).
  • Molecular testing of the tumor. 
  • PET-CT scan.

Some other treatment methods include alpha-adrenergic blockers and radiation therapy. Many oncologists may perform laparoscopic surgery to eliminate the tumor.

Depending on the stage and type of the diseases some most common options for the NETs treatment are given below:

  • Medical Oncology

Depending on the treatment goals and type of NETs, some options include hormone therapy, chemotherapy, and targeted therapy. 

  • Surgery

The patients having localized NETs often take the first-line treatment by removing the primary tumor through surgery. 

  • Radiation Therapy

When the neuroendocrine tumor has spread, radiation therapy is generally recommended. Moreover, the location also makes the surgery difficult.  

  • Gastroenterology

You can reduce breathing problems and relieve pain when a gastroenterologist removes the obstructions in the gastrointestinal tract. 


You can manage this disease with various options that involve;

  • Surgery to remove the surrounding tissue/tumor.
  • Careful surveillance. 
  • Various non-surgical therapies to stop it from growing/shrinking the tumor. 

Besides, some reports suggest that in the United States the total incidence of NETs is between 5-9 million individuals. There might be a reason that these are underreported tumors due to not producing dramatic symptoms and growing slowly. Even so, various signs of tumors are due to those hormones which are secreted by tumors and can affect the whole human body. 

For oncology specialists who treat such types of life-threatening diseases, precision in coding and billing is imperative to provide quality healthcare service to patients. Oncologists can rely on an experienced medical billing company to receive correct reimbursements on time and meet their claim submission tasks efficiently. 

ICD – 10 Codes for NETs

C7A – Malignant neuroendocrine tumors.

  • C7A.0 – Malignant carcinoid tumors
  • C7A.00 – Malignant carcinoid tumor of unspecified site.
  • C7A.1 – Malignant poorly differentiated neuroendocrine tumors
  • C7A.8 – Other malignant neuroendocrine tumors.
  • C7A.01 – Malignant carcinoid tumors of the small intestine
  • C7A.010 – Malignant carcinoid tumor of the duodenum.
  • C7A.019 – Malignant carcinoid tumor of the small intestine, unspecified portion.
  • C7A.012 – Malignant carcinoid tumor of the ileum.
  • C7A.011 – Malignant carcinoid tumor of the jejunum.
  • C7A.09 – Malignant carcinoid tumors of other sites
  • C7A.090 – Malignant carcinoid tumor of the bronchus and lung.
  • C7A.092 – Malignant carcinoid tumor of the stomach.
  • C7A.091 – Malignant carcinoid tumor of the thymus.
  • C7A.093 – Malignant carcinoid tumor of the kidney.
  • C7A.095 – Malignant carcinoid tumor of the midgut, unspecified.
  • C7A.094 – Malignant carcinoid tumor of the foregut, unspecified.
  • C7A.098 – Malignant carcinoid tumors of other sites.
  • C7A.096 – Malignant carcinoid tumor of the hindgut, unspecified.
  • C7A.02 – Malignant carcinoid tumors of the appendix, large intestine, and rectum
  • C7A.021 – Malignant carcinoid tumor of the cecum.
  • C7A.020 – Malignant carcinoid tumor of the appendix.
  • C7A.023 – Malignant carcinoid tumor of the transverse colon.
  • C7A.022 – Malignant carcinoid tumor of the ascending colon.
  • C7A.029 – Malignant carcinoid tumor of the large intestine, unspecified portion.
  • C7A.025 – Malignant carcinoid tumor of the sigmoid colon.
  • C7A.024 – Malignant carcinoid tumor of the descending colon.
  • C7A.026 – Malignant carcinoid tumor of the rectum.

Similarly, oncology coding and medical billing is a time-consuming and complicated task. The screening tests, diagnosis, and procedures take a lot of time while documenting accurately by using the accurate CPT codes. 

Oncology medical billing services provided by a reputable medical billing company can help healthcare providers to focus on what matters most_ their patients.

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