TESTS and DIAGNOSIS
The diagnosis of DIPNECH is based on the presence of areas in the lungs where the bronchioles are invaded by pulmonary neuroendocrine cells (PNCs). In DIPNECH there are patches of the lungs which are normal, and other patches where the bronchioles are affected. In the past, the diagnosis was usually made when a tumor was seen on a regular X-ray, and a biopsy showed the tumor to be a carcinoid. Special staining of the tissues around the carcinoid tumor would reveal the presence of PNCs in the bronchioles. In the past five years or so, a new type of CT scanning is available called high resolution computerized tomography (HRCT). There are fairly consistent findings on HRCT that, in conjunction with a typical history, may be sufficient to make the diagnosis of DIPNECH. However, the gold standard for diagnosis of DIPNECH remains biopsy of lung tissue, which involves obtaining a piece of lung for analysis. This can be accomplished by several means. A fiber-optic bronchoscope ("bronchoscopy") is a small tube that can be led down to the small airways by going through the trachea and bronchi, thus reaching the lungs for biopsy. Video-assisted thoracoscopic surgery ("VATS") involves getting a piece of tissue through a small incision in the chest wall. Finally, lung tissue can be removed as part of a regular surgical procedure called a thoracotomy.
There are a variety of other tests which might need to be done to help with the diagnosis of DIPNECH. Chromogranin A is a substance released by carcinoid tumors and which can be measured in the blood. Its level may correlate to the total amount of carcinoid tumor present in the body. 5-HIAA is a chemical that is derived from serotonin (a hormone produced by carcinoids), and may be elevated in the urine when carcinoids are present. It is usually measured by collecting urine for 24 hours. Another blood test that might be done is a neuron specific enolase (NSE). This is a screening test for certain types of lung cancers but it is NOT elevated in DIPNECH. It would be ordered by your doctor as a screening test to make sure you don't have a lung cancer.
A PET scan is a way of finding tumors in the body, and measuring whether those tumors are actively growing. A DIPNECH carcinoid will be evident on PET scanning but there will not be any other tumors elsewhere in the body. A more specific scanning test for the presence of carcinoid tumors would be an octreotide scan. Plain X-rays of the chest will probably not show anything other than any fairly large carcinoid tumors which may be present.
Pulmonary function tests (PFTs) are a very important way of measuring how your lungs and airways are working. Since patients with DIPNECH often have significant obstruction of their small airways (bronchioles), they usually will be followed with PFTs to monitor their progress. One of the more important measures of obstruction is the FEV1, which is reported as a % of expected value for one's age.
PNCs can sometimes be found in the vicinity of certain types of lung injury, such as bronchiectasis or lung cancers. This is not
DIPNECH. In DIPNECH, the PNCs are proliferating into the bronchioles for no apparent reason. When carcinoid tumors appear, they are arising from the PNCs which are already present.
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Sadly, at this time there is no known or proven treatment for DIPNECH. However, there are some things to consider. I would strongly recommend that anyone with a chronic lung condition such as DIPNECH be vaccinated against preventable infections such as influenza, pneumonia and whooping cough. Catching one of these deadly infections could be disastrous if you already have compromised airways. The flu vaccine should be the injectable (or "killed" virus) type of vaccine, not the nose spray. Pneumonia can in some cases be prevented with a pneumococcal conjugate vaccine, and whooping cough is prevented with a vaccine called TdaP.
You should have your oxygen levels checked while awake and while asleep. Some patients with DIPNECH have low blood oxygen levels leading to symptoms like fatigue and headaches. This can easily be corrected by receiving an oxygen supplement. There is a possibility that PNCs may sense low levels of oxygen, and that this may cause them to release their chemicals that lead to more inflammation.
Steroids are medicines that, among other things, reduce inflammation. In DIPNECH it is believed that the PNCs are causing inflammation to the bronchioles. Therefore there may be some benefit to using steroid medications although they are certainly not
a cure. They can be administered either by mouth or as an inhaler. The latter can be used over long periods of time. Short courses of oral steroids might be of some benefit to help you through illnesses such as colds where there might be worsening of your symptoms from increased mucus production in your chest. There are some risks to taking steroids, like any medicine, so you should discuss this carefully with your doctor.
Bronchodilators, such as albuterol, probably would not be helpful in DIPNECH. These medicines are meant to open up the bronchioles in diseases like asthma where the airway constriction is reversible. In DIPNECH the small airways are irreversibly constricted due to the presence of the PNCs in the airways, and to scarring. However, airway dilation can be measured with PFTs, and if it can be shown that the airways are opened by a bronchodilator, such as albuterol, then they might be helpful.
There is a medicine called Sandostatin (the generic name is octreotide) that is used to prevent Carcinoid Syndrome in patients with intestinal carcinoids. In this illness, the carcinoids release hormones that cause flushing and diarrhea, as noted above. The carcinoids in DIPNECH have not been reported to cause classic Carcinoid Syndrome, but there is no doubt that they do release substances that are causing symptoms such as cough. It may be that octreotide will inhibit the PNCs enough to at least diminish coughing, and several DIPNECH patients, including my wife, have reported improvement in their coughing with octreotide. Long term studies need to be done on this.
Surgery may be one of the few treatments that offer a chance for some improvement. When a diseased portion of the lung is removed, such as when a carcinoid tumor is resected, the surrounding healthy lung expands and may improve overall pulmonary function. This has been reported in the medical literature on DIPNECH. My wife's FEV1 went from 29% of predicted to 35% of predicted after she underwent a thoracotomy for removal of a 5 cm (2 inch) carcinoid in her right upper lobe. Finally, there are a few patients with DIPNECH who progress to severe airway obstruction. In this case there needs to be consideration of lung transplantation.
Finally, I would like to point out that the carcinoids that occur in the context of DIPNECH are not typical cancers. The carcinoids should not be treated with the chemotherapy agents that are used for other types of carcinoid tumors.
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REASONS for HOPE
It is my hope that the information presented above will help you understand your condition better. As a physician, and the husband of a wonderful wife who happens to have DIPNECH, I have learned that knowledge imparts a sense of control over one's destiny and highlights the path of healing, both physically and emotionally. I believe that if more information can be shared by patients and physicians, then a better understanding of DIPNECH will be found and perhaps some more effective treatments. Along these lines I hope to have a blog site for DIPNECH up and running in the next few days. The second and third pages of this website will provide information for physicians to learn about DIPNECH, and will give patients with DIPNECH an opportunity to share their stories. I am aware of some interesting developments. National Jewish Hospital in Denver has been contacting patients with DIPNECH in order to obtain DNA samples in order to try to detect genetic markers for DIPNECH. In addition, a review of DIPNECH was published by the Mayo Clinic in Phoenix this year, and the authors are calling for a national database on DIPNECH, which is precisely the sort of effort it will take to understand this illness.
If any reader would like to contact me about any aspect of DIPNECH, you can use my email address for this site which is firstname.lastname@example.org
. I will check my email peridically and will absolutely respond to all inquiries.
Finally, as an example of what can be done, I would like to draw your attention to a website for an illness called lymphangioleiomyomatosis (LAM). This is a rare illness involving smooth muscle cells in the lungs which only affects women. It has surprising similarities to DIPNECH. Twenty years ago it was essentially unheard of by the medical community, but through the work of a few people, there is now a foundation for it that has raised $20 million dollars for research, and is now sponsoring the first clinical trials for a new drug that poses some promise for treatment. The website is www.thelamfoundation.org
and I would invite you to visit it as an example of what can be done. I would welcome anyone who wants to help with updating my DIPNECH website to write to me at my email address.
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