Low Density Structure Found in CT

[DimDon]

Hi,

I have been diagnosed with Marfans and have regular tests for various complications relating to Marfans - one of which is a Chest CT and an Echo to monitor a dilated Aorta.  Within the last several months I had a chest CT that showed that the maximal point of that aorta had grown somewhat to 5.5 cm (although this is a concern, it is not my primary concern that I am posting about).  What also showed up in the CT was a "low density" structure in the pancreas but it was at the edge of the image and the radiologist suggested a full pancreatic protocal for a repeat CT. My cardiologist did not know what the significance of the low density structure in the pancreas was and therefore suggested the follow-up.

I am very conserned about this finding (or lack of conclusiveness of a finding) and I know that the only way to know with any degree of certainty what is going on is to have another CT since this was an incidental finding that was in an area of the CT that was not purposely being examined.  However, I want to know what the possibilities are for nature of this "low density structure."  Could it be artifact or shadow? What is the incidence of low density structures turning out to be artifact or non cancerous? What is the significance of the structure being "low density?"  Is this low density nature typically inline with a mass of some sort (i.e. a tumor?).  

I understand that any answer would be highly speculative but I would appreciate a great deal any information regarding the possibilities and what degree of concern I should be experiencing right now.  I am a 6'4 26 year old male in relatively good health and the notion of pancreatic cancer has never even crossed my mind and I am not sure whether what degree of cocern I should be experiencing.

Thank you in advance for any clarification.

[Kevin Pho, MD]

Hello - thanks for asking your question.

As was commented below, cancerous tumors normally show up as hyperdense or normodense as compared to the adjacent pancreatic tissue.  

Possibilities include cystic lesions.  These would include retention cysts (fluid containing spaces usually of no clinical significance), pseudocysts (which develop as a result of inflammation and necrosis), or cystic neoplasms (such as mucinous cystadenoma/cystadenocarcinoma, mucinous duct ectasia (intraductal papillary mucinous tumor), serous cystadenoma and papillary cystic neoplasm.  

Malignant potential for these lesions range from none to highly malignant.  MRI and endoscopic ultrasound are other modalities used to elucidate the cause of the lesion if the repeat CT scan is not conclusive.  

Pancreatic cancer is rare below the age of 45.  Surgeon is correct in that pancreatic cancer is normally primary.  Metastasis to the pancreas ranges from 3.5-4.7% of cases with the kidney, breast, stomach, colon, and lungs being the most common primaries.  

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Thanks,
Kevin, M.D.

[JackieG]

Obviously, further testing is called for. However, I would point out two points regarding the low density finding:

(1) Low density images on CT Scans are generally not cancer. Cancerous tumors show up as more dense.

(2) Pancreatic cancer in almost never the primary source of cancer. Pancreatic cancer is virtually always the result of metasases from some other primary cancer source or sources, and by the time it has spread to the pancreas, it has generally spread through multiple areas of the body. This is what accounts for the less than one percent 5-year survival rate for pancreatic cancer patients.

Follow up with additional tests, but I wouldn't stress out over a diagnosis of pancreatic cancer.

Good luck,
Chicken Soup

[surgeon]

The above comment is quite correct in stating that low density shadows are not likely to be cancer. It is absolutely incorrect, however, that tumors of the pancreas are not usually primary; in fact, they virtually always are. The person who wrote that post may have been thinking of liver; a very different organ.