Multiple studies have been done on solitary pulmonary nodules in smokers.In patients who were heavy smokers and the nodule size were less than 5 mm ,the chances of malignancy were found under 1%.If the non- calcified nodule was stable for 2 years in size and shape,it was assumed to be non-malignant.The Mayo Clinic CT screening trial, found that nodules of less than 3 mm size were likely to be malignant in only 0.2%cases,size 4-7 mm nodules the rate was 0.9% and for nodules 8 -20 mm it was 18% and over 50% chances of it becoming malignant in nodules over 20 mm in size.The doubling time of most malignant SPN(Solitary Pulmonary Nodule)is between 30-400 days,nodules displaying slower doubling time are more likely to be benign. Criteria defining a nodule as highly suspicious of malignancy would include-1. Persistent non-solid (focal) ground glass nodule measuring 10 mm or more in diameter 2. Persistent mixed (or part solid) nodules 3.Solid nodule measuring 20 mm or more in diameter 4.Solid nodule with spiculated contours 5.Solid nodule containing air bronchogram or pseudocavitation 6. Solid nodule containing eccentric or dispersed calcification. The chances of the nodule being benign appear to be much more than earlier,It would appear that in another 3-4 months(when the 400 days are up),and definitely after 2 years, it is likely that the lesion would be benign if no changes are seen.
I'll get back to you soon
Hi Dr. Vakul Aren,
Thank you for your informative answer to my question. It was excellent. I might have one follow-up question and that is why I haven't rated you yet.
My doctor gave me the result of my recent CT in a short email. (Still 4mm - no change). I emailed him back to get a paper copy of the report for my records...because I know doctors look at various things on a CT (not just the size of a nodule). If I have any concerns after seeing the paper report, I might have a question. If not, I will rate your answer as excellent.
I will be available here to answer any follow up questions.Please rate my answer positively to release my dues.Thank you.
Hi Dr. Aren,
Received the official report from the CT (had much more information than my doctor's first brief email to me).
Here is the official reading. (My questions are at the bottom)
The apical "fibrotic change/ground glass" findings in the upper lungs have not changed in the last 10-11 months. The more they stay the same, the more scarring from old infection is likely. If they change, we will begin to think about an active infection. If you have not had a PPD, tuberculosis skin test in the last year or two, you should, as tuberculosis can lie dormant in the upper lobes of the lungs for years. The test is ordered, and is available and at the Birch building injection clinic. Monday, Tuesday, Wednesday, Friday I think, 9-5. No tests on Thursday. You may want to call ahead for better timing. Sincerely, XXXXX XXXXX MD CHEST CT NONCONTRAST ** HISTORY **:Followup left lung nodule Comparison: 4/3/2012, 1/24/2012, 12/1/2011 ** FINDINGS **:TECHNIQUE:Contiguous collimated transaxial slices were obtained in helicalmode from lung apices to level of adrenal glands with no IVcontrast. FINDINGS: Previously described 4 mm nodule in the lingula is unchanged. Nonew pulmonary nodules identified. Allowing for differences intechnique, previously described nonspecific biapical pleuralparenchymal fibrotic change/groundglass opacities are notsignificantly changed compared to prior chest CTs dating to1/24/2012, possibly representing inflammatory or infectiousprocess. There is no new focal consolidation. There is no pleuraleffusion. Allowing for noncontrast technique, heart and great vessels appeargrossly unremarkable, unchanged from prior studies. There is nopathologically enlarged mediastinal lymphadenopathy. Limitedviews of the upper abdomen are grossly unremarkable, allowing forlimitations of noncontrast technique. No suspicious lytic or blastic osseous lesions identified. ** IMPRESSION **:Unchanged appearance of 4 mm nodule in the lingula. According toFleischner Society guidelines, in a smoker high risk patient,continued followup in 6-12 months would be recommended. Allowing for differences in technique, previously describednonspecific biapical pleural parenchymal fibroticchange/groundglass opacities are not significantly changedcompared to prior chest CTs dating to 1/24/2012, possiblyrepresenting inflammatory or infectious process. Attention tothis area on followup is recommended. KENNY C LAI M.D.
My questions: I understand the part about "things look unchanged"....but I guess I could use a clarification on the possible infection issue.
1) If old infection, does that mean it doesn't have to be treated?
2) If new infection, are they only referring to TB? ...or possible some other kind of infection?
3) Your overall opinion, do you agree that the 6 - 12 month follow-up is appropriate? (when they say Follow-up, I assume they mean another CT?)
Thank you very much in advance Dr. Aren. (Will rate upon receiving your response).
Chronic infections like Tuberculosis are known to cause such nodules.You must have been tested extensively for any such infections(Tuberculosis,fungal infections like Histoplasmosis,Coccydiomycosis,parasitic infections,immune granulomas) when the nodule was first found.Since the nodule was not related to any such infection when found initially,it is unlikely that treatment will be required for any infectious cause.A new infection would cause other findings and can be safely ruled out.Yes,another CT scan for follow up after a few months would help confirm the benign nature of the nodule .