3mm & 13mm nodules in right lung

i recently went for a breast biopsy. the pre-op xray revealed a nodule and after surgery, went for a CT scan.  the scan revealed a tiny noncalcified nodule in the anterior segment of the right upper lobe measureing 3mm.  there is a second nodule in the right middle lobe anteriorly which corresponds to the abnormality on chest xray measuring approximately 13mm.  this is slightly irregularly marginated but not spiculated.  my doctor referred me to a pulmonary specialist who has ordered a PET scan based on the radiology findings (i havent met the other doctor yet).  

could you explain to me what these nodules are and based on the size and characteristics  if they are likely cancer? i am a 38 yr old female, non smoker.i smoked in college, but never heavily.  i dont and have never worked around birds.  there is no known history of cancer in my family.

btw, the breast biopsy was benign, fibroidadenoma.

[Kamal S Saini, MD, MRCP (UK), DM]

Hi,
Lung nodules may be caused by a wide variety of causes. Broadly, these can be classified as infective, inflammatory, and malignant.
It is difficult to estimate what is the cause of your lung nodules based only on your hstory and CT scan report.
PET may shed some more light on the possible causes, but may not be able to clinch the diagnosis. Further tests may be planned based on the PET report.
Do let me know the PET results.
All the best, and God Bless!

[tdbx]

are the size (13mm) and shape (irregular but not spiculated) charactersitics indicative of a benign or malignant tumor? from what i have read, the 13mm nodule, irregular shape, indicates moderate risks of malignancy.  

thank you,
tdbx

[Kamal S Saini, MD, MRCP (UK), DM]

Hi,
I think it would be better to wait for the PET report. This will narrow down the possible differential diagnoses.
It is not necessary that every irregularly shaped nodule is cancerous.
Best of Luck!

[kwazynana]

A related discussion, 13mm nodule was started.