Monday, September 18, 2006

Follow-up to Pulmonary-thyroid

This is the patient with the hot pulmonary nodule and lung mass.
We decided to start with the thyroid and a bronch. The thyroid mass (it was not cystic on CT) was a follicular carcinoma with local invasion. No lymphnodes and the other lobe was clean.
The bronch was non-diagnostic and radiology felt the mass was too low and there was too much lung in its way for a good CT-guided needle.
She went to see our CT surgeons and we figured out why the bronch was non-diagnostic: it was not a lung mass but a diaphragmatic mass. It was an aneuploid adenomatoid tumor still not clearly characterized. Incidentally, there was a second focus of this same adenomatoid tumor in the superior segment of that LLL, which had not been seen on CT or PET (at ~7mm).
What do you think?

1 comments - CLICK HERE to read & add your own!:

nuclearvision said...

Great case. Multiple good teaching points for everyone to learn from:

1) Lesions close to the diaphragm are very prone to misregistration artifact between the transmission CT and PET. This is because the PET is acquired over several breaths and the CT is usually only takes one breath. A dedicated CT scan of the chest will frequently help clarify the location of a lower lobe lesion or lesion in/on the diaphragm or liver (coronal MPR's really help)

2) Many will reccomend a PET for lesions above 5mm. I don't. 5mm is very close to the intrinsic resolution of a PET scanner. I find I have to hedge too much when lesions are that small and usually only rec a PET for >10mm.