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Date of last update: 10/21/2017.

Forum Name: Breast Cancer

Question: Enlarged Internal Mammary Node at intercostal space

 WorryHusband - Thu Jul 22, 2010 10:46 pm

HI my wife is a breast cancer survisor who completed her treatment 5 years ago. IN recent detail CT scan, found an enlarged internal Mamamary Node at the first intercostal space measuring 1.5 cm x 1.2 cm x 0.6 cm but her blood test result showing CEA = 0.2 and CA 15.3 = 4.2 both are in very good control range. What could be the problem on this enlarged IMN ? I am very worry and please advice. Doctor who had seen my wife for the past 5 years said he is 90% sure that this is nothing bad, but if to get 100% sure, we will have to do PET scan. Please advice.

Sincerely yours,
Very worry husband
 Dr.M.Aroon kamath - Fri Jul 23, 2010 11:11 am

User avatar Hi,
I very well understand your concern.Before tests are done, it is difficult to ascribe a cause for these lymph nodes. As your wife had been treated for breast cancer earlier, it will always be assumed to be a secondary deposit, unless proved otherwise.

You have not indicated what kind of a management she had received(breast conservation vs modified radical mastectomy/radiotherapy/ +/- adjuvant therapy)

The normal internal mammary lymph nodes are not routinely demonstrable on CT imaging, and it has been assumed that a lymph node with a diameter > 6 mm visualized on a CT scan probably represents malignant lymphadenopathy in patients with known recurrent breast cancer.

Now the crucial step will be to find out if that node contains malignant deposits. A PET scan is very good at identifying malignant tumors.

Unlike CT scans(anatomically based imaging), PET scans yield metabolic-based images.It is based on identifying the high metabolic activity in tumors.

The average sensitivity and specificity across all oncological applications for FDG PET are estimated at 84% and 88%, respectively. When combined with CT (PET-CT), one can get better anatomical infomation.
False-negative results can occur in lesions < 1 cm because a critical mass of metabolically active malignant cells is needed for PET diagnosis. False negatives can also occur in tumors with inherently low metabolic rates, such as bronchioloalveolar cell carcinomas and carcinoid tumors.
False-positive FDG uptake is seen in some inflammatory conditions such as pyogenic abscesses, bacterial pneumonias, aspergillosis, and granulomatous diseases such as sarcoidosis, tuberculosis, Wegener’s granulomatosis etc.

The main disadvantage of PET is that it does not offer an histological evidence of malignancy.

One other investigatory option is an "image guided fine needle aspiration biopsy". this is technically feasible for the internal mammary nodes.The complication rates are extremely low. pneumothorax is considered to be a theoretical but extremely remote risk in experienced hands.One other concern is seeding of tumour cells along the needle-track, but this is also considered quite rare. The distinct advantage is an histological proof of malignancy. False negatives are of course a concern.

In the case of your wife, it is indeed essential to know the nature of this lymph node because 5 years have elapsed since the original tumor and there are no other indicators of recurrent disease.

In such cases,the decision regarding further management has to be based on the results from a PET scan. Whether an histological proof is necessary or otherwise before planning further therapy in a given case will be best left to the oncologist to decide.If deemed necessary, then an image guided fine needle aspiration biopsy will be an option.
Good luck!
 WorryHusband - Fri Jul 23, 2010 8:41 pm

Hi Doc,

Thanks for your reply and advice. My wife had a radical mastectomy in March 2005 and completed the 6 courses of chemo in Sept 2005. She had been under close monitoring all these while and her tumor marker reading is always good. She is not on any medication as the doc ( Onco ) not recommending any as he think is not required.

I am not sure how my wife and myself would storm thru this round of suspicious image again but we will be seeing the onco doc on next Tuesday for his advice. Hope everything is well, as we do not see any other symptoms and the tumor marker especially CA15.3 is maintainig well without any elevation.

Thank you for your recommmendation.
 Dr.M.Aroon kamath - Mon Jul 26, 2010 11:14 am

User avatar Hi,
Thank you for the update. i sincerely hope that having done so well all these years, your wife continue to do so. Good luck!

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