Open AccessFalse positive localisation of C-11 methionine in a colloid nodule
Author(s) -
Sonia Mahajan,
Madhavi Tripathi,
Abhinav Jaimini,
Anant Dinesh
Publication year - 2011
Publication title -
indian journal of nuclear medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.261
H-Index - 13
eISSN - 0972-3919
pISSN - 0974-0244
DOI - 10.4103/0972-3919.106719
Subject(s) - medicine , nodule (geology) , thyroid , radiology , malignancy , positron emission tomography , thyroid carcinoma , fine needle aspiration , carcinoma , pathology , nuclear medicine , biopsy , paleontology , biology
A 45-year-old female diagnosed with carcinoma of the left breast on histopathological examination underwent both (18)F-flourodeoxyglucose (FDG) and 11C-methionine (MET) positron emission tomography/computed tomography (PET/CT) as part of a protocol comparing the utility of these tracers for predicting a response to neoadjuvant chemotherapy in breast carcinoma. Abnormal FDG and MET accumulation was noted in the left breast primary, left axillary lymph nodes, and also in a well-defined nodule present in the left lobe of the thyroid gland. Keeping in mind the possibility of thyroid neoplasm/metastasis, the patient was referred for fine needle aspiration cytology (FNAC) from the thyroid nodule that revealed features of a simple colloid nodule. Focal thyroid lesions incidentally found on (18)F-FDG PET/CT have a high risk of thyroid malignancy. Non-specific accumulation of FDG in thyroid adenomas is also known. This case highlights a potential cause for false positive on C-11 MET PET/CT in colloid adenomas, which should be kept in mind while using this tracer for oncological indications.