indeterminate thyroid nodule
Thyroid nodule with cytological features that cannot be definitively classified as benign or malignant on fine needle aspiration.
Full Definition
Indeterminate thyroid nodules represent a diagnostic challenge where fine needle aspiration cytology yields results that fall between clearly benign and overtly malignant categories. These typically correspond to Bethesda categories III (atypia of undetermined significance) and IV (follicular neoplasm or suspicious for follicular neoplasm). Management often requires molecular testing, repeat sampling, or diagnostic surgery to establish definitive diagnosis. The term encompasses various cytological patterns including microfollicular proliferations, nuclear atypia without definitive features of papillary carcinoma, and Hürthle cell proliferations.
Usage
Usage note: Specify Bethesda category when possible for clarity.
In Context
- "The indeterminate thyroid nodule prompted molecular testing to guide management decisions." — Clinical decision-making
- "Repeat FNA of the indeterminate thyroid nodule again yielded atypia of undetermined significance." — Cytology report