TSTCs - Too Small To Characterize

TSTCs or ' Too Small To Characterize' Lesions

• Hepatic lesions 1.5 cm in diameter or smaller are frequently difficult to characterize at CT and are often reported as being “too small to characterize” (TSTC) by the interpreting radiologist.
• Most of the TSTCs are hypodense.
• In a patient without a known malignancy, TSTCs should be considered benign.
• Single TSTC in patient with malignancy are considered benign.
• If >1 TSTCs in a Oncology patient, they are mostly benign, especially if they are homogenous and sharply defined.
• Of cancers Ca. Breast TSTCs are more likely to be a metastatic lesion, than others (Ca Breast > Colorectal > Lymphoma).
• TSTCs are followed up, to look for change in size.

References
1. Hepatic lesions deemed too small to characterize at CT: prevalence and importance in women with breast cancer. Radiology 2005.
2. Liver Incidentalomas http://www.radiologyassistant.nl/en/p45a5e818c709d