Advanced
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In the Industry Vocabulary Test
capsular invasion
Tumor penetration through the fibrous capsule surrounding thyroid nodules.
Full Definition
A histopathologic finding indicating that malignant cells have breached the fibrous capsule that normally surrounds benign thyroid nodules or encapsulated tumors. This finding is crucial in differentiating between follicular adenoma and follicular carcinoma, as capsular invasion is one of the defining features of malignancy in follicular thyroid neoplasms. The extent and pattern of capsular invasion also influence staging and prognosis, with minimal invasion having a better outcome than extensive capsular penetration.
Usage
Usage note: Often qualified with descriptors like 'minimal,' 'focal,' or 'extensive.'
In Context
- "Histopathology revealed focal capsular invasion consistent with follicular thyroid carcinoma." — pathology report
- "The absence of capsular invasion supported the diagnosis of follicular adenoma rather than carcinoma." — pathology consultation
Also known as
capsular penetration
capsular breach
Contrasted with
capsular integrity
encapsulated tumor
Don't confuse with
vascular invasion
lymphatic invasion