Table of ContentsDefinition / general | Diagnosis | Prognostic factors | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Molecular / cytogenetics description
Cite this page: Jug R, Jiang X. Invasive EFVPTC. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidinvasiveEFVPTC.html. Accessed December 3rd, 2021.
Definition / general
- Prognostically distinct entity from counterpart NIFTP (non invasive follicular thyroid neoplasm with papillary-like nuclear features)
- Same nuclear features and follicular architecture as NIFTP but with vascular or tumor capsule invasion present
- Good prognosis
- Based on an international, multidisciplinary, retrospective study in which 101 participants had invasive EFVPT, 12 patients experienced an adverse event (including 5 patients developing distant metastases and 2 patients dying of the disease) by a median follow up time of 13 years (JAMA Oncol 2016;2:1023)
Microscopic (histologic) description
- Tumor invades capsule or extends into adjacent thyroid tissue, OR has evidence of lymphovascular invasion
- Nuclear features of papillary thyroid carcinoma:
- Size and shape: nuclear enlargement / overlapping / crowding, elongation
- Nuclear membrane irregularities: irregular contours, grooves, pseudoinclusions
- Chromatin characteristics: clearing with margination / glassy nuclei
- Follicular growth pattern may be microfollicular, normofollicular or macrofollicular with abundant colloid
Microscopic (histologic) images
Contributed by Andrey Bychkov, M.D., Ph.D.
Contributed by Rachel Jug, M.B.B.Ch., B.A.O.
High power (40×) H&E images demonstrating nuclear features of PTC:
- FNA samples are usually hypercellular with neoplastic cells containing nuclear features of papillary thyroid carcinoma arranged in microfollicles
- Nuclear features are more subtle than conventional papillary thyroid carcinoma
- Colloid may be present
- Cannot distinguish invasive EFVPTC from NIFTP on cytology, as cannot evaluate capsule on FNA
Molecular / cytogenetics description
- Shares molecular features (RAS type mutations) with follicular adenoma, follicular carcinoma (Mod Pathol 2010;23:1191)