Abstract | BACKGROUND: METHODS: All cases of thyroid carcinomas treated at our institution between 1980 and 2000 were reviewed and reclassified according to current histopathologic criteria. RESULTS: After review by two pathologists, 106 cases were included. Forty-three (41%) of the cases were identified as encapsulated classical PTC (E-CPTC) and 63 (59%) as encapsulated FVPTC (E-FVPTC). E-FVPTC had a higher rate of vascular invasion (16/63; 25%) than E-CPTC (2/43; 5%) (p = 0.007). In contrast, E-CPTC had a higher frequency of capsular invasion (28/43; 65%) than E-FVPTC (24/63, 38%) (p = 0.01). The lymph node metastatic rate was significantly higher in E-CPTC (11/43, 26%) compared to E-FVPTC (2/63, 3%) (p = 0.0014). All 34 noninvasive E-FVPTC lacked evidence of nodal metastases while 4 of 15 (27%) noninvasive E-CPTC presented with nodal disease (p = 0.006). Distant metastasis occurred only in four cases of E-FVPTC at presentation. These four FVPTC had extensive capsular and/or vascular invasion and no nodal disease. None of noninvasive EPTC recurred, including 30 patients treated by lobectomy without radioactive iodine (RAI) therapy (median follow-up: 8.9 years). CONCLUSION: E-CPTC resembles classical PTC in its propensity to metastasize to lymph nodes and its vascular/capsular invasive pattern while E-FVPTC behaves more like follicular carcinoma/ adenoma group of tumors. Meticulous search for capsular and vascular invasion can reliably predict the metastatic potential of E-FVPTC but not of E-CPTC. The latter can therefore be treated like unencapsulated classical PTC. Noninvasive E-FVPTC could be managed like minimally invasive follicular carcinoma by lobectomy without RAI therapy. Invasive E-FVPTC seem quite indolent if no distant metastases are found at presentation.
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Authors | Michael Rivera, R Michael Tuttle, Snehal Patel, Ashok Shaha, Jatin P Shah, Ronald A Ghossein |
Journal | Thyroid : official journal of the American Thyroid Association
(Thyroid)
Vol. 19
Issue 2
Pg. 119-27
(Feb 2009)
ISSN: 1557-9077 [Electronic] United States |
PMID | 19191744
(Publication Type: Journal Article)
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Topics |
- Adenocarcinoma, Follicular
(pathology)
- Adenocarcinoma, Papillary
(pathology)
- Adult
- Aged, 80 and over
- Carcinoma, Papillary
(pathology)
- Female
- Humans
- Lymphatic Metastasis
(pathology)
- Male
- Middle Aged
- Neoplasm Invasiveness
(pathology)
- Retrospective Studies
- Thyroid Gland
(pathology)
- Thyroid Neoplasms
(pathology, surgery)
- Treatment Outcome
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