minimally invasive follicular thyroid carcinoma

Infiltration of the capsule, vascular invasion, and/or neoplastic extension into the adjacent parenchyma are regarded as prerequisites for the diagnosis of follicular carcinoma.

In modern practice, most of these tumors fall into the category of follicular carcinoma, minimally invasive (FCMI) characterized by evidence of limited capsular or vascular invasion with an excellent long-term prognosis and a good patient outcome.

Notwithstanding the wide acceptance of the diagnostic criteria established by the World Health Organization for the classification of follicular carcinomas in particular, they have been difficult to apply and have led to a great deal of confusion.

This confusion is compounded when applied to "low-grade" or "minimally invasive" follicular carcinoma because of the poor reproducibility of the classification and the variable results reported in the literature.

Our surgical colleagues face a similar lack of a standardized treatment for low-grade follicular carcinomas, which leads to unnecessary surgical treatment. Standardization of histologic criteria is necessary to promote confidence and uniformity in the therapeutic approach of these tumors.

Some authors believe that a FCMI is defined as an encapsulated follicular tumor (not papillary), with only small to medium vessel invasion within or immediately adjacent to the tumor capsule and/or up to full-thickness capsular transgression without accompanying extension into the thyroid parenchyma with intervening fibrosis.

See also

 thyroid follicular anomalies

• follicular thyroid carcinoma (FTC)

  thyroid gland tumors

Open references

 Prognostic impact of Ki-67 labeling index in minimally invasive follicular thyroid carcinoma.
Ito Y, Hirokawa M, Miyauchi A, Masuoka H, Yabuta T, Fukushima M, Kihara M, Higashiyama T, Kobayashi K, Miya A.
Endocr J. 2016 Oct 29;63(10):913-917.
PMID: 27432822 Free

 Risk Factors for Distant Metastasis in Patients with Minimally Invasive Follicular Thyroid Carcinoma.
Lee YM, Song DE, Kim TY, Sung TY, Yoon JH, Chung KW, Hong SJ.
PLoS One. 2016 May 12;11(5):e0155489. doi : 10.1371/journal.pone.0155489
PMID: 27171147 Free

 Minimally invasive follicular thyroid carcinomas: prognostic factors.
Stenson G, Nilsson IL, Mu N, Larsson C, Lundgren CI, Juhlin CC, Höög A, Zedenius J.
Endocrine. 2016 Aug;53(2):505-11. doi : 10.1007/s12020-016-0876-y
PMID: 26858184 Free