Extensive vascular invasion is a marker of risk of relapse in encapsulated non‐Hürthle cell follicular carcinoma of the thyroid gland: a clinicopathological study of 18 consecutive cases from a single institution with a 11‐year median follow‐up

Abstract

EFC is a low-risk carcinoma, with no patients' deaths after a median follow-up of 11 years. Extensive vascular invasion should be considered as a risk factor for relapse. A conservative surgical approach is recommended. Since relapses may occur up to 14 years after the initial surgery, life-long follow-up is advisable.

Prognostic factors of recurrence in encapsulated Hurthle cell carcinoma of the thyroid gland

“…In the current series, vascular invasion was by far the most pow- erful predictor of recurrence (P Ͻ.0001) in patients with EHC, whereas capsular invasion was not significantly associated with tumor recurrence. This correlation between extent of vascular invasion and adverse outcome was found in a small series of encapsulated non-Hurthle cell follicular carcinomas 5 and in larger series analyzing follicular carcinomas in general without emphasis on its oncocytic variant. 4,20 It is truly remarkable that the number of foci of vascular invasion that place patients at high risk of disease recurrence (Ն 4 vessels) is very close to the number found by Lang et al 4 in 1986 (Ն 5 foci).…”

“…In 1986, Lang et al 4 studied a large number of follicular carcinomas and demonstrated that the number of foci of vascular invasion is an adverse prognostic sign even in encapsulated tumor. Recently, Collini et al 5 found identical results in encapsulated nononcocytic follicular carcinoma. However, in most publications, including the above-mentioned studies, encapsulated Hurthle cell carcinomas (EHCs) are either not included or diluted with their non-Hurthle cell counterparts and not analyzed separately.…”

“…With regard to capsular invasion, the results of the current study are in congruence with those from the majority of studies regarding the subject, which did not find a correlation between the extent of capsular invasion and outcome in patients with encapsulated follicular carcinomas (including Hurthle and non-Hurthle cell phenotypes). 5,16 Based on the above data, we believe that EHCs cannot all be assembled under the "minimally invasive" category, a term that denotes limited invasion and, more important, excellent prognosis. Indeed, some EHCs harbor extensive vascular invasion, which implies a high risk for recurrence.…”

“…4,21 Others find this designation quite arbitrary and prefer using descriptive terms such as "encapsulated follicular carcinomas with extensive vascular invasion." 5 Whatever the designation, we believe it is important to avoid the use of the term "minimally invasive" for these aggressive encapsulated follicular neoplasms. It is also crucial to explain in the pathology report the prognostic significance of an encapsulated follicular carcinoma with extensive vascular invasion.…”

Impact of historic histopathologic sample review on the risk of recurrence in patients with differentiated thyroid cancer

“…Minor vascular invasion (small number of foci confined to intracapsular vessels) appears to have a low risk of SIR (less than 5%) (28)(29)(30). On the contrary, more than 4 foci of vascular invasion are associated with a poor prognosis, mainly in follicular carcinomas (30)(31)(32). This situation seems to be uncommon in papillary carcinomas, even more in micro PTC, with a prevalence of less than 4% (25,26,28,(33)(34)(35).…”