Significance of an Insular Component in Follicular Thyroid Carcinoma with Distant Metastasis at Initial Presentation

Abstract

Risk factors for distant metastasis were studied in 82 patients with follicular thyroid carcinoma (FTC). Metastases to either the lung or bone existing at the time of presentation were confirmed by I-131 radio-iodine uptake in 10 patients. FTC with an insular component was found in eight patients. Univariate analysis of 14 possible risk factors showed 7 to be statistically significant: insular component, poorly differentiated carcinoma, trabecular component, serum thyroglobulin level before surgery, patient age at the time of presentation, solid component, and vascular invasion (ranked by p values). After further analysis of the interrelation of the factors and of the logistic regression curves, we concluded that presence of an insular component and patient age were the only independent risk factors. Distant metastasis was not detected in any of the 27 patients < or = 49 yr old. Among the 55 older patients (> or = 50 yr old), 5 of the 49 (10%) without an insular component and 5 of the 6 (83%) with an insular component had distant metastasis. The remaining older patient with an insular component but without distant metastasis showed a gradual increase in thyroglobulin levels after total thyroidectomy.

Heterogeneity of Thyroid Cancer

“…A prominent spindle-cell component, or rhabdoid, oncocytic, or clear-cell phenotype, or signet-ring cells have been observed in rare FTC cases [75, 76]. Yamashita et al [77] suggested that the insular component in FTC was an independent risk factor for distant metastases to the lungs or bones. Heterogeneity of the tumour border is an unusual finding during FTC follow-up.…”

Micro-RNAs in thyroid neoplasms: molecular, diagnostic and therapeutic implications

“…Clinicopathological and morphological criteria like age, tumour size and presence of poorly differentiated areas in a well-differentiated thyroid carcinoma have been predominantly used to predict metastasis and overall survival 35 37. However, a considerable degree of interobserver variability exists for thyroid carcinomas, especially for thyroid neoplasms with follicular morphology.…”

Follicular carcinoma of the thyroid with aggressive metastatic behavior in a pregnant woman: Report of a case and review of the literature

“…32 The lack of E-cadherin expression is proposed as an independent prognostic factor for invasion by multivariate analysis. 33,34 Our case showed less than 80% of cells expressing membrane positivity for E-cadherin.…”