Conventional papillary thyroid carcinoma with intraglandular lymphatic dissemination shows more aggressive features

To investigate the invasive capability and other clinicopathological features of conventional papillary thyroid carcinoma (CVPTC) with intraglandular lymphatic dissemination.

Seventy-three conventional papillary thyroid carcinoma patients receiving total thyroidectomy were analyzed in this study. The expression of BRAF-V600E, D2-40 and CD31 in all thyroid samples was detected by immunohistochemical staining. The results were evaluated by two pathologists and were statistically analyzed. The rate of positive BRAF-V600E expression and the clinical invasiveness of CVPTC with intraglandular dissemination, multifocal non-intraglandular dissemination-CVPTC and single focus-CVPTC were evaluated. The correlation between BRAF-V600E expression, lymphatic vessel density, microvessel density and the clinicopathological characteristics of conventional papillary thyroid carcinoma were assessed.

Twenty-five intraglandular dissemination-CVPTC, 17 multifocal non-intraglandular dissemination-CVPTC and 31 single focus-CVPTC cases were included in this study. The results showed that BRAF-V600E expression was independently correlated with intraglandular dissemination, age and pN staging (P < 0.05). The lymphatic vessel density in the intraglandular dissemination-CVPTC group was higher than that in the non-intraglandular dissemination-CVPTC group (P < 0.05). Compared with cases without intraglandular dissemination, intraglandular dissemination-CVPTC was associated with a younger age, higher lymph node metastasis rate, pN staging, the expression of BRAF-V600E and increased Capsule invasion and lymphovascular tumor thrombus (P < 0.05). During the follow-up of 30 months (median 15 months), two patients in the intraglandular dissemination-CVPTC group had cervical lymph node metastasis after the first operation.

Intraglandular dissemination-CVPTC shows more aggressive features, and intraglandular lymphatic dissemination may be a potential biological indicator of poor prognosis.