Papillary thyroid carcinoma coexisting with benign thyroid and parathyroid pathology: clinical and pathomorphological features

Abstract

Background. Papillary thyroid carcinoma (PTC) is the most frequent malignant neoplasm originating from follicular cells of thyroid gland. PTC is often coexisting with other benign thyroid pathology such as chronic lymphocytic thyroiditis, follicular thyroid adenoma, toxic thyroid adenoma, Graves’ disease, non-toxic multinodular goiter. PTC can be diagnosed in patients undergoing surgical treatment for hyperparathyroidism. However, the clinical and pathomorphological features of PTC in the presence of other benign thyroid or parathyroid pathology, as well as possible differences in surgical tactics, remain relevant as evidenced by previously published reports. The purpose of the study is to assess the prevalence and determine the differences in the clinical and pathomorphological parameters of PTC in the presence of benign thyroid and parathyroid pathology. Materials and methods. There were identified 91 patients with PTC, who underwent surgical treatment at the clinical bases of the Department of Surgery of the NSC “Institute of Biology and Medicine” of Taras Shevchenko National University of Kyiv. Results. In the studied PTC cohort, 31 (35 %) patients were without coexisted benign thyroid pathology and 60 (35 %) patients had it (PTC/coexisted). A statistically significantly higher number of mitoses per 10 high power fields in the PTC group were identified in 3 (10 %) patients, as compared to the absence of this pathohistological parameter in the PTC/coexisted (p = 0.037). Further analysis of these 3 cases showed that 4 mitotic figures were found in one PTC, and one mitotic figure in the other two cases per 10 high power fields (400×). Conclusions. Papillary thyroid carcinoma in patients with other benign thyroid pathology is associated with lower biological aggressiveness than PTC without comorbidity as evidenced by a lower frequency of mitotic figures per 10 high power fields. The presence of concomitant benign thyroid pathology can be considered as a favorable prognostic factor for patients with PTC.