Гістопатологічний аналіз випадкових папілярних тиреоїдних карцином за хвороби Грейвса на тлі дифузного зоба та результати післяопераційного спостереження за пацієнтами

The aim is to compare the histopathological characteristics of incidental papillary thyroid carcinomas (IPTC) in Graves’disease (GD) with diffuse goiter (DG), revealed by the macroscopic description of postoperative material (macro- incidental papillary thyroid carcinomas — MIPTC) and only by microscopic examination of histological specimens (true occult papillary thyroid carcinomas — TOPTC); to find out the possible differences in the postoperative course of the disease in patients with MIPTC and TOPTC. Material and methods. A comparative histopathological analysis of 16 MIPTC and 31 TOPTC revealed in 47 patients with GD and DG, operated during the period from 2008 to 2019, was performed. The results of postoperative follow-up regarding the use of radioiodine therapy (RIT) and the presence of recurrences of IPTC were compared. Results. All examined IPTCs did not exceed 10 mm in size. The frequency of MIPTC was significantly lower than that of TOPTC (34.0% vs 66.0%, p=0.0036; odds ratio (OR)=0.26). The average tumor size, in contrast, was larger in the first than in the second group (5.8±1.2 mm vs 2.8±1.2 mm, p <0.0001). No significant differences in the dominant tumor architecture or their invasivecharacteristics were observed between two groups, in addition to more frequent signs of intrathoroidal spread of MIPTCs compared with TOPTCs (37.5 vs 6.5%, p<0.0130; OR=8.70). None of the tumors in both groups showed signs of extrathyroidal extension; all IPTCs belonged to the pT1a category in accordance with the 8th edition of the TNM classification. The duration of postoperative patients’ follow-up did not differ significantly in both groups and was 3,9±2,7 vs4,2±3,3 years, (р=0,9999). Thirteen of 47 (27.7%) patients underwent RIT course after surgery, while none of the patients had regional or distant metastases. There were also no cases of local or regional recurrence of IPTC. Conclusions. All IPTCs in GD with DG were microcarcinomas sized up to 10 mm. MIPTCs and TOPTCs were characterized by similar structural characteristics and low invasive properties. During postoperative follow-up (from 0.2 to 11.2 years), no patient had local or regional recurrences, regardless of whether patients underwent a course of RIT or not, which calls into question the feasibility of using RIT in the presence of IPTC in patients with GD on the background of DG.