Thyroid-stimulating hormone (TSH) is a growth factor associated with the initiation and progression of well-differentiated thyroid cancer (WDTC). Atypia of undetermined significance and follicular lesion of undetermined significance (AUS/FLUS) are the most uncertain cytological diagnoses of thyroid nodules. The aim of the study was to determine the association of histopathological diagnosis with preoperative serum TSH levels in patients with AUS/FLUS thyroid nodule diagnosis. Among 5028 individuals with thyroid nodules, 342 (6.8%) with AUS/FLUS diagnoses were analyzed. The frequency of all histopathology diagnoses was assessed for associations with preoperative serum TSH levels. The median TSH concentration was significantly higher in patients with AUS/FLUS diagnosis and histopathology of WDTC than in patients with the same cytology result and histopathology of a benign tumor (p < 0.0001). The diagnostic potential of serum TSH level was determined to evaluate risk of malignancy in patients with thyroid nodules classified into the Bethesda III category. ROC analysis showed the TSH concentration at a cutoff point of 2.5 mIU/L to be an acceptable prognostic factor for WDTC. For this optimal cutoff point, the AUC was 0.877, the sensitivity was 0.830, and the specificity was 0.902. Preoperative serum TSH levels in patients with AUS/FLUS thyroid tumor diagnosis should be taken into consideration in the decision-making process and clinical management.

Epidemiological studies have shown a strong association between high body mass index (BMI) and papillary thyroid cancer (PTC). We assessed the clinical and histopathological features of PTC in patients with a higher BMI and compared them to analogous parameters in PTC patients with a normal BMI. We retrospectively analyzed 5021 medical records of patients admitted and surgically treated for thyroid tumors in one center between 2008 and 2018. Finally, we extracted data from 523 adult patients with PTC and stratified patients into two groups according to BMI: Group 1 with BMI < 25 kg/m² and Group 2 with BMI ≥ 25 kg/m². Data stratification was performed to estimate the association of overweight and obesity with clinical and histopathological features of PTC in both univariable and multivariable binary logistic regression analyses. Overall, compared to patients with a normal BMI, overweight and obese patients had a greater risk of minimal extrathyroidal extension (minimal ETE), multifocality and bilaterality of PTC (p < 0.001 for all). Analysis did not show that BMI was significantly associated with the more advanced tumor-node-metastasis (TNM) stage (p = 0.894). Obesity and overweight were significantly associated with higher aggressiveness of PTC. When considering various management options for PTC patients, these findings regarding overweight and obesity should be taken into consideration during the decision-making process.

Atypia and follicular lesions of undetermined significance (AUS/FLUS) is the most controversial category of The Bethesda System. The risk of malignancy (ROM) in this group is estimated as 5–15%, however, the occurrence of two or more subsequent biopsy results with AUS/FLUS diagnosis makes these clinical situations more complex. We evaluated the ROM and prognostic value of aggressive ultrasound (US) features in 342 patients with thyroid nodules (TNs) with subsequent biopsy results of AUS/FLUS. We assessed US features and compared them with the final histopathological diagnosis. Overall, 121 (35.4%) individuals after first AUS/FLUS diagnosis underwent surgery and 221 (64.6%) patients had repeated biopsies. The ROM after first, second, and third biopsies with subsequent AUS/FLUS diagnosis were 7.4%, 18.5%, and 38.4% respectively. We demonstrated significantly higher rates of occurrence of aggressive US features in patients with malignancy (p < 0.0001). The age <55 years old was also a significant risk factor for TC (p = 0.044). Significant associations were found between aggressive US features and malignancy in patients after first diagnosis of AUS/FLUS (p < 0.05). The juxtaposition of US features with the number of biopsy repetitions of TN with consecutive AUS/FLUS diagnoses may simplify the decision-making process in surgical management. Two or three consecutive biopsy results with AUS/FLUS diagnosis increases the ROM.

Background/Objectives: This study involved an analysis of clinical data, histological types, genetic predisposition, treatment and outcomes in PPB in children. Patients and methods: We conducted a retrospective review of children treated for PPB at Polish pediatric oncology centers between 2011 and 2024. Results: A total of fifteen children (seven boys, eight girls; median age of 39 months; range: 27–64 months) were included. Type II solid/cystic PPB and type III solid PPB were diagnosed in six and eight children, respectively (one not known). Overall, 93% of patients were diagnosed at up to 4 years of age. Metastatic disease at diagnosis was confirmed in three (20%) patients, localized in bones, bone marrow and lymph nodes. Diagnosis was confirmed via central pathology review in 11 patients (73%). DICER1 pathogenic variants were identified in eight patients. All children presented with respiratory symptoms. The tumor dimensions were >10 cm (n = 7), 5–10 cm (n = 5) and <5 cm (n = 2). No bilateral lung involvement was observed. Tumor biopsy was performed in six children (40%), with subsequent resection (R0) in five patients. Primary resection (R0) was achieved in three patients (20%) with type II (n = 1) or type III (n = 2). In the other six patients, non-radical resection was performed: R1 in four (27%) children (with a tumor rupture in one patient) and R2 (subtotal resection) in two children (13%). All patients received postoperative chemotherapy. Maintenance chemotherapy was given to two patients. No patient received radiotherapy as first-line treatment. Progressive disease occurred in two patients in the CNS and lungs. Relapsed disease appeared in three patients, all with CNS involvement. Conclusions: PPB is a rare, malignant tumor of early childhood with an uncertain prognosis. Despite multimodal treatment, patients remain at risk of progression or CNS relapse. Complete surgical resection remains a key prognostic factor.