FDG PET/CT in the detection of metastases in a patient with Tg and 131I WBS negative follicular thyroid cancer

Pathological clavicular fracture as first presentation of renal cell carcinoma: a case report and literature review

Renal cell carcinoma (RCC) accounts for approximately 3% of all cancer cases. RCCs usually metastasize to the lungs, bones, liver, or brain. Only <1% of patients with bone metastases manifested clavicular RCC metastases. Thus, clavicular metastasis as the initial presentation of RCC is extremely rare. We report a patient with RCC metastasis to the left clavicle, which was first presented with pain caused by a pathological fracture. Magnetic resonance image revealed a renal tumor, and technetium-99m–methylene diphosphonate bone scintigraphy showed multiple osseous metastases. The patient eventually underwent surgery to remove the lateral end of the left clavicle and right kidney. Histopathology revealed renal tumor and clear cell carcinoma in the clavicle. Finally, we review 17 cases of clavicular metastases originating from different malignancies.

Primary squamous cell carcinoma of the thyroid on FDG PET/CT

Primary squamous cell carcinoma of the thyroid is rare. We present FDG PET/CT findings on 2 male patients with primary squamous cell carcinoma of the thyroid. Elevated FDG activity was visualized on primary thyroid tumor and metastatic lesions on both patients.

Low but measurable stimulated serum thyroglobulin levels <2 µg/L frequently predict incomplete response in differentiated thyroid cancer patients

INTRODUCTION

The study was aimed to determine the response and predictive risk factors of differentiated thyroid cancer (DTC) with measurable (0.4-2.0 µg/L) stimulated serum thyroglobulin (sTg) during the 10-24 months after radioiodine remnant ablation (RRA) and their long-term outcomes.

METHODS

Out of 839 retrospectively reviewed patients, 95 eligible DTC patients were included. Patients were classified as having incomplete response or no evidence of disease (NED). The sTg cut-off values with highest predicted accuracy for incomplete response at 10-24 months were calculated with receiver operator characteristics curve analysis.

RESULTS AND CONCLUSION

At 10-24 months after RRA, incomplete response was identified in 54 patients (57%) and 38/54 (70.4%) patients were found with structural evidence of disease. The remaining 16 patients (29.6%) had biochemical evidence of disease without structural evidence of disease. Forty-one patients (43%) were classified as having NED at 10-24 months after RRA and 27 patients (66%) did not receive further radioactive iodine (RAI) therapy and remained disease free at median follow-up of 6.5 years. Fourteen patients received second RAI treatment after 6 months and before the 10-24 months assessment time point. Of these, 2 had persistent tumor 6 years later. The sTg >0.6 µg/L at 6-10 months after RRA had optimal sensitivity (83.3%), specificity (56%) and negative predictive value (72%) of detecting incomplete response at 10-24 months after RRA. A total of 23/43 patients in the American Thyroid Association low-risk category had incomplete response after first RRA and 5/23 (21.7%) had recurrent/persistent disease at long-term follow-up.