SPECT/CT and I131 therapy of brain metastases from follicular variant papillary thyroid carcinoma (FVPTC)

Multiple Simultaneous Rare Distant Metastases as the Initial Presentation of Papillary Thyroid Carcinoma: A Case Report

Papillary thyroid carcinoma (PTC) commonly metastasizes to regional lymph nodes. However, they infrequently cause rare distant metastases (RDMs), with the exclusion of lungs and bone metastases. RDMs are seldom identified prior to a primary thyroid cancer diagnosis. Therefore, cases initially presenting with synchronously multiple RDMs from PTC are extremely infrequent. This is a rare case of a 48-year-old man with initial diaphragm, pancreatic, and liver tumors from PTC. Following resection of the tumors, an ultrasound-guided fine-needle aspiration (US-FNA) cytology of a mass in the thyroid's left lobe revealed PTC. After postoperative recovery for more than 4 months, physical examination identified an irregular large nodule in the thyroid's isthmus and left lobe, a swollen lymph node in the left neck, and a mass in the right parotid gland. Ultrasound reexamination revealed numerous hypoechoic masses as follows: one in the thyroid's isthmus and entire left lobe (7.3 × 5.9 × 5.1 cm) and multiple in the thyroid's right lobe (0.2-0.3 cm). Ultrasound examination also showed several swollen lymph nodes in the left neck, a mass in the left gluteus maximus, and several masses in both the bilateral parotid and salivary region. The US-FNA's pathological examination confirmed metastatic PTCs in the left gluteus maximus and bilaterally located in the parotid and salivary gland. 18-fluorodeoxyglucose positron-emission tomography and computed tomography scan revealed abnormal uptakes in numerous locations (e.g., the thyroid's isthmus and left lobe, bilateral parotid gland, subcutaneous tissues, etc.). The patient underwent palliative therapy, including total thyroidectomy, bilateral central neck dissection, left lateral neck dissection, and excision of the bilateral parotid and salivary gland. A whole-body scan post-therapeutic radioactive iodine ablation showed exclusive thyroid bed uptake. Subsequently, the patient underwent continuous thyroid stimulating hormone repression therapy and was treated with lenvatinib chemotherapy for ~8 months. The primary thyroid tumor, pancreatic metastasis, and cervical lymph node metastasis were both positive for BRAF ^V600E and TERT promoter (C288T) mutations. After 13 months of follow-up, the patient is currently in stable clinical conditions. In conclusion, the present case is an extremely rare occurrence of simultaneous multiple RDMs from PTC as the initial presentation.

Effect of Iodine Intake on p14ARF and p16INK4a Expression in Thyroid Papillary Carcinoma in Rats

BACKGROUND

Iodine intake is related to thyroid disease. This study investigated the effect of the amount of iodine intake on p14ARF and p16INK4a expression of thyroid papillary carcinoma in rats.

MATERIAL AND METHODS

A cohort of 240 SD rats were randomly divided into control group, low iodine, normal iodine, and high iodine groups (n=60 per group). We inoculated 2 × 10(5) papillary thyroid carcinoma (PTC) cells on the left side of the thyroid gland. After 6 and 12 weeks, serum thyroid hormone level and urine iodine level were measured in addition to morphological observations of tumor tissues. Expression of p14ARF, p16INK4a was detected by immunohistochemical staining.

RESULTS

The expression of p14ARF, p16INK4a, FT3, and FT4 levels in all iodine-treated animals were significantly lower than in the control group, while TSH level was significantly higher (P<0.05). Compared to the normal iodine group, the low and high groups had lower p14ARF and p16INK4a expression, lower FT3 and FT4 levels, higher TSH levels, and heavier tumors (P<0.05). In a further between-group comparison, p14ARF and p16INK4a expression and FT3 and FT4 levels at 12 weeks were lower than at 6 weeks. Expression of p14ARF and p16INK4a were positively correlated with FT3 and FT4, and negatively correlated with TSH and tumor weight.

CONCLUSIONS

Low and high iodine diet intake could reduce p14ARF and p16INK4a expressions and promote tumor development.