Pleural effusion as a novel prognostic factor in metastatic thyroid carcinoma

Metastatic papillary thyroid carcinoma in pleural effusion: a case report and review of the literature

INTRODUCTION

Papillary thyroid carcinoma accounts for the most common type of thyroid cancer of well-differentiated type. Papillary thyroid carcinoma is featured by biologically low-grade and less aggressive tumors with a survival rate of 10 years in most of the diagnosed cases. Papillary thyroid carcinoma can be presented with the involvement of cervical lymph nodes in about 50% of the patients, yet distant spread is very uncommon.

CASE PRESENTATION

Herein, we discuss a Saudi male patient in his early 50s with a history of papillary thyroid carcinoma who presented to the emergency department complaining of shortness of breath and a radiological finding of hydrothorax. Cytologic examination together with immune-histochemical staining and molecular studies of pleural effusion aspiration concluded the definitive diagnosis of metastatic papillary thyroid carcinoma in the pleural space.

CONCLUSIONS

Papillary thyroid carcinoma seldom causes metastatic niches in the pleural space; this is a rare clinical presentation, nevertheless, a differential diagnosis of thyroid metastasis needs to be excluded. A definitive diagnosis of metastatic papillary thyroid carcinoma can be made using clinical presentation, cytologic examination, immunohistochemical investigation, and molecular testing. The most common mutation found in papillary thyroid carcinoma cases is the V600E mutation found in the BRAF gene, yet these patients have a relatively low probability of cancer recurrence. Patients with papillary thyroid carcinoma who have the BRAF mutation frequently experience metastases and relapses of the disease after the cancer has progressed aggressively. To help with therapy planning and the introduction of BRAF inhibitors, genetic testing for BRAF mutation may therefore prove to be a useful tool, especially in cases of aggressive subtypes of TC.

Prognostic significance of lung metastasis-related finding in lenvatinib treatment for differentiated thyroid cancer

PURPOSE

This study aimed to analyze the clinical course of patients with differentiated thyroid cancer (DTC) who were treated by lenvatinib and investigate the specific criteria for the initiation of lenvatinib in lung metastasis.

METHODS

A total of 111 patients with DTC treated by lenvatinib were included in the study. Patients were divided into two groups based on the target lesion for the initiation of lenvatinib: lung metastasis group and other metastases group.

RESULTS

In the univariate analysis, the tumor size for the lung metastasis (p = 0.002) and the factor of lung metastasis group (p < 0.001) were significantly associated with overall survival (OS). Multivariate analysis revealed that the factor of lung metastasis group [hazard ratio, 0.408; 95% confidence interval (CI), 0.206-0.810; p = 0.010] was the only independent prognostic factor of OS. Of the 53 patients in the lung metastasis group, 12 (23%) had lung metastasis-related finding such as pleural effusion (n = 12), hemoptysis (n = 2), and dyspnea (n = 1) at the initiation of lenvatinib treatment. The median OS in patients with or without lung metastasis-related findings were 41.0 [95% CI, 10.4-not available (NA)] months and 62.9 (95% CI, 53.0-NA) months, respectively (p = 0.022).

CONCLUSION

Patients with lung metastasis-related finding at the initiation of lenvatinib treatment had a poorer prognosis among the lung metastasis group. It is important to consider not only the tumor size but also the presence of lung metastasis-related findings when initiating lenvatinib treatment for DTC patients with lung metastasis.