Endocrine Abstracts

Background: Among the lung carcinomas metastasizing to the thyroid, adenocarcinomas are the commonest followed by squamous, small cell, large cell and bronchioloalveolar carcinomas.

Case presentation: A 55-year-old man who presented with superior vena cava syndrome was found to have an 11 cm mediastinal mass encasing superior vena cava and compressing trachea and esophagus. The mass reached right pulmonary hilus. A bronchoscopic biopsy showed small cell carcinoma of the lung. The thyroid appeared normal on computed tomography (CT) of the chest. The patient was given chemotherapy with cisplatin and etoposide and external radiotherapy. Six months after the presentation, multiple brain metastases were detected on magnetic resonance imaging. Chemotherapy was changed to topotecan and cranial irradiation was performed. Ten months after the presentation a right thyroid nodule was detected on CT scan of the chest. On physical exam, a right thyroid nodule was palpable. FT₄, FT₃, TSH levels were within normal limits at that point, as well as antithyroglobulin and antithyroid peroxidase antibodies which were performed at a later date. Thyroid ultrasonography (USG) showed a 26.2×16.8×15.7 mm hypoechoic solid nodule with irregular borders in the right thyroid lobe. USG-guided fine needle aspiration showed metastasis from small cell lung carcinoma. His cranial metastases worsened. He developed right cervical lymph node, pancreatic and meningeal metastases and passed away 15 months after the initial presentation.

Discussion: We report a rare case of thyroid metastasis from small cell lung carcinoma. After reviewing the literature and this case, we conclude the following:

1) Metastasis to the thyroid gland indicate poor prognosis, especially metastasis to the thyroid from lung carcinomas represent preterminal events.

2) In any patient with a known history of malignant disease, the appearance of a new thyroid mass should trigger a thyroid fine needle aspiration biopsy to search for metastatic disease.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.