Endocrine Abstracts

Introduction: It is well known that struma ovarii, choriocarcinoma and follicular thyroid carcinoma can cause thyrotoxicosis. We report a rare case of a man with carcinomatosis presenting with acute thyrotoxicosis, unilateral proptosis and neck swelling.

Case report: A 48-year-old man presented with a 2 weeks history of neck swelling, profuse sweating, heat intolerance, agitation, weight loss and mild unilateral proptosis. He was a smoker with a 20 years pack history. On examination he was thyrotoxic. Thyroid function tests showed thyrotoxicosis; free T4 42 pmol/l, TSH <0.05 μ/l. Carbimazole 40 mg was commenced. One week later he presented again with progressive dysphagia and dysphonia.

Examination revealed severe worsening of his right eye proptosis, sinus tachycardia, a firm, smooth, goitre and evidence of retrosternal extension. There was right eye proptosis, diplopia and an inferior hemifield defect. Thyroid peroxidase antibodies were negative.

CT orbits showed a large soft tissue mass 2.5×1.8×2.3 cm superomedial to the right orbit with mass effect, deviation of the optic nerve and medial oblique. CT neck and chest showed a large homogeneous goitre with retropharyngeal space soft tissue thickening with multiple low attenuation lesions in the lung parenchyma, liver, kidneys, peritoneum and body of pancreas. There were multiple enlarged lymph nodes.

Right orbital decompression biopsy and thyroid biopsy revealed high grade poorly differentiated malignancy of uncertain origin at both sites. Immunohistochemistry excluded lymphoma and sarcoma. He required an emergency tracheostomy following surgery. He received one course of chemotherapy for presumed small cell lung cancer and died nine days after the second presentation.

Conclusion: In patients presenting with neck swelling and proptosis it is important to consider rare causes. This is an unusual presentation of carcinomatosis presenting as acute thyrotoxicosis and thyroid eye disease.