Endocrine Abstracts

Introduction: Hyperthyroidism and thyrotoxicosis can have multiple etiologies, varying from the most frequent described in clinical practice (Graves disease, toxic nodular goiter, thyroiditis) to very rare causes such as anaplastic thyroid cancer, thyroid lymphoma, amyloidosis or even secondary malignancy of the thyroid gland.

Case report: A 53 year old man presented to our department for progressive goiter enlargement in the last two months which was accompanied by dysphagia and dysphonia. The patient had a history of smoking for almost 40 years and also mentioned that in the last two weeks he lost in weight approximately 3 kg. The clinical exam was in normal limits, with the exception of multiple laterocervical adenopathies and the enlarged, firm thyroid gland which was painful and presented local inflammatory signs. The paraclinical investigations showed an acute inflammatory syndrome (ESR 42 mm/h, CRP 85.2 mg/l, Fibrinogen 606 mg/dl) with thyrotoxicosis (TSH - 0.01 mIU/ml, freeT4 - 4.13 ng/dl and total T3 - 278 ng/dl) and negative autoimmunity. The thyroid ultrasound showed a pseudonodular heterogenous aspect with decreased blood flow and multiple non-inflammatory laterocervical adenopathies, largest one being almost 2 cm. In addition, thyroid scintigraphy showed no hyperfunctioning areas while the computed tomography of the neck and thorax discovered a right apical pulmonary nodule of 35/36/46 mm. During his hospital stay he received anti-inflammatory treatment with dexamethasone and ibuprofen. His largest right laterocervical adenopathy was surgically removed and sent to the anatomical pathology department who described a ganglionar metastasis of pulmonary carcinoma with clear large cells. The patient underwent total thyroidectomy and the result confirmed a thyroid metastasis of pulmonary carcinoma. He received replacement therapy with levothyroxine and oncologic treatment with pembrolizumab, pemetrexed and carboplatin. During his last examination, after eight months of treatment, the patient was stable, presenting euthyroidism while the right apical pulmonary nodule had a dimensional regression. Unfortunately, he presented multiple cervical adenopathies for which he will undergo palliative radiotherapy.

Conclusions: This was a rare case of thyrotoxicosis which required a proffesional multidisciplinary team in order to offer an appropriate diagnosis and treatment. Secondary malignancy of the thyroid gland is quite rare, and especially in the form of thyrotoxicosis which probably was caused by a destructive invasion of thyroid tissue with malignant cells, similar to a “thyroiditis”.

Key words: thyrotoxicosis, secondary malignancy, pulmonary carcinoma