Endocrine Abstracts

A 42-years woman presented with hypothyroidism, a large, firm, irregular goiter, severe cervical and preauricular pain, 2 weeks after an episode of respiratory infection. Laboratory findings certified subacute thyroiditis and autoimmune hypothyrodism: TSH>50 μUI/ml, FT₄=6.5 pmol/l, ATPO>1000 U/ml, ATGL>1000 U/ml, ESR=115 mm/1 h. Thyroid ultrasound showed hypoechogenic pattern with a nodule on the right lobe and low Doppler signal. Fine needle aspiration biopsy showed features of chronic thyroiditis and fibrosis. Prednisone 30 mg/day and levothyroxine replacement treatment were started temporary relief of symptoms and improvement of biological profile. However, she relapsed after 3 months when the steroid was tapered, while the goiter size increased and it became hardener. Four months after the first admission, she was submitted to surgery, and total thyroidectomy was performed with difficult dissection due to severe fibrosis and local invasion towards the left recurrent nerve, hyoid muscles, trachea and esophagus. The pathology report confirmed thyroid fibrosis with Riedel features.

Postsurgery ATPO level decreased but she presented dysphonia and documented hypoparathyroidism. ENT evaluation certified left recurrent nerve palsy. She was placed on calcium (1000 mg) and vitamin D₃ (0.5 μg/day). Despite surgery, she continued to present cervical constriction, oedema and pain in the anterior cervical area, therefore she required methylprednisolone pulse therapy, then switched to oral treatment. Computed tomography certified residual left cervical fibrosis of 3 cm diameter and 10 cm length, from pharyngolarinx up to the supraclavicular fossa, in addition to posterior left juxtapleural pulmonary fibrosis. Euthyroidism was maintained with L-thyroxine 100 μg/day. Addition of tamoxifen at 20 mg/day improved the clinical and biological status with decrease of ESR, allowing progressive reduction of steroid treatment, with clinical relief of symptoms.

In conclusion, tamoxifen treatment added to corticosteroids, is a useful association in Riedel’s thyroiditis.