Endocrine Abstracts

Introduction: Intrathyroid metastases are rare (less than 1% of thyroid cancers). They can be synchronous or metachronous. The origin of primary cancer is variable; the kidney, lung, stomach and breast being the most described sites.

Through this case, we describe the diagnostic difficulties that the pathologist may encounter in the identification of these metastases.

Materials and methods: We report a case of intrathyroid metastasis of a pulmonary papillary micro carcinoma.

Results: She was a 73 year old patient with no particular pathological history, who presented a right spinal swelling appeared 2 months ago and gradually increasing in size. She had dyspnea and swallowing discomfort without signs of dysthyroidism. Physical examination found a free thyroid gland as well as lymph nodes. Cervical ultrasound showed multiple cervical jugulo-carotid and subdigastric lymphadenopathy associated with an isthmic thyroid nodule of 8 mm. The lymph node biopsy concluded that there was lymph node metastasis from papillary carcinoma. The patient had a total thyroidectomy with a right functional lymph node dissection and bilateral recurrent laryngeal nerve lymph node dissection with favorable operative suites. The diagnosis of lymph node metastasis from a pulmonary papillary micro-carcinoma was made on final histological examination. The thoracic CT made subsequently objectified multiple pulmonary nodules. Fibroscopy with biopsy confirmed the diagnosis of branchic adenocarcinoma in its micro papillary form. The patient had 3 chemotherapy courses with good progress.

Conclusion: The frequency of intrathyroid metastases is probably underestimated. The examination of the thyroid and a cytopuncture at the slightest doubt seems logical. Thyroidectomy is rarely indicated. The prognosis depends on the primitive.