Intracranial metastasis from medullary carcinoma of the thyroid 25 years after primary surgery

Abstract

Medullary carcinoma of the thyroid is an uncommon tumour. In most patients, it is confined to the neck with or without involvement of the local cervical nodes. It rarely metastasizes to the mediastinum, lungs or liver. Intracranial metastasis is extremely rare with very few reported cases in the literature. We report an unusual case of an intracranial metastasis from a medullary carcinoma of the thyroid that occurred 25 years after primary surgery. We discuss the unusual features of our case together with a review of the literature.

Brain metastasis from medullary thyroid carcinoma

“…Another patient was a 55-year-old female who was followed for 19 years without symptoms and had recurrence in the neck and around the trachea, followed by brain metastasis 10. A 57-year-old male who developed intracranial metastasis after 25 years of uneventful follow-up with no indication of systemic spread 7. The tumour was extradural, arising from the petrous apex and invading the cavernous sinus.…”

“…Papillary and follicular carcinomas characteristically have a slow growth rate with only very rare fatal outcome due to the availability of targeted therapy with radioactive iodine 6. MTC is typically a more aggressive form of thyroid cancer with higher rate of recurrence and increased mortality 4 7. The typical sites of metastasis of medullary thyroid cancer are the regional lymph nodes, which are frequently involved at the time of diagnosis.…”

“…Even though thyroid cancer, in general, is a common malignancy, only 1% of all thyroid carcinomas metastasise to brain 6–8. Of patients with thyroid carcinoma, those with metastatic spread to brain are typically older, have larger primary tumours and show evidence of extrathyroidal extension as well as distant metastasis at initial cancer diagnosis 6 9.…”

“…2 6–10 12 13 The first reported case was that of a 67-year-old female patient who had multiple cerebellar metastases from MTC 3 years after the initial diagnosis. She had extensive lymph node involvement at the time of diagnosis but no evidence of other distant metastasis.…”

“…When distant metastasis occurs, the most frequently involved organs are liver, lung, bone and mediastinum 2 3. Brain metastasis occurs in approximately 1% of all cases of thyroid carcinoma 6 7. Most of these are follicular carcinomas.…”