Intrathyroideal papillary thyroid carcinoma presenting with a solitary brain metastasis

Cerebral metastases from thyroid carcinoma: complete remission following radioiodine treatment

BACKGROUND

Brain metastases arise in roughly 0.9% of all cases of differentiated thyroid cancer. The median survival of adult patients with thyroid carcinoma that has metastasized to the brain is less than one year. Radioactive iodine treatment is only rarely given because its efficacy is not documented. In children, the situation may be different.

METHOD

In 2005, a 15-year-old girl underwent thyroidectomy, and an oxyphilic variant of papillary thyroid carcinoma was found in ectopic thyroid tissue. The patient underwent oral, high-dose radioactive iodine treatment. The post-therapeutic I-131 whole-body scan revealed multiple metastases in the skeleton, lungs, and the soft tissues, along with physiological uptake of the residual thyroid tissue. Magnetic resonance imaging of the head revealed two brain metastases.

RESULTS

When the initial treatment was completed, additional age-adapted high-dose radioactive iodine treatment was given, up to a total activity level of 35 GBq. There followed a complete remission of all metastases in the brain, bones, lungs, and soft tissues. Computed tomography of the chest revealed stable residuals. Over the ensuing 7.5 years of follow-up, the thyroglobulin values steadily declined to less than 2 ng/mL. The patient was asymptomatic at her last follow-up in May 2013. She did not develop any delayed reaction to high-dose radioactive iodine treatment (in particular, she did not develop leukemia or any other secondary malignancy). She remained fertile: after completion of the treatment, she had two healthy children.

CONCLUSION

In this patient with multifocal thyroid carcinoma, a rare entity, radioactive iodine treatment was successful as the single treatment. This case illustrates the point that a given therapeutic modality might succeed in an individual case despite a total or near-total lack of efficacy for most patients in the same situation.

Multiple cystic brain metastases from papillary thyroid carcinoma mimicking neurocysticercosis

The papillary carcinoma of the thyroid gland is the most common type of tumor of the thyroid gland with good prognosis and low incidence of distant metastasis. The brain metastases of thyroid gland carcinoma are extremely rare. We report a patient with multiple cystic brain lesions and satisfying criteria for diagnosis of neurocysticercosis. Brain biopsy revealed brain metastases from papillary thyroid carcinoma. The tumor originated from mediastinal thyroid tissue. Even in cases when neuroimaging suggests neurocysticercosis with great accuracy, it is important to exclude metastasis. Extensive brain metastases of primary papillary thyroid carcinoma are extremely rare.

Choroid Plexus Metastasis From Papillary Thyroid Carcinoma Presenting With Intraventricular Hemorrhage

OBJECTIVE

Metastases to the choroid plexus from extracranial tumors are rare. Kidney, lung, and colon are the common primary origins of choroid plexus metastases. Choroid plexus metastases from thyroid carcinoma are very rare, with only 2 cases reported thus far. We report the third case of choroid plexus metastasis from thyroid carcinoma.

CLINICAL PRESENTATION

A 75-year-old man presented with severe headache, nausea, and vomiting. He had a history of thyroid carcinoma, which had metastasized to the lymph nodes and lung. Computed tomography, magnetic resonance imaging, and magnetic resonance angiography revealed right intraventricular hemorrhage with mild hydrocephalus, without evidence of a bleeding source. The bleeding source was assumed to be the choroid plexus metastasis in the trigone of the right lateral ventricle (following second admission).

INTERVENTION

Surgery was performed using a navigation-assisted system. The tumor was entirely removed, including some choroid plexus tissue. A ventriculoperitoneal shunt was also performed to treat the hydrocephalus. Histopathological examination revealed brain metastasis from papillary thyroid carcinoma. Postoperatively, the patient showed good recovery, with nausea and vomiting improved, and gait disturbance diminished. The patient was discharged from the hospital one month later.

CONCLUSION

Choroid plexus metastasis from papillary thyroid carcinoma is very rare, and this is the first case of intraventricular hemorrhage reported.