Choroid Plexus Metastasis of Follicular Thyroid Carcinoma Diagnosed due to Intraventricular Hemorrhage

Metastasis of the choroid plexuses: A systematic review of the literature and case illustration

BACKGROUND

Choroid plexus (CP) metastases are an extremely rare condition accounting for less than 1% of brain metastases. Due to its scarcity, little is known about this pathology and its management. Herein, we propose a review of the current literature to help its diagnosis and management.

METHODS

Through a literature review based on PubMed/MEDLINE database, we reviewed 94 cases of intraventricular metastasis of solid cancer in 28 full-text articles in English from 1980 to 2010. We have reported epidemiological, clinical, radiological, histological data, as well as management strategies and outcomes. A case report of fourth ventricular pulmonary metastasis illustrates this review.

RESULTS

Intraventricular metastases are most often reported in patients in their 6th decade. The clinical presentation is marked by acute hydrocephalus, more rarely lesional bleeding. Three-quarters of intraventricular metastases develop in lateral ventricle, then respectively in the fourth and third ventricles. Kidney cancer accounts for 45% of the cases. The treatment modalities are surgical removal in case of a single lesion and adjuvant radiotherapy and chemotherapy depending on the primary cancer. The prognosis remains poor due to dissemination via the cerebrospinal fluid.

CONCLUSION

Multiple choroid plexus metastasis is a rare diagnosis, affecting patients with a specific clinical presentation and a misleading radiological appearance. There is no standard of care for the management of these lesions and surgical approach can be challenging.

Multifocal metastases to choroid plexus from papillary thyroid carcinoma: illustrative case

BACKGROUND

Choroid plexus metastases are extremely rare from all types of malignancy, with only 42 cases reported in the literature thus far. Most of these originate from renal cell carcinoma and present as a solitary choroid plexus lesion; only two cases of multifocal choroid plexus metastases have been reported to date.

OBSERVATIONS

The authors report the third case of multifocal metastases to the choroid plexus, that of a 75-year-old man who developed three measurable choroid plexus lesions approximately 3.5 years after undergoing total thyroidectomy and chemotherapy for papillary thyroid carcinoma. He underwent intraventricular biopsy of the largest lesion and subsequently died of hydrocephalus after opting for comfort care only.

LESSONS

This is the third case of multifocal choroid plexus metastasis in the literature and the second case of multifocal metastasis from thyroid carcinoma. As such, the natural disease course is not well characterized. This case is compared with the previous eight reports of choroid plexus metastases from thyroid carcinoma, seven of which involved solitary lesions. The eight prior cases are evaluated with attention to treatment modalities used and factors potentially influencing prognosis, specifically those that might contribute to hydrocephalus, a reported complication for this pathology.

Metastatic cerebellar tumor of papillary thyroid carcinoma mimicking cerebellar hemangioblastoma

INTRODUCTION

Well-differentiated papillary thyroid carcinoma generally (PTC) have a favorable prognosis. This metastasis is rare in the central nervous system. Brain metastasis has a relatively poor prognosis. We present a rare case of cerebellar metastasis, one that mimics a solid type cerebellar hemangioblastoma and because of which it was very hard to reach accurate preoperative diagnosis. Accurate diagnosis was challenging because of the similar imaging and histopathological findings for these two tumors.

CASE DESCRIPTION

A brain lesion was detected by routine medical checkup of the brain with MRI in a 49-year-old woman 2 years after thyroidectomy for well-differentiated PTC. Gadolinium-enhanced MRI showed a homogeneous prominently enhanced lesion with surrounding enhanced dilated vessels in the left cerebellar hemisphere. Digital subtraction angiography showed a strongly stained lesion fed by the peripheral branch of the left posterior inferior cerebellar artery with drainage into the inferior vermian vein, revealing arteriovenous shunting. The most like likely preoperative diagnosis was felt to be that of a solid cerebellar hemangioblastoma. Gross total resection of the tumor was achieved by bilateral suboccipital craniotomy, and intraoperative pathological analysis suggested hemangioblastoma. Histopathological findings showed proliferation of vacuolated sheeted tumor cells with clear and eosinophilic cytoplasm and numerous thin-walled microvessels, consistent with hemangioblastoma. However, the final diagnosis was brain metastasis of the follicular variant of PTC due to a partial thyroid follicle-like pattern including eosinophilic fluid pathologically and positive TTF-1 immunostaining.

DISCUSSION AND EVALUATION

Since presented rare case of cerebellar metastasis of PTC was very similar to solid type cerebellar hemangioblastoma on imaging and histopathological findings, accurate diagnosis was challenging. Moreover, it is extremely rare for a cerebellar metastasis to occur as an initial distant metastasis of PTC, and hemangioblastoma is the most common primary cerebellar neoplasm in adults. This epidemiological data was also one of the reason of difficulty to reach preoperative accurate diagnosis.

CONCLUSIONS

To the best of our knowledge, there are no other reports of challenging diagnosis case of these two tumors in the literature. Brain metastasis of a well-differentiated PTC could be a relatively poor prognostic factor, and accurate diagnosis and suitable surgical therapy or radiotherapy are needed.