A Case of Papillary Thyroid Cancer Presenting with a Cystic Solitary Brain Metastasis

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 459-496-Thyroid Neoplasia & Case Reports
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-483
Akankasha Goyal*1, Salil Debendra Sarkar2, Roxanne Todor3 and Ulrich K Schubart4
1Montefiore Medical Center, New York, NY, 2Jacobi Med Ctr, Riverdale, NY, 3Jacobi Medical Center, Albert Einstein College of Medicine, 4Jacobi Medical Center, Albert Einstein College of Medicine, Bronx, NY
Background: We describe a case of metastatic papillary thyroid cancer with a cystic solitary brain metastasis at initial presentation.  This is a very rare scenario and there are no established therapeutic guidelines for treating brain metastases from thyroid carcinoma.  

Clinical Case:
A 47 year-old man presented to the emergency room after an episode of dizziness and fall from a ladder.  A  CT of the head and neck, performed to evaluate for traumatic injury, revealed a large cystic lesion in the right frontal lobe with an intramural enhancing nodule.  Neck exam revealed thyromegaly and enlarged anterior neck lymph nodes (LN).  Fine needle aspiration biopsy of an enlarged LN showed moderately differentiated papillary thyroid carcinoma (PTC).  On brain MRI the lesion was thought to be most consistent with a pilocytic astrocytoma or benign glioma.  The patient underwent total thyroidectomy and lateral neck dissection, which yielded multifocal, bilateral classical and follicular variant PTC with 11 metastatic cervical LN.  Four weeks postoperatively, whole body I-131 imaging showed a focus of uptake in the right frontal lobe, corresponding to the nodule within the cystic lesion seen on brain MRI. The patient underwent a right fronto-temporal craniotomy with an ultrasound- guided cyst drainage and microsurgical tumor excision.  Pathology was consistent with metastatic PTC, follicular variant.  Brain cyst fluid thyroglobulin (Tg) level was > 30,000 ug/L [reference serum Tg 0.83-68 ug/L]. Four weeks later 9.55 GBq of I-131 were administered therapeutically. Now at two months post craniotomy, the patient remains without neurological symptoms.  He is maintained on levothyroxine with a suppressed TSH.

This is a unique case of a solitary, cystic, radioiodine-avid intra-cerebral metastasis from PTC, treated with surgery and I-131 therapy.  The cystic lesion seen on imaging can be easily confused with an intracranial glioma.  The possibility of metastatic PTC should be considered in the appropriate clinical setting. Whole body I-131 scanning and measurement of Tg in aspirated cyst fluid can confirm the diagnosis.  Limited available evidence suggests that surgical resection of brain metastases, as opposed to RAI or external radiation therapy alone, improves survival.1,2

1. Chiu et al JCEM 1997;82:3637-3642 2. Salvati et al J Neuro-Oncology 2001;51: 33-40

Nothing to Disclose: AG, SDS, RT, UKS

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