Small cell carcinoma of the thyroid gland with a solid brain metastasis detected by F-18-FDG PET/CT

Excerpt

A 77-year-old man underwent fine needle aspiration biopsy of a 3.5 cm nodule of the right thyroid lobe. Cytology showed small cells with scant cytoplasm; on immunocytochemistry, the cells showed high proliferative activity and cytoplasmic expression for neuroendocrine marker synaptophysin. These findings were suggestive for a small cell carcinoma of the thyroid gland. Therefore, the patient underwent fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) for staging. PET/CT showed an area of increased F-18-FDG uptake corresponding to the right thyroid nodule (Fig. 1a, b). Furthermore, an area of increased radiopharmaceutical uptake was detected in the brain, corresponding to a lesion located in the left parietal lobe on low-dose CT (Fig. 1a, c). Biopsy of the brain lesion was suggestive for small cell carcinoma. The final diagnosis based on pathology and F-18-FDG PET/CT findings was small cell carcinoma of the thyroid gland with brain metastasis. The patient was addressed to chemotherapy and radiation therapy, but he died 6 months after the begin of therapy for disease progression.

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