Endocrine Abstracts

The commonest site of metastasis from papillary carcinoma is regional lymph nodes. Distant metastases are rare, most presenting synchronously. Brain metastases in papillary carcinoma are rare, reported with a frequency of 0.1–5% and cavernous sinus metastasis is extremely rare.

Case report: A 62-year-old woman presented with a history of non-secretory pituitary macroadenoma present with symptoms of hypopituitarism. MRI of the brain revealed a 4.5×3.1×3 cm, extension into the cavernous sinuse. The tumorwas not rescable, she Underwent a simple biopsy in view of the haemorrhagic nature of the tumor. Histopathology revealed a tumor with diffuse papillary architecture. On immunohistochemistry: positive for TTF1, PAX8, thyroglobulin, TPO;Ki67 (10–15%) and negative for GH, LH, FSH, ACTH, TSH. A diagnosis of metastatic papillary carcinoma was made. Thyroid ultrasound revealed two hypoechoic nodules. After thyroidectomy the histopathology was papillary micro- carcinoma thyroid-follicular variant of 05 mm. She received radioiodine therapy.

Discussion: The incidence of distant metastases from papillary carcinomas is reported to be 6–23%, the majority occurring within 5 years of the initial diagnosis. There have been case reports of papillary carcinoma with metastasis at unusual sites like the breast and cavernous sinus. All these cases were associated with a missed diagnosis of thyroid carcinoma, like our case, should be considered exceptional. There have been five reports of papillary carcinoma with metastasis to the skull base.

Conclusion: There is no consensus for the treatment of papillary thyroid carcinoma with cavernous sinus metastasis. Thus, that solitary distant metastasis from thyroidcarcinoma though rare, is a possibility, a difficult diagnosis to be made on radiology.