# Recurrent Orbital Metastases in Follicular Variant Papillary Thyroid Carcinoma After Recombinant Human Thyrotropin

## TL;DR

A patient with thyroid cancer experienced a tumor flare in the eye after treatment with a thyroid hormone drug.

## Contribution

Reports a rare case of tumor flare in follicular variant papillary thyroid carcinoma following recombinant human thyrotropin.

## Key findings

- A patient with follicular variant papillary thyroid carcinoma showed tumor flare in the orbit after rhTSH treatment.
- Orbital metastasis with intracranial extension was confirmed via imaging and biopsy.
- The case highlights potential risks of rhTSH in patients with prior metastatic disease.

## Abstract

Recombinant human thyrotropin (rhTSH) is generally well tolerated with minimal adverse effects. Symptomatic tumor expansion following rhTSH has been previously reported in the literature. Generally, these cases have involved known metastasis of aggressive variants. In this report we present a case of follicular variant papillary thyroid carcinoma (FVPTC) with recurrent treated orbital metastases and adverse response to rhTSH. Following a second dose of rhTSH, the patient reported right eye proptosis, and edema was noted on imaging. Iodine-131 scan demonstrated intense right orbital uptake with intracranial extension verified on head scans. Biopsy confirmed FVPTC and she underwent orbitotomy and enucleation. Our case illustrates the potential risk of symptomatic expansion even in cases of previously treated metastasis.