# Coexisting Graves' Disease and Papillary Thyroid Carcinoma: The Importance of Nodule Surveillance in Autoimmune Hyperthyroidism

## TL;DR

A patient with Graves' disease had a thyroid nodule that turned out to be cancer, highlighting the need for regular thyroid checks in such cases.

## Contribution

Demonstrates the importance of nodule surveillance in Graves' disease using a multimodal diagnostic approach.

## Key findings

- A thyroid nodule in Graves' disease grew and was found to be papillary thyroid carcinoma.
- Molecular analysis identified a rare BRAF mutation with high malignancy probability.
- Early detection through surveillance led to successful treatment and no major complications.

## Abstract

Graves' disease (GD) is an autoimmune disorder characterized by hyperthyroidism and is commonly associated with diffuse thyroid enlargement. The coexistence of thyroid nodules in GD presents diagnostic and management challenges, particularly when malignancy is a concern. We report a 44-year-old woman with asymptomatic biochemical hyperthyroidism detected during routine screening. Initial ultrasound revealed a subcentimeter right thyroid nodule (TI-RADS TR4), for which surveillance was recommended. Follow-up imaging demonstrated interval growth, prompting fine-needle aspiration that was suspicious for papillary thyroid carcinoma (PTC) (Bethesda V). Molecular analysis revealed a rare BRAF mutation with an estimated ~70% probability of malignancy. The patient underwent total thyroidectomy with central neck dissection, confirming a 1.1 cm classic PTC with microscopic nodal metastasis (pT1bN1a). She recovered uneventfully and remains under endocrinology follow-up. This case underscores the importance of structured ultrasound surveillance in patients with GD, even in the absence of clinical symptoms. A multimodal diagnostic approach incorporating imaging, cytology, and molecular analysis can facilitate early detection and informed risk stratification, supporting timely and appropriate management.