S007

Gravesí patients may harbour sinister pathology.

N Rashid1, G Kocjan2, Jay A2 ,Tim Beale3, T T Chung1.
Department of Endocrinology1, Department of Cellular Pathology2, Department of Radiology
3.University College London Hospitals.

250 Euston Road, London, NW1 2BU

Introduction

Graves' disease is the most common cause of hyperthyroidism. Whilst the association of papillary thyroid cancer and lymphocytic thyroiditis is well documented, the occurrence of papillary carcinoma in a known Gravesí disease patient is rare, especially in the absence of nodular thyroid disease.

Case history

A 30 year old female patient with a past medical history of PCOS was diagnosed with Gravesí disease fifteen months ago. She had clinical and biochemical evidence of hyperthyroidism and associated opthalmopathy. Propylthiouracil alone failed to improve her thyroid profile, necessitating a block and replace regimen with carbimazole and thyroxine. Sub-total thyroidectomy was recommended as definitive treatment for her difficult to control Gravesí disease. Her eye condition so far has responded only partially to high dose steroids and orbital radiotherapy.

Investigations:

On presentation to the emergency department, a thyroid ultrasound was requested and showed no focal nodules but a heterogeneous area <1cm containing small echogenic foci in left lobe. A repeat scan was recommended.

Interval thyroid ultrasound seven months later showed reduction in size of gland but no changes in the comparative heterogeneous area and FNA was performed.

Results and treatment

Thyroid FNAc was suspicious of papillary carcinoma (THY4).† A definitive diagnosis of papillary carcinoma could not be made because of the unusual coexistence of features of Gravesí disease. A completion thyroidectomy was performed.

Histology of isthmic nodule confirmed follicular variant of papillary carcinoma. It measured 0.8cm but multifocal and sub-capsular extension to left lobe measuring on aggregate an additional 3mm (pt1N0M0). This is DTC stage 1 carcinoma with 10 years mortality risk of 1.7%.

Conclusion and points for discussion

1)    The case illustrates the rare co-occurrence of Gravesí disease and papillary thyroid carcinoma. Ultrasound scan and FNA contributed to the final diagnosis and are the recommended investigations for persistent heterogeneous nodules, despite the presence of Gravesí disease.

2)    Severe Gravesí opthalmopathy is a relative contraindication for radio-iodine therapy.† In view of histology proven multifocal papillary thyroid carcinoma, it is debatable if radio-iodine ablation is necessary in this case.