Endocrine Abstracts

Introduction: Neurofibromatosis type 1 (NF1) is a rare autosomal dominant disease. Patients affected by NF1 have an increased risk of developing tumors other than neurofibromas, especially of endocrine origin, that’s why this patients should be screened for endocrine lesions. In this report, we describe a patient affected by NF1 who present a thyroid nodule.

Observation: A 27-year-old woman was admitted in our department for endocrinological evaluations of NF1. She had a family history of NF1, primary hyperthyroidism and autoimmune diseases. The diagnosis of NF1 was made at the age of 3 months when the first skin lesions appeared on her trunk. Her follow-up was irregular. She had cervicobrachial neuralgia revealing bilateral plexiform neurofibroma in the cervical, dorsal, and lumbar region and a suspicious lateral vertebral mass regarding C6 and C7 vertebrae on spine MRI. Bilateral mammary and axillary neurofibromas are found on mammography. On fundus examination, she presented with Lisch nodules without choroidal nodules. She also suffers from chronic gastritis with duodenal polyp on esophagogastroduodenoscopy. The patient had a normal growth and puberty. She was normotensive, plasma methoxylated derivatives and phosphocalcic assessment were normal. She had a grade 1 goiter, with a normal TSH level at 2.15 mIU/l [0,25 - 4,5] and FT4 at 13,7 ng/l [9 - 18]. Anti-thyroid peroxidase and anti-thyroglobulin antibodies were negative. Cervical ultrasound showed initially a multicystic goiter. Two years later, cervical ultrasound identified one right and one left thyroid nodules respectively of 15 x 9 mm and 8 x 5 mm classified as EUTIRADS 3.

Discussion: NF1 is a common heritable neurocutaneous disorder. Central nervous system tumors, pheochromocytoma and optic nerve glioma are known to be associated with NF1. Thyroid nodular disease seems to be underestimated. In literature, there is few cases reporting the presence of thyroid neurofibroma, its possible transformation and even papillary thyroid carcinoma in patients with NF1. These finding highlight the importance of developing a guideline for the screening of thyroid diseases in these patients.