Endocrine Abstracts

Introduction: Multiple Endocrine Neoplasia Syndrome 2B (MEN 2B) is a very rare genetic disorder which affects the thyroid and the adrenal glands, the development of mucosal neuromas and the general appearance of the patient’s body. Therefore, we can encounter Medullary Thyroid Carcinomas (MTC), adrenal sympathetic paragangliomas (or Pheochromocytomas) and habitus Marfanoid. The disease represents a challenge for every clinician, especially if it occurs in a child.

Methods: Clinical exam, Blood work, CT scan, genetic testing, pathology exam.

Case report: We present the case of a 12-year-old girl who came in the Pediatric Endocrinology Department with a right thyroid solid mass, for which she was admitted. Upon clinical examination, the patient was thin and tall, with flexible joints, suggesting Marfanoid habitus and also mucosal neuromas were found in the oral cavity, with normal blood pressure, no palpitations, no sweating. No significant family history was discovered. Thus, MEN 2B syndrome was a possible diagnosis. The general blood work and thyroid function were normal, calcitonin was 1100 times over the upper normal limit, while serum PTH and urinary metanephrines and normetanephrines in the 24 h sample urine were within normal range. We also performed a thyroid ultrasonography which revealed 2 hypoechoic nodules in each thyroid lobe, with macrocalcifications. We performed a CT scan which showed the 2 nodules, with no lymphatic nodes suggesting metastases. The patient underwent a total thyroidectomy with bilateral cervical lymph node dissection. The pathology report came back positive for MTC in both nodules, with no extension to the lymph nodes, confirming our diagnosis of MEN 2B. The next step was genetic testing from the patient’s blood to identify if she had the germinal mutation of the RET gene, which came back positive for the p.Met918Thr in exon 16. Obviously, we had to test the patient’s parents and brother and there were all negative for the mutation.

Discussions: The patient was brought to us because of a thyroid nodule which turned out to be a MEN 2B syndrome with bilateral MTC, mucosal neuromas and Marfanoid habitus, without the implication of the adrenal glands, with a de novo mutation of the RET gene. The fact that it was discovered in a child makes it even more rare.

Conclusions: MEN 2B Syndrome is a very rare genetic disorder in the general population, making it even more unexpected to be found in the case of a child.