ESPE Abstracts

Objective: To summarize the clinical features and genetic characteristics of a patient with multiple endocrine neoplasia type 2B (MEN2B) and to review the literatures.

Methods: We summarized clinical features, gene sequencing result, treatment and prognosis of a child suffered with MEN2B who was admitted to the Department of Pediatrics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine in February 2016. And we also searched for relevant cases through the medical literature databases such as Pubmed, Wangfang and so on in order to generalize characters of this rare disease.

Results: The patient had difficulty in defecation soon after birth. Neck masses were noticed when she was 9 and grew progressively. Multiple neuromas were found in the gums, tongue and cheek mucosa when she was admitted in our hospital at the age of 12. Many hard nodules were palpable in her thyroid. Serum calcitonin level was significantly elevated. Bilateral thyroid cancer with cervical lymph node metastasis was suspicious when using ultrasound. Next-generation sequencing showed the proband had a heterozygous mutation in RET proto-oncogene (c. T2753C; p. M918T). Then thyroid cancer extended radical mastectomy + radical neck dissection were performed in her. Bilateral medullary thyroid carcinoma (MTC) was verified by thyroid pathology. 6 months after the first operation, she was taken mediastinal lymph node dissection because of mediastinal metastases occurring. Calcitonin was still higher than normal in the current follow-up. MEN2B was very rare and only 20 cases have been reported in China. Few was diagnosed during childhood.

Conclusion: Hirschsprung disease with thyroid mass is a clue to screen MEN2B, which is caused by RET mutation. Certain mutation (p. M918T) can cause MTC definitively.