Multiple endocrine neoplasia 2A with RET mutation p.Cys611Tyr: A case report.

Rationale: Multiple endocrine neoplasia 2A (MEN2A) is a rare autosomal-dominant genetic syndrome, frequently misdiagnosed or neglected clinically, resulting in delayed therapy to patients.

Patient Concerns: A 47-year-old Chinese male patient underwent laparoscopic right adrenal tumorectomy, and postoperative pathology confirmed the tumor as pheochromocytoma (PHEO). He was readmitted to the department of endocrinology and metabolism due to constant increase in carcinoembryonic antigen (CEA) at 5 months after the operation.

Diagnosis: The patient was confirmed with medullary thyroid carcinoma (MTC), multiple neck lymph node metastasis, and pituitary microadenoma. The p.Cys611Tyr (c.1832G>A, C611Y) mutation was detected. Therefore, he was diagnosed with MEN2A.

Interventions: He underwent total thyroidectomy. The gene-sequencing analysis of his family was conducted, and the C611Y mutation was detected in his daughter.

Outcomes: The level of carcinoembryonic antigen decreased significantly after thyroidectomy in this patient. Long-term follow-up management was conducted. Elevated serum calcitonin and bilateral thyroid nodules were found in his 13-year-old daughter. Thus, MEN2A was highly suspected and she was suggested to undergo total thyroidectomy.

Conclusion: Patients with MEN2A should be screened regularly and managed by a multidisciplinary team.