Children with multiple endocrine neoplasia type 2B: Not tall and marfanoid, but short with normal body proportions

OBJECTIVE: Multiple endocrine neoplasia 2B (MEN2B) is characterised by early‐onset medullary thyroid carcinoma (MTC), pheochromocytoma and several nonendocrine manifestations. Unfortunately, MEN2B is often diagnosed late, after the development of clinically significant MTC. Marfanoid habitus is considered an important related feature, which may lead to the assumption that patients with MEN2B have tall stature. Here, we describe the longitudinal growth and body proportions of eight MEN2B patients during childhood. DESIGN: It is a retrospective case series. METHODS: Patients were under the care of a Dutch MEN expertise centre. Growth patterns were assessed and interpreted in relation to body mass index (BMI), age at diagnosis and at thyroidectomy, extensiveness of disease manifestations and parental height. RESULTS: Seven patients were short during childhood, of whom four showed growth below target height range (THR) and three at the lowest margin of THR. Only one patient grew well within THR. All patients who attained final height (n = 4) ended within THR, despite short stature during childhood. Arm span/height ratio was not increased and upper segment/lower segment ratio was not reduced in any patient. Short stature in childhood in this study did not seem to be associated with age at diagnosis, age at thyroidectomy, extensiveness of MTC, endocrine deficiencies or BMI. CONCLUSIONS: This study shows that children with MEN2B may well present with short rather than tall stature. Thereafter, final height within THR was attained in those who already reached adulthood, but none had tall stature. Finally, body proportions were normal in all children and adults in this case series, not underlining a ‘marfanoid’ body habitus.