ESPE Abstracts

Background: Multiple endocrine neoplasia type 2B (MEN 2B) is a rare endocrine disease associated with early and aggressive medullary thyroid carcinoma (MTC), pheochromocytoma and several non-endocrine manifestations. MEN 2B is often diagnosed late, when symptomatic thyroid disease is present. Recognition of early, often non-endocrine, manifestations is elemental and may lead to early intervention through early diagnosis. However, early recognition is complicated by both the broad clinical spectrum of manifestations and rareness of MEN 2B.

Objective: The aim of this study is to describe disease presentation, subsequent manifestations and outcome in a MEN 2B cohort and to aid in increasing awareness for early symptoms.

Methods: A retrospective single-center cohort study was conducted at the University Medical Center Utrecht, a tertiary referral and national expertise-center for MEN-patients. All MEN 2B patients in follow-up between 1990 and 2017 were included and medical records were reviewed.

Results: Eight patients (3 males, 5 females) were identified, all had a de novo RET-mutation (Met918Thr). MEN 2B in this cohort most often presented with neonatal gastro-intestinal symptoms (50%), as well as with mucosal neuromas (38%) or delayed motor development (38%); not with symptomatic MTC. Thyroidectomy cured or prevented thyroid disease in 50% of patients. Patients operated at young age (<1 year) have remained free of disease. Pheochromocytoma was detected in 2; the youngest patient presenting at an age of 16 years. All patients suffered from intestinal problems, most commonly severe and chronic obstipation which severely impacts daily life. Other common non-endocrine manifestations, which might help to raise suspicion of MEN-2B, were oral and ocular neuromas, ‘hypertrophic bumpy lips’, central diastemas as well as less specific symptoms such as joint hyperlaxity and a marfanoid body habitus.

Conclusion: Awareness among clinicians of symptoms of MEN 2B is important, as early diagnosis of MEN 2B is associated with still curable thyroid disease. Neonatal gastro-intestinal manifestations may offer a window of opportunity for early detection of MEN 2B, as rectal biopsies can show diffuse intestinal ganglioneuromatosis, strongly pointing to a diagnosis of MEN 2B. In addition, other non-endocrine manifestations can be the first detectable sign of MEN 2B. Therefore, these symptoms are important to recognize as they can be the clue for an early diagnosis of MEN 2B.