It is best characterised in humans. They are autosomal dominant disorders, but sporadic forms occur.
Distinct syndromes occur.
Carcinoid tumours of the lung, thymus, and gastrointestinal system may also be are present. This is a syndrome of C-cell carcinoma, phaeochromocytoma, with or without multiple mucosal neuromas. These are overlap syndromes where there are mixtures of the above conditions. Multiple endocrine neoplasia is rare in animals. Multiple endocrine neoplasia syndromes revisited.