Association with MEN IIB Lesions arising in the setting of MEN IIB affect younger patients ( average age 15 years) and are more aggressive,
with early metastases and a 5-year survival of <5%. Patients with known MEN IIB should have a prophylactic
thyroidectomy in early childhood. The size of the tumor and.presence of metastases (which correlates with tumor
size; only 20% if <0.7 cm but 80% if> 1.5 cm) is more important for sporadic lesions and those associated with
MEN IIA. Younger patients and women also do better.