What conditions are associated with pheochromocytomas?  

Thyroid and others. 9 of 10 pheochromocytomas are sporadic - that means they occur for no obvious reason. The other 10 percent are caused by rare familial syndromes (men syndromes). Men 2, for example, is almost always associated with thyroid cancer, and 1/5 have a parathyroid problem, as well.