I am not able to make a specific diagnosis based on the information that you present. Episodic hypertension can be seen in other situations than pheochromocytoma. For example, ischemic heart disease can present with episodes of hypertension. We also see episodic hypertension with certain cold medications and nasal sprays. We see episodic hypertension with emotional disorders such as panic disorder and acute anxiety. We also see episodic hypertension with carcinoid syndrome and diabetes or Parkinsonism with autonomic neuropathy. I cannot provide a diagnosis for the small masses in your kidney. I am not sure how they could contribute to episodes of hypertension.
I can only suggest that you continue to consult with your physicians and have ongoing monitoring of your blood pressure.