Cat with chronic vomiting

Sayed, 10-year-old male neutered persian,  was presented with acute onset of vomiting about 10 days ago. He was BAR at the time of presentation with normal abdominal palpation and normal X-Ray findings. The cat became fine with symptomatic treatment with cerenia and gastro food. Now, whenever the owner shifts the cat to the old food, he starts vomiting again. I did the abdominal US today to see if there was any evidence of IBD. Some jejunal loops were thickened. But there were some incidental findings. Liver parenchyma showed several cysts and both kidneys showed cysts as well. Blood test was done and all the values were within the normal limits. ALT was also normal. Now the questions is: if these cystic structures could be tumor? and should we proceed with hepatic biopsy/FNA?. The cat is clinically fine, has good appetite and is active. CBD was normal