Based on our cohort previously screened on morphological features and by FH IHC, we now analyzed 13 FH deficient ULs with available tumor DNA by targeted panel sequencing to investigate their somatic variant spectrum for both small genetic (single nucleotide variants: SNVs, base insertions or deletions: indels) and copy number variants (CNVs) and additionally characterized these ULs by RB1 IHC. The gene discussed is RB1; the disease is familial hyperaldosteronism.