Medicare denials for benign lesions

Our office had 2 recent surgery claims partially denied by Medicare. Each were for a benign lesion & closure and each were not billed until pathology report was received so the DX code used was taken directly from the path report. In each case we received payment for the closure but none for the excision. In both cases the reason code given was CO-50: “These are non-covered services because this is not deemed a ‘medical necessity’ by the payer. Note: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.” Below is what appears on the EOB as well as the DX codes used. Is it merely the DX code used & can they be appealed with documentation attached? Any insights into what the issue(s) may be concerning payment would be appreciated. Thank you.

Case #1

11404 DX L91.8 (per path report) not paid
12032 DX L91.8 (per path report) paid


Case #2

11401 DX L73.9 (per path report) not paid
12031 DX L73.9 (per path report) paid