Italian to English Medical Medical (general) chest X-ray

This is from a radiografia del torace (teleradiografia telecuore -- in case this makes a difference).

The reports says "modesta congestione peribronchiale *in ilo-perilare*." It's this little "in" here that confuses me. It doesn't seem like it should be there at all, or else possibly words are missing between "in" and "ilo-perilare".

But then I think maybe I'm missing something (and why I'm posting this question), because there is a sentence in the chest X-ray right before this that says "marcata congestione del grosso interstizio peribronchiale *in ilo-perilare*." Different report, same little phrase.

I find only one instance of this online: "DISEGNO POLMONARE MARCATO, ISPESSITO, IN ILO-PERILARE E BASALE DA AMBO I LATI, PER INCREMENTO DEL PICCOLO INTERSTIZIO CHE ASSUME ASPETTO RETICOLARE."

How should I translate this?

Thanks for your help.