Bone marrow involvement is rare in patients with Hodgkin lymphoma (HL). Its incidence varies with respect to risk factors from 4% to 14%. Low risk patients do not need trephine biopsy according to some research. In the era of positron emission tomography/computed tomography (PET/CT) staging prior to therapy, the role of trephine biopsy as a part of staging procedures becomes debatable. Many institutions worldwide created their own guidelines in the application of trephine biopsy in staging of the (HL) patients. Our institution prefers performing trephine biopsy in all risk group patients, except those who underwent PET/CT staging before therapy and if no active bone sites were found. Most of our patients are staged using multislice computed tomography (MSCT) and we perform PET/CT in the follow up after completing the induction protocol. That is why we propose the trephine biopsy to the most of our patients. A Greek group of authors have derived a clinical prediction rule for the possibility of the bone marrow involvement, which is named the Z score (Zs), and if it is ≥10, patients are at high risk for bone marrow involvement. We present a case of a neglected, advanced (HL) patient, with the defined high risk for bone marrow involvement (Zs=25). He was clinically suspected to have affected bone marrow, which was later histologically confirmed. Unilateral trephine biopsy was performed. Infiltracija koštane srži kod bolesnika sa Hočkinovim limfomom (HL) je retka. Incidencija varira u zavisnosti od faktora rizika od 4% do 14%. Niskorizični bolesnici nemaju potrebe za biopsijom koštane srži, što pokazuju neka istraživanja. U eri PET/CT stadiranja pre primene terapije, potreba za biopsijom koštane srži, kao deo stadiranja HL, postaje diskutabilna. Mnoge ustanove u svetu imaju svoje sopstvene vodiče za biopsiju koštane srži u toku stadiranja HL. Naša ustanova ima mogućnosti da sprovodi biopsiju koštane srži bolesnicima svih rizičnih grupa, sem onih koji imaju urađen PET/CT pre početka uvodne terapije i ukoliko nisu detektovani aktivni koštani fokusi. Kod većine naših bolesnika stadijum bolesti se određuje primenom MSCT-a, dok PET/CT sprovodimo u praćenju terapijskog odgovora nakon završetka indukcionog protokola. Grčka grupa autora razvila je kliničku predikcijsku šemu za mogućnost infiltracije koštane srži, koju su nazvali Z skor (Zs), čija vrednost ≥10 ukazuje da bolesnici imaju visok rizik za infiltraciju koštane srži. Prezentujemo slučaj bolesnika sa zapuštenim, uznapredovalim HL, sa definisanim visokim rizikom za infiltraciju koštane srži, Zs je bio 25. Kod bolesnika je postojala klinička sumnja na infiltraciju koštane srži koja je kasnije i patohistološki potvrđena. Primenjena je unilateralna biopsija.