Bone marrow involvement in Hodgkin`s lymphoma is not rare at initial diagnosis and is associated with a poor prognosis. Atypical findings such as granuloma, eosinophilia or osteosclerosis may lead to diagnostic confusion, in which case immunohistochemistry may be helpful. We report a case of 25-year old male patient, who presented with back pain, subsequently had a mediastinal mass and was finally diagnosed as having stage IV Hodgkin`s lymphoma. Bone marrow involvement with severe osteosclerosis was found on bone marrow biopsy specimens. He received systemic chemotherapy and was discharged with improved clinical symptoms.