ABSTRACT
Malignant infantile osteopetrosis [MIOP] presents early in life with extreme sclerosis of the skeleton and reduction of bone marrow spaces. Since there is a defect in the bone marrow, the disease can cause anemia, extramedullary hematopoiesis secondary to anemia leading to hepatosplenomegaly, cranial nerves compression and severe growth failure. This disorder is often lethal within the first decade of life because of secondary infections. Stem cell transplantation [SCT] remains the only curative therapy. We report a two-month old male infant, diagnosed as MIOP while investigating the cause of hepatosplenomegaly. The patient was referred for stem cell transplantation. Malignant infantile osteopetrosis should be kept in mind as a rare cause of hepatosplenomegaly and the patient should be referred for stem cell transplantation before neurologic or visual impairment develops