Bone within a Bone: Unravelling a Rare Case with an Unusual Co-Existence

Abstract

Background: a well known radiological finding “bone within a bone” isseen in a variety of conditions of which ‘Osteopetrosis’ is one. “Osteopetrosis of infantile origin” is one of its rare and aggressive subtypes which is inherited as autosomal recessive and often leads to death due to recurrent infections and multi system involvement. Case presentation: A 2 year male child presented with fever, loose stools and gum bleeding since 2 days with regression of milestones. There was past history of blood transfusion and two sibling male deaths in the family. Examination revealed severe malnutrition with significantly enlarged lymph nodes and hepatosplenomegaly. All necessary investigations sent revealed pancytopenia with ‘atypical cells’, deranged kidney function test and transaminitis. Pathognomic finding of “bone within a bone” was seen on X-ray. Child succumbed to death due to severe sepsis despite the treatment. Discussion: Increased bone density in osteopetrosis causes encroachment of marrow space leading to all other consequences. Children diagnosed in early infancy often succumb to death due to severe sepsis. Its definitive treatment is not found yet but Hematopoietic Stem Cell Transplant (HSCT) is thought to be a potential cure and is still under research. Conclusion: Malignant infantile osteopetrosis is a rare but fatal condition and its resemblance to other disease conditions often masks the diagnosis. Creating awareness about osteopetrosis along with genetic counselling and antenatal diagnosis plays important role in managing it. Although rare, its co-existence with lymphoma should always be ruled out.