Classic Hodgkin lymphoma with initial extranodal osseous presentation: a case report and literature review.

Initial extranodal osseous presentation of Classic Hodgkin lymphoma (CHL) is extremely rare. The present study describes a case of CHL in an 11-year-old male presenting with lower back and right hip pain. Radiologic imaging showed a solitary lytic lesion involving the L5 vertebrae and sacrum. Pathologic examination led to a diagnosis of extranodal osseous CHL and further workup proved bone marrow and nodal disease. Diagnosis of extranodal osseous CHL is challenging, especially in this age group and location. When confronted with a solitary lytic bone lesion in a young patient, more common benign and neoplastic entities enter the differential diagnosis and include osteomyelitis, Langerhans cell histiocytosis, epithelioid hemangioma of bone, leukemia, and anaplastic large cell lymphoma (ALCL) among others, with extranodal osseous CHL being one of the less common entities in the differential diagnosis. This case report raises the awareness of extranodal osseous CHL as one of the entities to consider when confronted with a solitary lytic bone lesion in a young patient.