Classic Hodgkin lymphoma with osseous involvement mimicking Langerhans cell histiocytosis in a child.

Hodgkin lymphoma (HL) commonly presents superficial lymphadenopathy. In addition, HL cells can arise in various organs including the liver and spleen as an extranodal lymphoma. HL in bone is unusual at the initial diagnosis, although some cases show late-stage localization of lymphoma cells to bone. We report the rare case of a young patient with cranial bone classic HL, presumably originating from the skull without any involvement of lymph nodes. As the main clinical manifestation was only tumor mass in the skull without osteoscopic pain, the tentative diagnosis of Langerhans cell histiocytosis was histologically confirmed by an excisional biopsy. Before the final pathological diagnosis as classic HL, we noticed several small lesions in extranodal regions through systemic surveys, suggesting that the cranial lesion appeared antecedent to those lesions. This is a rare and instructive case of cranial bone HL for which a histological diagnosis has been meticulously made.