Ki-1 positive large cell anaplastic lymphoma: multiple bone lytic lesions and interleukin-6.

Ki-1-positive large cell anaplastic lymphoma (Ki-1 LCAL) is recognized as a clinicopathologic syndrome with fever, peripheral lymphadenopathy and cutaneous nodules; the neoplastic cells express Hodgkin's disease-associated antigen, Ki-1 (CD30). We review here a recent case of Ki-1 LCAL with multiple bone lesions with destruction and present additional information. Although bone absorption is reported in some cases of Ki-1 LCAL, the genesis of bone absorption is unclear. Interleukin-6 (IL-6) is an important regulator of osteoclast formation and activation and can induce bone absorption. In our case, the surgically removed tumor tissue was studied for IL-6 mRNA expression and IL-6 secretion without any stimulation. Northern blot analysis showed strong IL-6 mRNA expression in the tumor tissue and ELISA assay showed a large amount of IL-6 in culture supernatants of the tumor tissue. Based on these results, coupled with the reported evidence, we discuss the close relationship between the presence of osteolytic lesions and IL-6 production in Ki-1 LCAL.