Diffuse large B-cell lymphoma presenting osteolytic bone lesions and hypercalcemia.

A case of B-cell lymphoma with multiple osteolytic lesions, marked hypercalcemia and paraprotein of IgMκ type, was reported. The patient was a 53-year-old male, who was admitted to our hospital in July, 1988, because of back pain. On physical examination, generalized lymphadenopathy and an abdominal large mass (φ15cm) were observed. Lymph node biopsy revealed diffuse large cell lymphoma (LSG criteria) which was classified as B-cell type. Systemic bone roentrgenological examinations demonstrated multiple lytic lesions, including punched-out lesions, although bone scintigraphy (99mTc-MDP) was negative. Marked hypercalcemia (15.6mg/dl), elevated level of serum LDH (4070U/1), and IgMκ paraproteinemia were also observed. Atypical large lymphoid cells were seen in bone marrow. Consequently, the clinical stage was determind to be IV (Ann Arbor classification). The patient was treated with elcatonin, dexamethasone, and hydration, and then with CHOP therapy. The serum calcium level returned to normal, and lymphadenopathy and the abdominal mass regressed. However, the lymphoma was reflactory to further treatment and the patient died of septicemia.In order to investigate osteoclast activating factor (OAF) in this case, parathyroid hormone (PTH), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were measured. The levels of PTH and TNF-α remained within normal ranges throughout the course. The serum IL-1β level was slightly higher (0.27ng/ml) than normal (<0.2ng/ml) at the initiation of the treatment, and returned to the normal range after CHOP therapy. The serum IL-1β level remained normal, even when the patient developed septicemia. It is suggested that IL-1β plays a role as an OAF in the osteolytic mechanism and hypercalcemia.