Skeletal manifestations in cutaneous T-cell lymphomas

The clinical course of three patients with cutaneous T-cell lymphoma (CTCL) in whom skeletal disease developed is presented and the literature on skeletal involvement in these disorders is reviewed. Three separate types of skeletal manifestations occurred: (1) osteolytic lesions, (2) osteoblastic lesions, and (3) diffuse osteoporosis. Hypercalcemia was present in two cases. Tumor cells from two patients in short-term culture secreted osteoclast-activating factor(s). Both of these patients had pathologic evidence of osteoclast activation in bone sections. Thus, the tumor cells in certain patients with CTCL may derive from a monoclonal proliferation of a T-cell subset capable of producing humoral bone-resorbing factor(s) similar to those demonstrated in cultures of mitogen- and antigen-activated normal lymphocytes. Since skeletal lesions are unusual, it would follow that other T-cell subsets account for pathologic cell proliferation in most patients with CTCL.