Hypertrophic osteoarthropathy in metastatic renal cell carcinoma

Clinical signs of hypertrophic osteoarthropathy developed in a thirty-eight-year-old man with metastatic hypernephroma. Roentgenograms of the extremities detected the characteristic periosteal reaction along the radius, ulna, metacarpals, femur, tibia, and fibula, bilaterally. The pathogenesis of this syndrome is unknown; it appears to be mediated by a pathologic reflex with the vagus nerve as the afferent limb. When seen in patients with renal cell carcinoma, hypertrophic osteoarthropathy may herald the development of intrathoracic metastases.