Knee Monoarthritis Signals Lung Cancer in Some Patients
Italian researchers find cancer in five cases out of 296 patients with knee problem
FRIDAY, Sept. 7 (HealthDay News) -- In some patients, monoarthritis of the knee may be a warning sign of non-small cell lung cancer, according to research published online Sept. 3 in the Annals of the Rheumatic Diseases.
Fabrizio Cantini, M.D., of the Hospital Misericordia a Dolce in Prato, Italy, and colleagues reviewed the clinical records of 296 patients who presented with isolated monoarthritis of the knee. In five of these patients (1.7 percent), the arthritis was the first symptom of occult non-small cell lung cancer, according to the authors. The malignancies were diagnosed through X-ray, chest computed tomography and biopsy.
Knee monoarthritis may represent a paraneoplastic syndrome. A variety of these syndromes are associated with about 10 to 20 percent of cases of small-cell lung cancer. They occur less frequently with non-small cell lung cancer, but hypertrophic osteoarthropathy is associated with about 5 percent of patients.
"In our experience, this paraneoplastic condition should be suspected in all heavy smokers, HLA-B27 negative, who present with mild to moderate isolated knee monoarthritis in the absence of a clear history of psoriasis or spondyloarthropathy, and of radiological features suggestive of severe osteoarthritis or chondrocalcinosis," the authors write. "Although not frequent, awareness of the main clinical characteristics of this manifestation may help to facilitate proper diagnosis."