Abstract
Paraneoplastic polyarthritis is an inflammatory arthritis, is usually seronegative, and has a temporal and pathophysiological relationship with an underlying malignancy. Although head and neck tumors may be a cause of paraneoplastic polyarthritis, its association with tongue carcinoma has not been previously reported. We present the case of a 69-year-old man who was a former smoker and presented with polyarthritis since 2 months in the wrists, proximal interphalangeal joints, knees, and elbows, with increased levels of acute-phase reactants; negativity for rheumatoid factor, anticitrullinated cyclic peptide antibody, and antinuclear antibody; and negative results for crystals and microorganisms in the synovial fluid. Cervical computed tomography and posterior rhinoscopy were performed, which detected an asymptomatic lesion on the base of the tongue, whose biopsy was compatible with nonkeratinizing squamous cell carcinoma. Polyarthritis did not respond to glucocorticoids at medium doses (oral prednisone 20 mg/day) but progressively resolved after the initiation of antineoplastic therapy.