Hypertrophic pulmonary osteoarthropathy associated with disease progression in renal cell carcinoma.

Hypertrophic osteoarthropathy (HOA) is a paraneoplastic syndrome characterized by periosteal formation and arthritis and usually accompanied by clubbing ofthe digits. Many malignancies have been associated with HOA/clubbing, most being lung cancer and lung metastatic cancer. We herein present a 53-year-old man with lung metastasis from renal cell carcinoma (RCC). HOA occurred one year after the metastasis. Reviewing the literature, only five cases of RCC with HOA have been reported. If their clinical history was traceable, they consistently had disease progression. We reviewed the pathogenesis of HOA/clubbing and linked the prognosis of RCC to relevant cytokines. Therefore, HOA not only heralds a progression of disease but suggests a probable therapeutic choice by targeting some cytokines.