“…5 Some patients may rarely present a paraneoplastic syndrome, Hypertrophic osteoarthropathy (HOA), a condition characterized by digital clubbing, periostitis of long tubular bones, polyarthralgia and synovial effusion, most prominent in the large joints. 3,7,8 OAH can be classified in primary, when it's not associated with any medical condition; and secondary, which can be divided into pulmonary causes such as cystic fibrosis, primary or metastatic carcinoma, and non-lung, such as cyanotic congenital heart disease, liver cirrhosis, intestinal polyps, among other pathologies. 3,7 Although the pathophysiology of HOA remains controversial, there are two different theories attempting to explain it.…”