Palmar fasciitis and polyarthritis syndrome with oesophageal carcinoma: a case report and review of the literature.

A 59-year-old male presented with a 1-year history of polyarthralgia and contracture. He was referred to our hospital from a local doctor, who diagnosed him with rheumatoid arthritis (RA); however, treatment with methotrexate and etanercept was ineffective. The patient also reported a 15-kg weight loss over the past year, and subsequent evaluation revealed oesophageal cancer. Contrast-enhanced magnetic resonance imaging (MRI) demonstrated enhancement around the digital muscles, and we diagnosed him with palmar fasciitis and polyarthritis syndrome (PFPAS). A rare paraneoplastic syndrome, PFPAS is characterised by hand flexion contracture, thickening of the palmar fascia, and symmetric polyarthritis. To the best of our knowledge, this is the first reported case associated with oesophageal squamous carcinoma. On T1-weighted MRI, the finger tendons typically exhibit high signal intensity, whereas contrast-enhanced imaging highlights fascial enhancement. Skin biopsy usually reveals fibroblast proliferation and monocyte invasion; however, its mechanism is unclear. The efficacy of corticosteroids, nonsteroidal anti-inflammatory drugs, and disease-modifying antirheumatic drugs is limited, whereas cancer resection may improve arthritis, though contractures are often irreversible. PFPAS may be misdiagnosed as RA due to symmetric digital synovitis, which may let the cancer progress and progression of contracture may lead to low performance status Because PFPAS often precedes initial diagnosis, recurrence, and progression of cancer, prompt cancer evaluation is essential in patients presenting with RA-like symptoms, contracture, or unexplained weight loss.