A 56-year-old woman presents with dry mouth and eyes for 2 years, polyarthralgia for 6 months (without joint swelling), CXR shows interstitial lung disease and mediastinal widening. ESR 30mm/h, RF 1:160, ANA 1:320. The most likely diagnosis is:
A 56-year-old woman presents with dry mouth and eyes for 2 years, polyarthralgia for 6 months (without joint swelling), CXR shows interstitial lung disease and mediastinal widening. ESR 30mm/h, RF 1:160, ANA 1:320. The most likely diagnosis is: