Unrecognized partial anomalous venous return

This 38 y.o. woman had been under treatment for several years for pulmonary hypertension, on the presumption that it was idiopathic. Only when hopsitalized and a venous catheter line was placed from the left that the tip slipped into the right upper pulmonary vasculature was it realized that she had partial pulmonary venous return. 

When a venous access line was placed from the left, the catheter tip slipped into upper pulmonary vasculature (arrow), indicating presence of partial anomalous pulmonary venous return of right upper veins into the superior vena cava.