A 9-year-old female presented with mitral regurgitation, heart failure, fever, abnormal serum proteins, elevated sedimentation rate, and elevated antihyaluronidase titer. At first thought to have rheumatic fever, she initially responded favorably to medical therapy which included corticosteroids. Evidence of progressive disease led to cardiac catheterization and angiography which demonstrated a left atrial myxoma which was successfully excised.
Review of the literature reveals that 23 children with left atrial myxomas have been reported. These may present with embolic, obstructive, or constitutional symptoms. Most children have clinical evidence of mitral regurgitation. Associated heart failure, anemia, elevated sedimentation rate, elevated antihyaluronidase titer and initial favorable response to medical therapy often lead to the incorrect diagnosis of acute or chronic rheumatic heart disease.
In these patients, increased endogenous hyaluronic acid excretion from tumor cells may lead to increased hyaluronidase and antihyaluronidase activity, abnormal serum proteins and elevated sedimentation rate.