Diagnostic challenges of recurrent left atrial mass: a case report.

Myxoma is the second most frequent benign primary cardiac tumour. Left atrial thrombi can occasionally mimic the typical echocardiographic appearance of a myxoma, and pathological features can sometimes overlap generating diagnostic confusion. Calretinin fixation is useful for differential diagnosis once it is only identified in myxomas but not in thrombi. Any discrepancy between clinical findings and histology should always mandate a review of histological preparations.