Diagnostic Dilemma in Left Ventricular Noncompaction Cardiomyopathy: Thrombus or Tumor?

Left ventricular noncompaction cardiomyopathy (LVNC) is associated with thromboembolic complications and can complicate intracardiac mass interpretation. A 58-year-old man with prior left ventricular (LV) apical thrombus presented with abdominal pain and weight loss. Contrast-enhanced transthoracic echocardiogram (TTE) showed severe LV dysfunction (left ventricular ejection fraction (LVEF) 15-20%) and a 1.5 cm mobile apical mass with apparent central contrast uptake, raising concern for a tumor in the setting of suspected prostate malignancy. Heparin was initiated. On day 3, the mass had resolved, and repeat echocardiography demonstrated prominent apical trabeculations and a low-flow apex with findings suggestive of LVNC, indicating that the perceived "vascularity" likely reflected pseudo-enhancement. This case emphasizes serial imaging and multimodality assessment when uncertainty persists.