A Pseudotumoral Lesion of the Mitral Annulus: Diagnostic Approach and Clinical Implications

Abstract

Background: Caseous calcification of the mitral annulus (CCMA) is a rare variant of mitral annular calcification characterized by liquefaction necrosis within chronically calcified annular tissue. Its pseudotumoral appearance may mimic cardiac tumors or infective processes, creating significant diagnostic challenges. Case Presentation: An 81-year-old female patient was referred for preoperative cardiac assessment in advance of elective hip arthroplasty. She was asymptomatic and classified as New York Heart Association (NYHA) functional class I. Transthoracic echocardiography demonstrated a well-circumscribed mass measuring 23 × 20 mm situated at the posterior mitral annulus, accompanied by mild mitral stenosis, with a mitral valve area of 1.9 cm² and a mean transvalvular gradient of 5 mmHg. Left ventricular systolic function was preserved. Cardiac magnetic resonance imaging demonstrated a hypointense lesion with peripheral late gadolinium enhancement, while computed tomography confirmed a hypodense mass with peripheral calcifications, consistent with caseous degeneration. Laboratory findings were unremarkable. A conservative approach was adopted. The patient underwent orthopaedic surgery without complications, and six-month follow-up echocardiography showed stable findings. Conclusion: CCMA should be included in the differential diagnosis of mitral annular masses in elderly individuals. The use of multimodality imaging is integral to accurate diagnosis and is essential in avoiding unwarranted surgical intervention.