Cardiac myxoma with glandular elements: a clinicopathological and immunohistochemical study of five new cases with an emphasis on differential diagnosis.

This paper reported five new cases of cardiac myxoma with glandular components, known as glandular cardiac myxoma. The goals of this study were to analyze the clinicopathological features of this disease and to explore new features for differential diagnosis. The patient series included three women and two men. All tumors were located in the left atrium without invasion of the adjacent myocardium. Patients presented with cardiac-related or embolization symptoms. Histologically, neoplasms consisted of well-formed glandular structures and typical myxoma areas. No nuclear atypia, mitosis, or necrosis was identified in the glandular structures. Glandular lining cells were strongly positive for pan-cytokeratin, epithelial membrane antigen, CAM5.2 and cytokeratin 7, but were negative for some organ-specific markers, such as thyroid transcription factor-1, calretinin, estrogen receptor, progesterone receptor, gross cystic disease fluid protein, prostate-specific antigen, prostate-specific acid phosphatase, cytokeratin 20 and caudal type homeobox 2. In conclusion, glandular cardiac myxoma is a rare disease which shows characteristics similar to those of classical cardiac myxoma. Because of its rarity, glandular cardiac myxoma must be distinguished from adenocarcinoma metastatic to the heart. The combination of histopathological features and immunohistochemical profiles should improve the diagnostic accuracy of glandular cardiac myxoma.