Laskar Arifa B, Dey Biswajit
Pathology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, IND.
Cureus. 2025 Aug 23;17(8):e90788. doi: 10.7759/cureus.90788. eCollection 2025 Aug.
Mesothelial/monocytic incidental cardiac excrescences (MICE) are rare, reactive tumor-like lesions of the heart. They are typically incidental findings during cardiac surgery. They can mimic thrombi or neoplasms such as myxoma, papillary fibroelastoma, and metastatic carcinoma histopathologically, leading to diagnostic confusion. We report a case of atrial MICE in a 40-year-old woman with rheumatic mitral stenosis and long-standing atrial fibrillation, who underwent mitral valve replacement following a failed percutaneous transvenous mitral commissurotomy. Histopathological examination revealed characteristic features of MICE in the left atrial appendage, with clusters of mesothelial cells and histiocytes embedded in fibrin, confirmed by immunohistochemistry. This case underscores the need for heightened awareness among pathologists to avoid misdiagnosis.
间皮/单核细胞性心脏偶发赘生物（MICE）是罕见的、心脏的反应性肿瘤样病变。它们通常是心脏手术中的偶然发现。在组织病理学上，它们可类似于血栓或肿瘤，如黏液瘤、乳头状纤维弹性瘤和转移癌，从而导致诊断混淆。我们报告一例40岁患有风湿性二尖瓣狭窄和长期心房颤动的女性患者的心房MICE病例，该患者在经皮经静脉二尖瓣交界切开术失败后接受了二尖瓣置换术。组织病理学检查显示左心耳有MICE的特征性表现，有成团的间皮细胞和组织细胞嵌入纤维蛋白中，免疫组织化学证实了这一点。该病例强调病理学家需要提高认识以避免误诊。
