Abdelhammed Mokhtar H, Ramani Nisha S
Department of Pathology and Immunology, Baylor College of Medicine, Houston, USA.
Cureus. 2025 Apr 4;17(4):e81734. doi: 10.7759/cureus.81734. eCollection 2025 Apr.
Adenomatoid tumors (ATs) are rare benign neoplasms of mesothelial origin, commonly found in the genital tracts but occasionally reported in extragenital locations, including the thoracic cavity. We describe the second case of a pericardial AT in a 65-year-old male with multiple comorbidities, including end-stage renal disease, diabetes mellitus, and heart failure. A small pericardial nodule was incidentally discovered during coronary artery bypass graft surgery without any clinical evidence of pericardial thickening. Histopathologic evaluation showed a well-circumscribed nodule with solid nests of epithelioid to spindled cells with bland cytology within a fibrous stroma. Immunohistochemical analysis demonstrated strong and diffuse positivity for calretinin, D2-40, WT-1, and pan-cytokeratin, confirming mesothelial differentiation. Markers of epithelial origin like MOC-31 and BerEp4 were negative, excluding the possibility of carcinomas of unknown origin. BAP1 nuclear expression was retained, and fluorescence in situ hybridization (FISH) for p16 () was negative for homozygous deletion, distinguishing the lesion from mesothelioma. Besides contributing to the limited body of knowledge on extragenital and thoracic ATs, this case adds to the limited number of reports on pericardial ATs, providing an understanding of the rare occurrence of these tumors arising from the pericardium.
腺瘤样瘤（ATs）是一种罕见的间皮源性良性肿瘤，常见于生殖道，但偶尔也有报道发生于包括胸腔在内的生殖器外部位。我们描述了第二例发生在一名65岁男性的心包AT病例，该患者有多种合并症，包括终末期肾病、糖尿病和心力衰竭。在冠状动脉搭桥手术中偶然发现一个小的心包结节，当时没有心包增厚的任何临床证据。组织病理学评估显示一个边界清楚的结节，在纤维性间质内有实性巢状的上皮样至梭形细胞，细胞形态温和。免疫组化分析显示钙视网膜蛋白、D2-40、WT-1和泛细胞角蛋白呈强阳性且弥漫分布，证实为间皮分化。上皮起源标志物如MOC-31和BerEp4为阴性，排除了不明来源癌的可能性。BAP1核表达保留，p16（）的荧光原位杂交（FISH）检测纯合缺失为阴性，将该病变与间皮瘤区分开来。除了丰富关于生殖器外和胸腔ATs的有限知识外，该病例还增加了心包ATs的有限报道数量，有助于了解这些起源于心包的肿瘤的罕见发生情况。
