婴儿猝死仍然是美国儿童死亡的一个常见且鲜为人知的原因。小儿心脏肿瘤虽然罕见，但可能是一些无法解释的婴儿猝死病例的原因。在这些病例中，尸检是至关重要的诊断步骤，因为心脏的肉眼和显微镜检查都可能发现隐匿性心脏肿瘤。横纹肌瘤是儿童最常见的心脏肿瘤，可能导致心律失常和猝死。我们报告了一名健康 5 个月大婴儿猝死的病例，该婴儿最初表现出“SIDS 样”，直到彻底的组织学分析显示潜在的心脏横纹肌瘤。该病例特别重要，因为心脏的大体检查被认为完全正常，并且显微镜下肿瘤仅累及心脏的某些部分。如果心肌的单个随机切片是唯一用显微镜检查的心脏切片，则可能会漏掉诊断。该病例强调了对婴儿病例进行彻底显微镜检查的重要性，特别是在心脏看起来非常正常的情况下。© 2024。作者。

Sudden death in infants remains a common and poorly understood cause of childhood mortality in the USA. Pediatric cardiac tumors, although rare, may underlie some cases of unexplained sudden infant death. Autopsy is a crucial diagnostic step in these cases, as both gross and microscopic examination of the heart may uncover occult cardiac tumors. Rhabdomyomas are the most common cardiac tumors in childhood and may result in arrythmia and sudden death. We present a case of sudden death in a healthy 5-month-old infant which initially appeared "SIDS-like" until thorough histological analysis revealed an underlying cardiac rhabdomyoma. The case is of particular importance in that the gross examination of the heart was considered completely normal, and the tumor only involved certain portions of the heart microscopically. Had a single random section of myocardium been the only heart section examined microscopically, the diagnosis might have been missed. This case emphasizes the importance of thorough microscopic examination in infant cases, especially in cases where the heart appears grossly normal.© 2024. The Author(s).