Newborn Cardiac Hemangioma Single-Cell RNA Sequencing

This study focuses on a rare case of mixed-type intracardiac hemangioma in a 17-day-old female neonate, a benign vascular tumor with limited molecular characterization. We performed single-cell RNA sequencing (scRNA-seq) on the surgically resected right atrial tumor tissue (1.7x2.0x2.1 cm) to dissect the cellular and molecular mechanisms underlying cardiac hemangioma formation. After quality control, 4,888 high-quality cells were retained and classified into 9 distinct cell types, with fibroblasts/myofibroblasts and smooth muscle cells accounting for nearly half the population. Endothelial cells were subdivided into two functional clusters: one enriched in immune inflammation, cell adhesion, and signal transduction, and the other focused on mitochondrial energy metabolism and ribosome biogenesis. InferCNV analysis revealed relative genomic stability, supporting the tumor's benign nature. Cell communication analysis identified the inflammation-related endothelial cell cluster as the primary effector, receiving VEGF signals from myeloid-derived suppressor cells and common myeloid progenitors while driving collagen synthesis-related pathways. This work represents the first single-cell transcriptomic profiling of cardiac hemangioma, filling gaps in the molecular understanding of this rare neonatal tumor and providing potential therapeutic targets. The study also includes 1-year follow-up data confirming no recurrence and normal cardiac function in the patient.