<?xml version='1.0' encoding='UTF-8'?><xml><records><record><source-app name="HighWire" version="7.x">Drupal-HighWire</source-app><ref-type name="Journal Article">17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">KIM, HONG-BEUM</style></author><author><style face="normal" font="default" size="100%">LEE, YEON-AH</style></author><author><style face="normal" font="default" size="100%">KIM, SEONG-HUN</style></author><author><style face="normal" font="default" size="100%">PARK, SANG-GON</style></author></authors><secondary-authors></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Capillary Hemangioma of the Breast Parenchyma Mimicking New Primary Cancer or Metastasis During Ramucirumab Therapy for Advanced Gastric Cancer</style></title><secondary-title><style face="normal" font="default" size="100%">In Vivo</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2026</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2026-01-01 00:00:00</style></date></pub-dates></dates><pages><style  face="normal" font="default" size="100%">545-550</style></pages><doi><style  face="normal" font="default" size="100%">10.21873/invivo.14219</style></doi><volume><style face="normal" font="default" size="100%">40</style></volume><issue><style face="normal" font="default" size="100%">1</style></issue><abstract><style  face="normal" font="default" size="100%">Background/Aim: Ramucirumab, a monoclonal antibody targeting vascular endothelial growth factor receptor-2 (VEGFR-2), has been shown to prolong survival in patients with advanced gastric cancer when combined with paclitaxel as second-line chemotherapy in the RAINBOW study. The most common adverse events include hypertension, proteinuria, and hemorrhage, reflecting its anti-angiogenic activity. Although the VEGF signaling pathway is strongly implicated in the pathogenesis of hemangiomas, the development of new hemangiomas during VEGFR-2 inhibition is rarely reported.Case Report: A 38-year-old woman with stage IV gastric adenocarcinoma presented with peritoneal dissemination and lymph node metastasis. She initially received FOLFOX plus immune checkpoint inhibitor therapy, achieving a partial response before disease progression. Second-line treatment with paclitaxel and ramucirumab was initiated. During therapy, chest computed tomography revealed a newly developed contrast-enhancing nodule in the left breast parenchyma, raising suspicion of metastasis or primary breast carcinoma. Breast ultrasonography confirmed a hypervascular lesion, and ultrasound-guided biopsy demonstrated numerous capillary-sized vessels lined by bland endothelial cells, consistent with capillary hemangioma. Owing to deterioration of her general condition, chemotherapy was temporarily discontinued. Despite subsequent third-line FOLFIRI and fourth-line trifluridine/tipiracil treatment, the patient eventually died of disease progression. Notably, follow-up chest CT scans showed gradual reduction and eventual spontaneous disappearance of the breast hemangioma, independent of systemic therapy.Conclusion: This is a rare case of a breast parenchymal capillary hemangioma arising during ramucirumab therapy for advanced gastric cancer, which regressed spontaneously. Clinicians should recognize that atypical vascular lesions may develop paradoxically during VEGFR-2 blockade and confirm histological diagnosis to avoid misinterpretation as metastasis or new primary malignancy.</style></abstract></record></records></xml>