How I Do It: A Radiologist’s Checklist—Pitfalls and Take-home Message for Venous Malformations

Diagnosing venous malformations (VMs), the most common subtype of vascular anomalies, remains challenging due to their heterogeneous clinical and imaging presentations and frequent mimickers. Misclassification may lead to delayed or inappropriate management. This article presents the experience of a national reference center for vascular anomalies, proposing a structured clinico-radiological diagnostic workflow based on the integrated analysis of medical history (“When”), clinical examination (“How”), and imaging findings (“Which”). Key diagnostic “red flags” are highlighted, including late onset, rapid growth in adulthood, atypical coloration, persistent firmness, pulsatility, or discordant imaging features. Ultrasound plays a central role in confirming the vascular nature of lesions, assessing compressibility, flow characteristics, and dynamic behavior, while magnetic resonance imaging is used to define lesion extent and morphology and to exclude solid components. The presence of phleboliths is emphasized as a highly specific imaging feature of VM. A standardized checklist based on the International Society for the Study of Vascular Anomalies classification is proposed to ensure reproducible and comprehensive lesion description. Several illustrative cases underline common diagnostic pitfalls, including sarcomas, fibro-adipose vascular anomaly, myxomas, and other soft-tissue tumors misdiagnosed as VMs. The article underscores the importance of a multidisciplinary approach, systematic identification of red flags, and careful correlation of clinical and imaging findings to ensure accurate diagnosis and appropriate patient-tailored management.