Asian Journal of Case Reports in Surgery

Venous vascular malformations are rare congenital anomalies of the venous system that may remain clinically silent until childhood. We report a 6‑year‑old girl who presented with acute onset swelling and fever in the left axilla. Clinical examination revealed a soft, compressible mass that decreased in size on pressure. Initial ultrasonography demonstrated conglomerate lobulated suppurative lymphadenopathy with liquefied components, raising the possibility of an abscess. High‑resolution real‑time ultrasonography further showed a well‑defined multiloculated subcutaneous cystic mass with inter‑muscular extension and absent internal flow on colour Doppler, suggesting a lymphatic or venous malformation. MRI using T1, T2, STIR and post‑contrast sequences revealed a large hyperintense multiloculated lesion with fluid–fluid levels, internal septations and adjacent soft‑tissue involvement, without invasion of surrounding muscles or chest wall, features highly suggestive of a venous vascular malformation with haemorrhagic components. Based on the imaging findings, the patient was treated with multiple sessions of sclerotherapy using sodium tetradecyl sulfate under general anaesthesia. Progressive reduction in lesion size and resolution of symptoms were observed on follow‑up, with the child returning to normal activities. This case highlights the crucial role of multimodality imaging in accurate characterization of pediatric venous vascular malformations, guiding minimally invasive treatment, and preventing complications through early diagnosis and multidisciplinary management.