Vascular malformations consist of a spectrum of lesions involving all parts of the body. They have different terminologies like vascular tumors, vascular malformations, vascular anomalies, and so on, which create a lot of confusion in understanding and treating these pathologies. Of late, classification on the basis of cellular kinetics and clinical behavior has been devised. Hemangioma is the most common vascular tumor. Vascular malformations are of either lymphatic or capillary and venous origin. Sometimes they are of a mixed origin. Lymphangiomas are common in the face and neck area. They are also not unusual in the mediastinum. We present a case where a huge lymphangioma occupied the right supraclavicular area of the neck, extending to nearly the entire right thoracic cavity, compressing the whole lung. The patient had occasional symptoms of cough. Ultrasonography (US) and computed tomography (CT) images clearly described the lesion as cystic, occupying both the supraclavicular and thoracic cavity compressing the lung parenchyma. Surgical excision was planned and we approached the lesion via both cervical and thoracotomy incisions. Complete excision was done, and the lung expended fully after the surgery.