Venous lake

A venous lake is an asymptomatic, generally solitary, soft, compressible, dark blue to violaceous, 0.2- to 1-cm papule commonly found on sun-exposed surfaces of the vermilion border of the lip, face and ears. Lesions generally occur among the elderly.

Though these lesions may resemble nodular melanoma, the lack of induration, slow growth, and lightening appearance upon diascopy suggest against it, and indicate a vascular lesion. Additionally, lack of pulsation distinguishes this lesion of the lower lip from a tortuous segment of the inferior labial artery.

Cause
The cause is unknown; however it is thought to be associated with sun exposure, leading to a dilated blood-filled vascular channel "...lined with a singled layer of flattened endothelial cells and a thin wall of fibrous tissue filled with red blood cells."

Treatment
Treatment is not necessary, and patients should be reassured of the lesion's non-malignant nature. However, if treatment is sought for cosmetic reasons, lesions can be treated with surgical excision, laser therapy, infrared coagulation, cryotherapy, and sclerotherapy.