A venous lake is an asymptomatic

Asymptomatic

In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...

, generally solitary, soft, compressible, dark blue to violaceous, 0.2- to 1-cm papule

Papule

A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm.With regard to the quote "...varying in size from a pinhead to 1cm," depending on which text is referenced, some authors state the cutoff between a papule and a plaque as 0.5cm,...

 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

Nodular melanoma

Nodular melanoma is the most aggressive form of melanoma. It tends to grow more rapidly in thickness than in diameter. Instead of arising from a pre-existing mole, it may appear in a spot where a lesion did not previously exist...

, the lack of induration, slow growth, and lightening appearance upon diascopy

Diascopy

Diascopy is a test for blanchability performed by applying pressure with a finger or glass slide and observing color changes.It is used to determine whether a lesion is vascular or nonvascular or hemorrhagic . Hemorrhagic lesions and nonvascular lesions do not blanch; inflammatory lesions do...

 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

Inferior labial artery

The Iinferior labial artery arises near the angle of the mouth; it passes upward and forward beneath the Triangularis and, penetrating the Orbicularis oris, runs in a tortuous course along the edge of the lower lip between this muscle and the mucous membrane.It supplies the labial glands, the...

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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

Malignant

Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...

 nature. However, if treatment is sought for cosmetic reasons, lesions can be treated with surgical excision, electrocoagulation, laser therapy, infrared coagulation, cryotherapy

Cryotherapy

Cryotherapy is the local or general use of low temperatures in medical therapy or the removal of heat from a body part. The term "cryotherapy" comes from the Greek cryo meaning cold and the word therapy meaning cure...

, and sclerotherapy

Sclerotherapy

Sclerotherapy is a procedure used to treat blood vessels or blood vessel malformations and also those of the lymphatic system. A medicine is injected into the vessels, which makes them shrink. It is used for children and young adults with vascular or lymphatic malformations...

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