Venous lymphatic malformations (VLMs) represent a distinct category of vascular anomalies, characterized by their presence at birth, although they may become noticeable at any point in a person’s life. These non-cancerous growths involve abnormal development of both venous and lymphatic vessels.
What Are Venous Lymphatic Malformations
Venous lymphatic malformations originate from errors during fetal development. They are not true tumors that proliferate rapidly; instead, they are malformations that grow proportionally with the child or expand due to the accumulation of fluid within their abnormal channels. This distinguishes them from hemangiomas, which are proliferative vascular tumors that typically grow quickly in infancy before regressing.
VLMs are composed of two primary components: abnormally dilated venous channels and dysfunctional lymphatic channels. These intertwined vessels fail to connect properly with the normal circulatory and lymphatic systems. This structural defect leads to the pooling of blood and lymphatic fluid within the malformation, causing it to enlarge and exert pressure on surrounding tissues. The extent and specific composition of these abnormal vessels vary among individuals.
Identifying Symptoms
Symptoms of venous lymphatic malformations vary widely depending on their size, depth, and anatomical location. They often present as soft, compressible masses located just beneath the skin. Surface malformations may appear with a bluish or purplish discoloration.
These malformations can develop anywhere in the body, including the head, neck, limbs, trunk, or internal organs. Individuals may report pain, which can result from the expansion of the malformation, bleeding into the lesion, or compression of adjacent nerves. Chronic swelling, known as lymphedema, frequently accompanies VLMs due to the impaired drainage of lymphatic fluid.
VLMs can also lead to noticeable disfigurement, particularly when they occur in visible areas like the face or neck, causing asymmetry or prominent lumps. Recurrent infections, such as cellulitis or lymphangitis, are common, especially if the overlying skin is compromised or if stagnant fluid provides a breeding ground for bacteria. Bleeding, internal or external, can also occur. Depending on their location, VLMs can impair function, such as restricting limb movement, causing limb length discrepancies, or leading to difficulties with breathing or swallowing if located near the airway.
How They Are Diagnosed
Diagnosing venous lymphatic malformations begins with a thorough clinical examination and a detailed patient history. The medical professional assesses the lesion’s appearance, size, consistency, and compressibility, and gathers information about its onset, growth patterns, and associated symptoms. This helps differentiate VLMs from other growths.
Imaging studies confirm the diagnosis and map the full extent of the malformation. Magnetic Resonance Imaging (MRI) provides detailed visualization of the malformation’s components, its precise boundaries, and its relationship to surrounding muscles, nerves, and organs. MRI can also distinguish between the venous and lymphatic elements within the lesion.
Ultrasound is often used for initial assessment, providing real-time imaging that can help identify fluid-filled cysts and evaluate blood flow dynamics within the malformation. Computed Tomography (CT) scans may be used for bony involvement or for surgical planning requiring detailed skeletal anatomy, though they offer less soft tissue detail than MRI. A biopsy is not generally required for diagnosis unless the presentation is atypical or another underlying condition is suspected.
Treatment Options
The management of venous lymphatic malformations is individualized, considering the malformation’s size, location, symptoms, and the patient’s age. Treatment often involves a multidisciplinary team of specialists, including interventional radiologists, surgeons, and other specialists. The primary goal is to alleviate symptoms, reduce the malformation’s size, and improve function or cosmetic appearance.
Sclerotherapy is the most common and effective treatment for many VLMs. It involves injecting a sclerosant solution directly into the malformation’s abnormal channels. Commonly used agents include doxycycline, ethanol, bleomycin, or sodium tetradecyl sulfate, which induce an inflammatory reaction and scarring within the vessels, leading to their collapse and subsequent shrinkage. Multiple sessions of sclerotherapy are often needed to achieve desired results.
Surgical excision is an option for well-defined, localized lesions that are removable without causing significant functional impairment or disfigurement. However, complete removal can be challenging, especially for diffuse or deeply infiltrating lesions, and incomplete excision carries a risk of recurrence. Complications include nerve damage, bleeding, and scarring.
Laser treatment treats superficial VLMs, particularly those causing skin discoloration or involving small, visible vessels. It targets the vascular components to reduce their appearance and bulk. Medical management also plays a role in symptom control, involving pain medication, compression garments for swelling and support, and antibiotics for recurrent infections like cellulitis. In some complex or widespread cases, systemic medications such as sirolimus, an mTOR inhibitor, can reduce lesion size and symptoms by modulating abnormal cell growth and angiogenesis. For asymptomatic or stable lesions without functional or cosmetic concerns, a watchful waiting approach and monitoring may be appropriate.