A blue lesion on the foot

VMs can affect skin and underlying structures such as muscle and bone.

Clinical Scenario
Jane, a 34-year-old female, presents with a spongy lesion on the right medial foot (Figure 1a) that first appeared when she was a teenager.

The lesion is made up of a cluster of ill-defined soft tissue nodules, blue-green in colour and partially compressible. The lesion is slightly tender to palpation with no detectable pulsation or thrill.

She has several similar looking solitary spots (<1cm diameter) on her upper limbs and torso.

This lesion was diagnosed as a venous malformation 20 years ago when it first appeared. The patient has always been bothered by the appearance of the lesion, but is now more concerned about the pain when weight-bearing. She seeks management advice.

Venous malformation (VM)
Venous malformation (VM) is typically present at birth and grows in proportion to the rest of body. VMs can affect skin and underlying structures such as muscle and bone of the affected limb. Limb enlargement can occur with large VMs.

Lesions appearing later in life are typical of glomuvenous malformation (GVM), a variant of venous malformation. GVMs are commonly accompanied by widespread eruption of individual glomangiomas.

A bluish papule biopsied from Jane’s right arm revealed a glomangioma, which pointed to the diagnosis of a GVM of the foot, consistent with the history.

GVMs are raised blue-green vascular lesions that closely resemble classical VMs except GVMs are not present at birth but appear later in life. GVMs occurring on the foot can be painful with weight bearing and sudden increase in pain may correspond with episodic thrombosis.

GVMs can be confirmed on lesional biopsy where diagnostic glomus cells (immature smooth muscle cells) can be seen lining dilated venous channels. GVMs result from mutations in the glomulin gene and can be autosomal dominant. Treatment options for GVMs and VMs are essentially similar.

Classic VMs (without glomangiomas) can be diagnosed clinically, but ultrasound, magnetic resonance imaging (MRI) and computerised tomography (CT) scans can help delineate the extent of the malformation and any associated abnormalities. Duplex ultrasound is a quick, non-invasive method of investigating the malformation and can also be used to guide sclerotherapy of VMs.

Treatment
VMs respond well to ultrasound-guided sclerotherapy. Sclerosis (shrinkage) of the vascular channels occurs over a series of treatment sessions. External vascular lasers (1064nm Nd:YAG) may further shrink some of the smaller and more superficial lesions.

Surgery is an option for small isolated lesions but is not as useful for lesions with deeper involvement and for those close to vital neurovascular structures. In general, the outcome and prognosis of a VM is related to its location, size, type (diffuse versus circumscribed), and whether there is any involvement with vital neuromuscular structures.

A multidisciplinary team of dermatologist, paediatrician, radiologist, plastic surgeon and vascular surgeon may be required for complicated VM patients.

Case discussion
This patient had a soft-tissue and venous duplex ultrasound to confirm and map out the extent of the venous malformation. The malformation was treated with ultrasound-guided sclerotherapy with multiple injections of foam sclerosant (1.5% sodium tetradecyl sulphate). A vascular laser (1064nm Nd:YAG) was also used to further shrink the malformation externally.

A compression stocking was applied over the foot during the recovery to improve closure and sclerosis of the vascular malformation.

After a series of 3–4 treatment sessions, the malformation showed diminished soft tissue bulk and a more normal skin colour (Figure 1b). Over time, the malformation may slowly recur but can be effectively controlled with the above measures.


Figure 1b: After two sessions of sclerotherapy and one session of vascular laser therapy.

Key facts: Venous malformation

• Incidence: 1–4%
• Present at birth and grows in proportion with the child
• May be associated with soft tissue hypertrophy
• Can extend into muscles and bones
• Can be painful especially when thrombosed
• Coexisting psychological morbidity common
• Glomuvenous variants have a delayed onset (acquired)
• Glomuvenous variants show glomus cell proliferation on biopsy
• Duplex US, CT, MRI help define extent of lesion
• Sclerotherapy and surgical options can be effective.

Dr Adrian Lim
Fellow of the Australasian College of Dermatologists and of the Australasian College of Phlebology