Today venous malformations (VMs) pose one of the most difficult challenges in the practice of medicine. Venous malformations are part of a spectrum of vascular malformations commonly found in adults. William Hunter was the first to describe vascular anomalies in the mid-18th century in the context of iatrogenic formation of arterio-venous fistulas by phlebotomists.1 Venous malformations (VMs) occur in vessels that have low blood flow and are morphologically, histologically similar to veins.2 Early attempts at classification were based on the pathology of the lesions without considering underlying biologic behavior. However, Glowacki and Mulliken recommended that vascular lesions be divided into two major groups - hemangiomas and vascular malformations - depending on histologic and clinical presentation.3 Years later, the Hamburg classification system adopted an embryologic perspective to further support the classification of vascular malformations.4 Which was later reclassified by Mulliken and Young and was adopted by the International Society for the Study of Vascular Anomalies (ISSVA) in 1996; and today it is the mainly used in classification with minimal changes to the original version.1
Arteriovenous malformation (AVM) is a congenital vascular malformation with a direct communication from arteries to veins with lack of normal capillary network. With its progression, AVM is capable of destroying normal tissues and can lead to complications, for instance severe disfigurement, unmanageable bleeding, ulceration, pain and cardiac volume overload.5 Initially lesions are recognized based on the prevailing vascular structure involved- arterial, venous, lymphatic, or capillary, considering arterio-venous shunting and also the combined vascular defects. The embryological background of the lesion is then considered for additional demarcation.6
A 30-year-old male patient reported with a complaint of pain in the lower right and left back tooth region since a week. Pain was insidious in onset, throbbing type, moderate in intensity, aggravated only while chewing food and relived after a while. He was moderately built and nourished with all the vital signs being normal. Extra oral examination revealed solitary swelling on the left cheek (Figure 1a) measuring about 5x6 cm, extending antero-posteriorly from body of mandible till 2mm in front of the ear, superio-inferiorly from the line joining angle of mouth and tragus up to the lower border of mandible. Then there were 2 – 3 small nodular swellings appreciated at the lateral border of the neck (Figure 1b), lined obliquely over the sternocleidomastoid muscle, each measuring about 2 to 3 cm. Surface of all the swellings appeared to be smooth with prominent nerves and vessels giving the swellings a bluish tint. On palpation, the swelling were painless and soft, with no rise in temperature. A nodule was confirmed within the swelling at the lower border of mandible and the ones over the neck, indicating palpable lymph nodes, which were mobile, firm and non-tender. Intra orally the tongue was disfigured at the tip and on the left side causing Macroglossia and difficulty in speech (Figure 2a). The tongue as well showed a bluish discoloration, being soft to firm in consistency, non-tender and showed increase in temperature. Hard tissue examination revealed root stumps with 38 and 48, which were tender on percussion. We arrived at a provisional diagnosis of apical periodontitis in relation to 38 and 48 as per the patient’s complaint. Based on the clinical appearance of the swellings of tongue, neck and cheek a provisional diagnosis of venous malformation was given, with a differential diagnosis of hemangioma and dermal melanocytic nevi.
We subjected the patient for OPG (orthopantomograph). His OPG (Figure 2b) revealed multiple calcifications. One calcification at the apical aspect of 36 overlying inferior alveolar canal and measuring 2x3 cm, roughly oval shaped. The other one at the lower border of the mandible corresponding to 36, 37, approximately of about 3x4 cm and is rounded. Four to five calcifications seen in the pharyngeal space, each measuring 1×1 cm. all the calcifications show various amount of radiolucency within them. The calcifications suggestive of phleboliths, was supporting our clinical diagnosis. Later on, patient was subjected to color-Doppler US (ultrasound) of the cheek. The images revealed lesion with heterogeneously hypoechoic with multiple anechoic sinusoidal spaces (longitudinal plane) with mild vascularization (Figure 3a) and spectral analysis shows monophasic venous flow (Figure 3b), defects in the venous flow confirms our diagnosis of venous malformation. Direct puncture venography of the left cheek (Figure 3c revealed pooling of contrast and draining into external jugular vein, showing opacification of venous malformation, which confirms our diagnosis. Patient was further referred to higher center for the appropriate treatment.
Vascular malformations are structural lesions resulting from errors of vascular morphogenesis. In other terms “Vascular malformation” is a generalized word used to portray a group of lesions, present at birth, formed by an anomaly of angiovascular or lymphovascular structures.7,8
In 1982, vascular anomalies (hemangioma) were grouped into two main major categories based on clinical, radiological and pathological features: “vascular tumors” and “vascular malformations’. This was first dichotomised in this way by Mulliken and Glowacki in 1982, based on the histology, natural history and cellular activity of these lesions (Table 1).9 This classification was later adopted in 1996 by the International Society for the Study of Vascular Anomalies (ISSVA) at the 1996 meeting in Rome, and then the classification system was expanded at the 2014 ISSVA workshop in Melbourne (Table 2).10 These lesions often have components of multiple malformations, such as a mixed lymphatico-venous malformation, further adding to the confusion with respect to proper nomenclature.11-24
Low-Flow Venous Malformations
Venous malformations are part of a spectrum of vascular malformations commonly found in adults.12 Venous malformation is defined as malformations comprised of slow-flowing, abnormal dilated veins, and venous network.13 Clinically, these lesions appear as a soft, compressible and blue mass, typically present within the cutaneous tissues of the face, trunk, and limbs, although involvement of the viscera and bones has also been described, as seen in the present case. It is noted that two thirds of all vascular malformations are venous predominant (Table 3).
Experienced clinician can arrive at the diagnosis based on clinical history (presence at birth, growth during life, triggers such as puberty or trauma, and family history) and examination (Table 3). Important clinical clues are color (variations of pink, red, blue and purple), aspect (flat, raised, homogeneous, patchy, hyperkeratotic and ulcerated), localization, size, distribution (uni- or multifocal), palpation (hard, firm, compressible, and presence of a thrill), temperature (warm or normal), painfulness (spontaneous or provoking factors) and auscultation (bruit).14
VMs are the most common type of vascular malformation, affecting 1% to 4% of individuals. The overall incidence of VM is about one in 10000.1 Although it is felt that there is no gender predisposition, one series did find a female preponderance.15 The oral cavity (59%) and nasal cavity (35%) were the most common locations. Tongue and lips are sites for the lesion involving oral cavity, and nasal septum in the nasal cavity.16,17
There was no evidence that drugs or medications taken during pregnancy, or environmental exposures that may have occurred during that time can cause venous malformations. 100% are present at birth, although not all are clinically apparent. Abnormal sprouting or branching during embryonic development can result in venous malformations.18
Patient’s history and physical examination normally provides sufficient information to make the diagnosis. Conventional radiography generally reveals a soft-tissue mass with an occasional phleboliths and seldom adjacent skeletal anomalies.12 Lesions that are in the head / neck region enlarge when the patient forces air from the lungs with the vocal cords held closed (Valsalva maneuver). They show a tendency to thrombosis, leading to phleboliths, which are pathognomonic of VM and are diagnostic on imaging studies. Phleboliths are intralesional calcifications formed as a result of venous stasis and inflammation.14
Ultrasound (US) is often the initial investigation to evaluate vascular malformations and it may characterize and define the extent of more superficial lesions.19
MRI is most useful for defining the extent of the disease. Angiography is also a useful modality for defining extent of disease, especially when identifying deep or small VMs, such as intracranial sinus pericranii or gastrointestinal VM.12-20
In the present case, phleboliths were seen on plain radiography and were suggestive of vascular anomaly with slow flow rate. Whereas, by direct phlebography the lesion was seen draining the regional vein. These investigation features were suggestive of venous malformation.
Low flow venous malformations could be treated by compression, surgical excision or sclerosis. Treatment should be reserved for symptomatic or cosmetically disfiguring malformations. Zheng et al. reported that laser therapy is recommended for superficial venous malformations17. A Sclerosing agent, which comprises the main type of treatment, includes STS (sodium tetradecyl sulfate), polidocanol, and absolute alcohol.21 Hyodoh H et al reported excellent results with sclerotherapy in 53%-100% patients.22 According to Lee BB et al, success rates using absolute alcohol have been reported in up to 95% with no evidence of recurrence.23, 24
In comparison to hemangiomas, vascular malformations diagnosed at birth shows no signs of involution with age and might expand close to puberty. In our case swelling was seen later in life, which was bluish in color and no signs of palpation or rise in temperature, leads to the diagnosis of venous malformation. Further the investigations show positive results, the OPG shows phleboliths, which is again a pathognomonic of the lesion. The ultra sound with monophasic venous flow (Figure 3b), defects in the venous flow and direct venography confirms our diagnosis of venous malformation.