Intralesional Bleomycin in the Management of Low-flow Vascular Malformations - A Case Report

Abstract

Rationale:

Low-flow vascular malformations (LFVMs) of the orofacial region are rare congenital vascular anomalies caused by aberrant development of venous and lymphatic channels, leading to slow or stagnant blood flow. This report highlights the successful management of LFVMs of buccal mucosa using ultrasound-guided bleomycin sclerotherapy.

Patient Concerns:

A 37-year-old female presented with a 5-year history of progressive, painless swelling of the left buccal mucosa.

Diagnosis:

Clinical and radiological evaluation, including computed tomography (CT) angiography, confirmed a LFVM supplied by the left facial artery with venous drainage into the retromandibular vein.

Treatment:

The patient underwent three weekly sessions of ultrasound-guided intralesional bleomycin sclerotherapy (15 IU in 10 mL sterile water).

Outcomes:

One-year follow-up CT angiography showed minimal residual tissue with no recurrence and a 70% reduction in lesion size was noted.

Take-away Lessons:

Ultrasound-guided bleomycin sclerotherapy is a safe, minimally invasive and effective treatment for LFVM in cosmetically sensitive facial regions.

INTRODUCTION

Low-flow vascular malformations (LFVMs) are congenital vascular anomalies resulting from abnormal vascular development during embryogenesis.[1,2,3] They are usually present at birth but may remain unnoticed until trauma, infection or hormonal changes cause progressive enlargement. Unlike haemangiomas, LFVMs lack endothelial proliferation and do not regress spontaneously. Nearly half occur in the head and neck, where management is complicated by dense vascularity and cosmetic concerns.[3,4,5] These lesions are characterised by the absence of arterial shunting and include venous, lymphatic, capillary or mixed types. Traditional surgery and embolisation show high recurrence, whereas ultrasound-guided intralesional bleomycin sclerotherapy provides a safe, effective and durable alternative.

CASE REPORT

A 37-year-old female presented with a persistent swelling over the left buccal cheek that had progressively enlarged over five years. The swelling was painless, with no bleeding causing significant aesthetic concern. She had previously undergone extraction of the maxillary left first molar (tooth 26) by a private practitioner, suspecting an odontogenic cause. Clinical examination revealed an edentulous space between the upper left second premolar and second molar, confirming the extraction history. Despite the dental intervention, the swelling persisted, prompting further evaluation.

On clinical examination, a diffuse swelling measuring approximately 5 cm × 5 cm was noted on the left side of the face, extending superiorly from the zygomatic arch to about 3 cm above the inferior border of the mandible and anteroposteriorly from approximately 2 cm lateral to the ala of the nose to about 5 cm anterior to the tragus, corresponding to the region between the ala-tragal and cantho-tragal reference lines [Figure 1a]. The overlying skin appeared normal in colour and texture, with no evidence of discolouration, sinus formation, scars or visible pulsations. On palpation, the swelling was soft to firm in consistency, fluctuant, compressible, mobile and non-tender, with normal surface temperature and no palpable thrill or audible bruit. Intraorally, the swelling was measuring approximately 4 cm × 3 cm in the left buccal vestibule, extending anteroposteriorly from the region of upper left first premolar to third molar [Figure 1b]. The overlying mucosa was normal in colour and texture, without ulceration, discolouration or visible pulsations. On palpation, the intraoral swelling was soft to firm in consistency, fluctuant, compressible, mobile and non-tender, with no rise in local temperature and no palpable thrill or pulsation.

Figure 1.

Pre-operative clinical photographs showing (a) diffuse swelling over the left buccal region and (b) intraoral view showing buccal vestibular swelling in the premolar–molar region

As part of the initial evaluation, an ultrasound of the cheek and neck region was performed which elicited muscular hypertrophy and no other significant abnormalities. This was followed by Doppler ultrasonography of the carotid and vertebral arteries to exclude high-flow vascular malformations or major arterial involvement that could alter treatment planning. This Doppler study was reported normal. Following this a contrast-enhanced magnetic resonance imaging (MRI) revealed a vascular lesion within the left buccal space suggestive of a LFVMs. Computed tomography (CT) angiography was performed to evaluate the flow characteristics and revealed a well-defined, lobulated lesion measuring 32 × 31 × 27 mm in the left buccal space, closely abutting the buccinator muscle and the undersurface of the zygomaticus muscle [Figure 2a and b]. The lesion showed progressive centrifugal enhancement, with arterial supply from the left facial artery and venous drainage into the retromandibular vein, confirming the diagnosis of a LFVM [Figure 3a–c].

Figure 2.

Contrast-enhanced computed tomography showing a well-defined hyperdense vascular lesion in the left buccal space: (a) coronal view, (b) axial view, consistent with a low-flow arteriovenous malformation

Figure 3.

Computed tomography angiography showing (a) a lobulated lesion in the left buccal region supplied by a branch of the left facial artery, indicated by the arrow; (b) three-dimensional reconstruction of the lesion, indicated by the arrow; and (c) venous drainage into the retromandibular vein, indicated by the arrow

After review, a diagnosis of LFVM was established and ultrasound-guided intralesional sclerotherapy with bleomycin was chosen as the preferred treatment. Informed written consent was obtained after detailed counselling regarding risks, benefits and expected outcomes.

Treatment was performed under local anaesthesia. The dosage was calculated at 0.5 mg/kg, not exceeding 15 mg per session.[6] A total of 15 IU of bleomycin diluted in 10 mL sterile water was injected directly into the lesion under ultrasound guidance to ensure accurate intralesional delivery and avoid intravascular injection. The procedure was repeated weekly for three consecutive sessions. The patient tolerated all sessions well, with no complications such as ulceration, infection or scarring.

At 6 months, the patient reported approximately 70% reduction in swelling with marked improvement in facial symmetry and appearance [Figure 4]. At a 1-year follow-up, CT angiography was repeated and demonstrated a residual non-enhancing soft-tissue lesion measuring 16 mm × 13 mm in the subcutaneous plane deep to the zygomaticus minor muscle, without identifiable feeding or draining vessels [Figure 5a and b]. The patient remained asymptomatic and satisfied with the aesthetic and functional outcome.

Figure 4.

Post-treatment clinical photograph after 1 year showing improved facial symmetry

Figure 5.

One-year follow-up computed tomography angiography showing (a) resolution of the vascular lesion with no abnormal vascular enhancement, and (b) small residual non-enhancing soft-tissue lesion in the left buccal space without identifiable feeding vessels

DISCUSSION

LFVMs are the congenital anomalies of structurally abnormal venous, lymphatic or mixed vessels lacking arterial components and exhibiting sluggish haemodynamics.[1,2,3,4,5] They occur most frequently in the head and neck, where complex anatomy and cosmetic considerations make diagnosis and treatment challenging.[2,5] Their presentation is variable and may mimic odontogenic or soft-tissue pathologies, often leading to misdiagnosis. In this case, the lesion was initially mistaken for an odontogenic swelling, and a tooth was extracted without resolution – highlighting the importance of thorough imaging before intervention.

Imaging is crucial for the diagnosis, determining flow characteristics and planning management. Doppler ultrasound offers preliminary assessment of vascular flow, while MRI delineates soft-tissue extent and lesion margins. CT angiography provides detailed visualisation of feeding arteries, draining veins, flow characteristics and vascular architecture which are the key parameters in planning interventional procedures.[3,4] In the head and neck, LFVMs often involve branches of the external carotid artery, particularly the facial, internal maxillary or superficial temporal arteries with venous drainage via the facial or retromandibular veins.[3,4] In this case, CT angiography confirmed a lesion supplied by the facial artery and drained by the retromandibular vein, guiding the decision for sclerotherapy.

Several treatment modalities are suggested for LFVMs. Vessel ligation is largely obsolete, as collateral circulation leads to recurrence. Embolisation can reduce vascularity and assist surgical planning but rarely achieves cure alone and carries risks such as distal ischaemia and embolic migration.[3,4] Surgical excision, although potentially definitive, is often limited by diffuse lesion margins and high morbidity, especially in aesthetic facial zones.[4,5]

Sclerotherapy has emerged as the treatment of choice for most LFVMs. Ethanol, although potent, causes complications such as necrosis, neuropathy and systemic toxicity.[4,5] Safer agents such as sodium tetradecyl sulfate and polidocanol have improved safety profiles but often require multiple sessions with variable results in extensive lesions.[5]

Bleomycin has gained prominence for its selective endothelial cytotoxicity. It induces DNA strand breaks in vascular endothelial cells, leading to fibrosis and obliteration of abnormal channels while preserving surrounding tissue. Compared with ethanol, it carries minimal risk of necrosis, neuropathy, or systemic toxicity when administered within recommended limits. In addition, bleomycin causes less post-procedural pain, oedema and scarring, making it particularly suitable for lesions in the face and neck.[5] The recommended maximum dose per session (15 IU) corresponds to approximately 0.5 mg/kg, maintaining systemic levels below those associated with pulmonary toxicity.[6,7,8,9]

This case emphasises several key aspects: accurate imaging is indispensable for diagnosis and treatment planning; a multidisciplinary approach ensures optimal management and bleomycin sclerotherapy offers a minimally invasive, cosmetically favourable and functionally effective alternative to surgery.

CONCLUSION

LFVMs of the orofacial region are rare congenital anomalies that can clinically resemble odontogenic or soft-tissue lesions. Accurate diagnosis through appropriate clinical examination and imaging is essential for guiding treatment. Ultrasound-guided intralesional bleomycin sclerotherapy represents a safe, minimally invasive and effective modality that achieves significant lesion regression with excellent aesthetic and functional outcomes, minimal morbidity and low recurrence.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.