Venous malformation phleboliths mimicking submandibular sialadenitis in children

Abstract

To report one paediatric patient who presented with a rare venous vascular malformation as a mass in the left submandibular region with a clinical picture compatible with sialadenitis. Phleboliths are a specific feature of venous malformations due to venous stasis and may mimic sialoliths on various imaging modalities. Thus venous malformations are often misdiagnosed as sialadenitis due to sialolithiasis. Sialoliths are extremely rare in paediatric patients. In an early adolescent presenting with a submandibular mass and suspected sialadenitis arising from sialoliths, a detailed history, clinical examination and careful review of the radiological findings will allow the diagnosis of venous vascular malformation and provide the complete surgical resection. Our patient was initially referred with a presumed diagnosis of submandibular sialadenitis, and instead a venous malformation with phlebolith was diagnosed.

Background

Sialadenitis is estimated to have an annual incidence of 1 per 30 000. The most common cause is sialolithiasis of the submandibular gland.¹ The symptoms of sialadenitis are unilateral, episodic postprandial swelling and pain around the affected salivary gland. Sialadenitis arising from sialolithiasis, however, is uncommon in children. Virus infections are the main cause of sialadenitis in paediatric population.

Venous malformation phleboliths located in the submandibular region can present with the same symptomatology as sialadenitis due to sialoliths.

Vascular malformations are relatively common soft tissue tumours of the face and neck region. Vascular malformations are subcategorised on the basis of their histological features as lymphatic, capillary, venous, arteriovenous and mixed malformations and according to haemodynamical features as slow flow (either capillary, venous, lymphatic or combined forms) or ‘fast flow’ (arteriovenous fistulas and arteriovenous malformation).² Venous malformations are considered low-flow lesions.

Imaging with non-contrast-enhanced CT scan can reveal multiple calcified density areas characteristic of either phleboliths or sialoliths.

Case presentation

An otherwise healthy female early adolescent presented at the ENT department for investigation and treatment of suspected sialadenitis of the left submandibular gland. The patient developed since 3 months recurrent episodes (three episodes) of swelling in the left submandibular region, which fluctuated in size depending on swallowing movements. She exhibited none of the symptoms of submandibular duct obstruction due to sialolithiasis, particularly no increase in submandibular gland size, pain or postprandial discomfort. Vital signs were found to be normal during a general examination. ENT clinical examination revealed a large, solitary, non-pulsatile palpable mass on the submandibular triangle. On palpation, the above mass was ovoid in shape, movable and not fixed to the superficial skin with no warmth or tenderness. There were no palpable cervical lymph nodes. Saliva was flowing freely from the ipsilateral duct of Wharton, and there were no palpable sialoliths.

Investigations

Further investigations were performed.

A neck ultrasound detected a multilocular cystic tumour of 3.5×2.8 cm accompanied by low-level internal echoes in the left submandibular region. The lesion is related to the carotid space posteriorly, the sternocleidomastoid muscle laterally and the submandibular gland medially.

A contrast-enhanced MRI was followed. A homogeneously enhancing mass distinct from the left submandibular gland with hyperintense signal on T2 sequence, with multiple well-defined hypodense areas compatible with phlebitis within a venous vascular malformation, was revealed.

Differential diagnosis

Initial clinical diagnoses in our cases included sialadenitis, cyst or submandibular gland neoplasm.

Inflammatory diseases of the gland or lymph node; neoplasms such as pleomorphic adenoma, lymphangioma, lipoma and intramuscular haemangioma; and cystic masses like branchial cleft cysts or malignancies are typically included in the differential diagnosis of submandibular triangle masses. The history, physical examination and imaging techniques all show that these disorders can be distinguished from one another.³

Sialadenitis is also a common cause of submandibular gland swelling. Submandibular sialadenitis is an inflammation of the submandibular gland, caused by salivary stasis due to sialoliths. Sialadenosis is a benign, non-inflammatory swelling of the salivary glands commonly associated with metabolic conditions. Submandibular sialadenitis and sialadenosis have specific pathophysiological, histopathological and clinical features.

Treatment

After a discussion with the parents, a decision was made in favour of surgical excision.

The lesion was well defined, non-infiltrative and contained to a single fascial plane; therefore, surgical removal was planned.

Under general anaesthesia with orotracheal intubation, a horizontal submandibular incision placed two finger breadths below the left angle of mandible extending from midline to the anterior border of sternocleidomastoid muscle (figure 1). Then flap elevated along subplatysmal plane and fascia covering the left submandibular gland was dissected and elevated (figure 2).

Figure 1.

A horizontal submandibular incision placed two finger breadths below the left angle of mandible extending from midline to the anterior border of sternocleidomastoid muscle.

Figure 2.

Flap elevated along subplatysmal plane and fascia covering the left submandibular gland was dissected and elevated.

A reddish-blue mass was observed deep to the superficial fascia and the platysma above and attached to the underlying submandibular gland (figure 3).

Figure 3.

A reddish-blue mass was observed deep to the superficial fascia and the platysma above and attached to the underlying left submandibular gland.

The tumour was delineated from the surrounding structures. Then it was removed en bloc with ligation of the facial vein, which was the feeding vessel, and sent for histopathological evaluation (figure 4).

Figure 4.

The tumour was delineated from the surrounding structures and removed en bloc with ligation of the facial vein.

The marginal mandibular nerve was identified and preserved. Tendon of digastric, mylohyoid muscle and hypoglossal nerve were also identified and preserved.

Histopathological examination of the mass revealed lobules of blood-stained cavernous spaces covered by flattened endothelium. Interstitial fibrous tissue was seen interspersed with chronic inflammatory cells. This supported the diagnosis of venous vascular malformation.

Outcome and follow-up

One-year follow-up revealed no evidence of recurrence. The patient is still on follow-up and remains asymptomatic.

Discussion

Vascular malformations are congenital lesions of abnormal vascular growth with global incidence of 1 in 10 000.⁴ Venous malformations were formerly classified as cavernous haemangioma. Patient may present with non-specific symptoms including pain and swelling, which may be associated with phleboliths or venous stasis. Eivazi et al demonstrated with image techniques that calcium carbonate-fluorohydroxylapatite is the major component and the larger phleboliths have higher cortical density and higher contrast compared with smaller ones.⁵

Venous malformation management options depend on the type, the location and the extension of the lesion. For smaller asymptomatic venous malformations, observation of sclerotherapy with bleomycin, sodium tetradecyl sulfate and ethanol is indicated. Surgical treatment is preferred in cases of larger malformations, sudden and rapid tumour growth, severe functional impairment, local skin necrosis, thrombocytopenia and cosmetic disfigurement. Local recurrence may occur due to inadequate surgical resection, diffuse malformations or involvement of adjacent structures.

Three adult patients reported with venous malformation were initially diagnosed as submandibular salivary gland sialolithiasis.^6–8

Sialolithiasis is a very uncommon cause of sialadenitis in children. Three paediatric patients have been reported in the literature with venous vascular malformations.^{9 10}

The first case was a paediatric patient with a 6-month history of a mass in the left submandibular area mimicking dermoid cyst from clinical and diagnostic features. The diagnostic procedure included aspiration with needle and CT. Under general anaesthesia, an intraoral incision was made in the floor of the mouth.⁹ Although there was no noticeable bleeding, the appearance and character were compatible with a vascular tumour. After the histopathological examination, the lesion was diagnosed as an arteriovenous malformation in the floor of the mouth. In a follow-up for 2 years, the patient showed no evidence of recurrence.

The second paediatric patient, a female, was referred to the otorhinolaryngologists for treatment of suspected sialolithiasis of the submandibular gland. She exhibited none of the symptoms of submandibular duct obstruction due to sialolithiasis, particularly no increase in submandibular gland size, pain or postprandial discomfort.

The workup included an ultrasound, CT scan, cytology from fine-needle aspiration and MRI with gadolinium. Right submandibular gland sialolithiasis was diagnosed.

CT scan revealed a soft tissue mass that was distinct from the submandibular gland and had several sites of calcification.

Contrast-enhanced MRI showed a homogenously enhancing lobulated tumour, separate from the right submandibular gland, with numerous distinct hypodense regions, which was consistent with vascular malformation containing phleboliths.

Because the only sign was a mild, asymptomatic right submandibular enlargement, observation was advised.¹⁰

The third female paediatric patient was referred to the otorhinolaryngologists 7 months after excision of a left submandibular calcified mass, with diagnosis of sialolithiasis. She visited ENT emergencies at least three times after this surgery due to swelling in the left submandibular region. From her clinical history, she had episodes of left submandibular swelling without pain or postprandial discomfort.

CT and MRI with gadolinium enhancement revealed a lobulated mass with a hyperintense signal on T2-weighted images and multiple well-defined hypodense areas within the mass, consistent with phleboliths within a venous vascular malformation.

In order to reduce the size, she subsequently underwent percutaneous sclerotherapy with ethanol.¹⁰

The above-described cases have some similarities with our early adolescence.

Most cases were mentioned to venous vascular malformations (slow-flow malformations) of the submandibular area, while one paper analysed an arteriovenous dysplasia (high-flow malformation) of the floor of the mouth.

Two of the three reported paediatric patients presented with a suspected diagnosis of sialolithiasis of the submandibular gland as in our case. Only one case was referred with a mass mimicking dermoid cyst from clinical and diagnostic features.

All patients exhibited none of the symptoms of submandibular duct obstruction due to sialolithiasis, particularly no increase in submandibular gland size, pain or postprandial discomfort.

The diagnostic procedure included in all cases CT scan and MRI with the same imaging features, as detailed described. In two cases, fine-needle aspiration was performed with no high diagnostic value.

The final treatment was complete surgical excision of the lesion in two cases with no evidence of recurrence. Sclerotherapy was performed in one case and observation due to mild, asymptomatic submandibular enlargement in another one.

The final diagnosis of vascular malformation was achieved by the histological evaluation. In cases of no surgical intervention, specific imaging characteristics in CT and MRI suggested vascular malformation.

Patient’s perspective.

My parents transmitted me to the ENT outpatient department due to swelling in the left submandibular region that has been present for 3 months. I had no prior history of upper airway infection. This was the first time I visited an otorhinolaryngologist. My parents first contacted my paediatrician by phone and he diagnosed possible sialadenitis. Thus he referred me for further investigation and treatment to the otorhinolaryngologists. I had no other symptoms, only a fluctuated in size mass depending on swallowing movements without postprandial swelling and pain. I palpated a large, solitary, movable mass on the left submandibular space with no warmth or tenderness.

Learning points.

• Phlevoliths are a specific feature of venous malformations due to venous stasis.

• Phlevoliths may mimic sialoliths on various imaging modalities, and thus venous malformations are often misdiagnosed as sialadenitis due to sialolithiasis.

• Sialoliths are extremely rare in paediatric patients.

• In an early adolescent presenting with a submandibular mass and suspected sialadenitis, a detailed history, clinical examination and careful review of the radiologic findings will allow the final diagnosis of a venous vascular malformation.

• Complete surgical resection is necessary for the total cure and minimises the possibility of local recurrence.

Ethics statements

Patient consent for publication

Consent obtained from parent(s)/guardian(s).