Paediatric Masseter Hemangioma with Facial Nerve Involvement: A Diagnostic and Therapeutic Challenge

Abstract

Intramuscular haemangioma of the masseter muscle is an infrequent entity which is often misdiagnosed because of lack of symptoms. The rarity, asymptomatic indolent character and deep seated location makes these swelling a diagnostic dilemma and therapeutic challenge. This case report is an appraisal of the diagnosis and management of intramuscular masseteric haemangioma from an otolaryngological perspective and is being reported here for its rarity, inherent surgical challenge and academic interest. We report a case of intramuscular haemangioma of right side masseter muscle in a 10-year-old boy. The atypical indolent asymptomatic slow growth pattern and gradual involvement of facial nerve in this case warrants the necessity of reporting this case. We performed surgical excision of intra masseteric hemangioma with preservation of involved peripheral facial nerve branches. The peculiarity of the case gives insight into different types of presentation of pediatric haemangioma. The involvement of peripheral facial nerve branches in the swelling highlights the surgical dexterity involved in complete removal of head and neck haemangioma. It is important to identify such cases with thorough check up and high degree of suspicion by a clinician while dealing with such presentation. The treatment modality adopted should be based on individual clinical status of the patient.

Introduction

Haemangiomas are benign vascular tumors. Haemangiomas often present as tumours of infancy with predominantly cutaneous and mucosal manifestations. Intramuscular haemangiomas are rare entities accounting for less than 1% of all cases of hemangiomas [1]. These intramuscular hemangiomas occur most commonly in trunk and extremities and only 10–20% infrequently present in head and neck region [2]. The rarity, asymptomatic indolent character and deep seated location make these swelling a diagnostic dilemma and therapeutic challenge.

Case Report

A 10-year-old male patient presented to our outpatient department with gradually progressive right sided cheek swelling. The swelling was initially unnoticed until 3 years prior to presentation, during which progressive asymmetry of the cheeks became apparent, finally leading the parents to seek medical attention. Local examination revealed a non tender swelling without rise in local temperature and no change in the texture and colour of the overlying skin. The swelling was solitary, firm and well circumscribed. No bruit or thrill was apparent. Careful examination of facial nerve revealed a low grade facial nerve palsy of the involved side. The swelling became more prominent and well-defined on clenching of teeth and was more mobile along the horizontal as compared to the vertical axis (Fig. 1).

Fig. 1.

Right sided cheek swelling

Subsequent radiological investigations were performed and the swelling was provisionally diagnosed to be a haemangioma involving the right masseter muscle on ultrasonography and colour Doppler. Magnetic Resonance Imaging (MRI) showed a space-occupying lesion in the right masseter muscle, with intermediate signal intensity on T1-weighted images and hyperintensity on T2-weighted images, containing nodular hypointense foci corresponding to calcification. Fine needle aspiration cytology from the cheek swelling yielded a blood aspirate. All the routine hematological investigation were found to be within normal limits. General examination and other systemic examination were found to be normal. Thus, a presumptive diagnosis of an intra masseteric hemangioma with phlebolith was made based on these findings (Fig. 2).

Fig. 2.

Short T1-Inversion Recovery Magnetic Resonance Images. a Axial, b Sagittal and c Coronal views demonstrate an enhancing lesion with flow-void in the right master muscle (as shown by the arrows)

Patient was posted for surgery after proper counselling and after obtaining required consent, surgical excision by Modified Blair’s incision under general anesthesia was done. Superficial cervicofascial flap was raised and after identification of landmarks for facial nerve sharp dissection was done to expose the parotid and the masseteric swelling. The peripheral branches of facial nerve exiting the parotid gland were seen to be involved within the masseteric swelling. The swelling on gross examination appeared to be a hemangiomatous mass. The small feeding vessels were ligated and careful dissection was made to anchor the peripheral branches of the facial nerve off the swelling following which it was completely delivered out (Fig. 3). The wound site was filled with absorbable gel foam to reduce the future risk of hematoma formation and a drain was placed. Incision was closed in layers. The post-operative period was uneventful and facial nerve paralysis (House-Brackman grade -II) gradually improved after surgery. The histopathological examination of the excised specimen confirmed the diagnosis of hemangioma. There was no recurrence during an observation period of 6 months.

Fig. 3.

Anchoring of peripheral facial nerve branches around the mass

Discussion

Intramuscular hemangiomas are rare, benign tumors of vascular origin which are very infrequent in occurrence. The involvement of masseter muscle in intramuscular hemangiomas constitute about 5% of all such cases with trapezius, sternocleidomastoid, and temporalis muscle being other atypical sites of involvement [3]. The tongue, extra-ocular, and posterior neck muscles have also been reported to be involved with hemangioma, with less frequency [4]. The most frequent age of presentation is adolescence with an equal sex distribution. However, involvement of the masseter muscle has a definite male predominance in some series [5].

In 1843, Liston was the first to report a case of intramuscular cavernous haemangioma naming it as an "erectile tumor" [6]. Intra muscular haemangiomas are considered hamartomatous lesions and thought to arise from abnormal embryonic rests. Developmentally, intramuscular haemangiomas represent congenital vascular malformations. They generally develop in patients during the first three decades of life with no gender predisposition [5]. Intramuscular haemangioma are believed to be benign, hamartomatous, congenital neoplasm that go undetected for long period of time until sudden growth gives rise to pain or cosmetic deformity as in the present case [6,7].

Intra masseteric haemangiomas are reported to be generally painless, gradually enlarging lesions which do not display overt features of being a vascular lesion. Masseter is a powerful muscle of mastication and one of the strongest muscles based on its weight. Hence deep seated intra masseteric hemangiomas demonstrate no features such as pulsations, thrills or bruits and discolouration of overlying skin is also uncommon. The absence of pathognomic clinical findings and rarity of its presentation make the pre operative diagnosis exceedingly tricky. The list of puzzling differential diagnosis includes muscle neoplasm, parotid lesions, masseteric muscular hypertrophy, cysts and lymphadenopathy. Thus, the role of pathological and radiographic investigations becomes paramount to evaluate intra masseteric haemangiomas pre operatively.

Features of rich vascularity and high blood flow velocity distinguish hemangioma from other soft tissue lesions. The utility of conventional radiographs is not specific though the presence of phleboliths may be identified in the lesion. Ultrasound with colour Doppler and magnetic resonance imaging (MRI) are the preferred modalities of radiographic investigations. Colour Doppler signal in a well defined hypoechoic mass with heterogeneous echotexture should raise the possibility of hemangioma [8]. MRI is considered the most powerful diagnostic tool and it is highly suspicious if the mass shows high signal in T2-weighted image and a non-homogenous appearance [9]. Marked hyperintensity of the lesions on T2-weighted images is due to increased fluid content secondary to stagnant blood flow in large vessels [10]. MRI becomes especially useful to diagnose deep situated and intra muscular hemangiomas like a masseteric hemangioma. Radiological presence of phleboliths has diagnostic value in such haemangiomas. However, the presence of calcification in hemangiomas ranges from 15 to 25% only [11]. Pre-operative Fine Needle Aspiration Cytology (FNAC) mostly reveals blood aspirate and may not be always be a useful diagnostic tool. However, post operative histopathology of the specimen not only confirms the diagnosis but also classifies the lesion in different subtypes namely capillary, cavernous and mixed haemangiomas. While capillary is the commonest subtype, cavernous haemangiomas are generally large, deeply located, intramuscular, diagnosed later in life and do not have spontaneous involution [7].

Various management options for the management of pediatric head and neck haemangiomas have been suggested in literature. It includes watchful follow up for self-involution, sclerotherapy, propranolol therapy, steroid therapy, cryotherapy and electrocoagulation. Embolization has also utilized for treatment of head and neck lesions for symptomatic relief in case when surgery cannot be offered. They can only be as an adjunctive to medical or surgical treatment. It is prudent to individualize management of such cases according to the size and anatomic accessibility of the tumor, its growth rate, age of the patient, and cosmetic and functional considerations in each and every case [12]. As it is unusual for deep seated intramuscular haemangiomas to spontaneously regress, surgical excision of these hemangiomas if surgically accessible should be the preferred mode of treatment. Wide surgical resection with a margin of normal tissue owing to the infiltrative nature of these lesions is generally employed to manage intra masseteric hemangiomas. Recurrences however, are not uncommon. Sclerotherapy is recommended in cases where surgical resection is not possible.

Preoperative diagnosis of intramuscular haemangioma with facial nerve involvement is a challenge; however, it is extremely important since post-operative palsy is common and can often be of higher grade if handled hastily.

Our case presented the diagnostic challenge to rule out various differentials. The list of differential diagnosis included buccal node lymphadenopathy, masseteric hypertrophy, accessory parotid lesion, lymphovascular tumours & congenital cysts among others. We utilized detailed history and clinical examination aided with appropriate radiological to reach the working diagnosis of intra masseteric hemangioma. Surgical excision was planned and undertaken after proper counseling. Involvement of facial nerve within the lesion presented a surgical challenge which was overcome with meticulous dissection. Improvement of facial nerve function in post-operative period validated our treatment protocol.

Conclusion

The diagnosis of intramuscular hemangiomas should be considered as a possibility in any soft tissue lesion in a skeletal muscle. Use of appropriate radiological investigation enhances the accuracy of pre-operative diagnosis. The treatment modality adopted should be based on individual clinical status of the patient.

Compliance with Ethical Standards

Conflict of interest

The authors declare that there is no conflict of interest.