A Rare Clinical Report of Intramuscular Hemangioma of the Middle Scalene Muscle

Abstract

Intramuscular hemangioma (IMH) is an uncommon benign vascular lesion, which develops in skeletal muscles and it accounts for <1% of all hemangiomas. The accurate diagnosis is often difficult because the clinical and radiological findings are not specific. The gold standard treatment of IMH is surgical resection. We present a rare clinical report of IMH of the middle scalene muscle that was treated successfully with preoparative embolization and surgical excision.

Case Description

A 26-year-old man was referred to our ear, nose, and throat (ENT) department with a 4-year history of a right-sided growing neck mass. This mass was firstly observed in childhood. It started growing up suddenly after intense weight training 4 years ago. The mass was treated with a partial excision which was performed in another hospital. There were no preoperative radiological images and there was no clinical suspicion of IMH. The mass was partially resected due to the bleeding, which was controlled by bipolar diathermy. The histopathological diagnosis was IMH. The patient had a family history of hemangiomas, from his mother’s side. When the patient presented to our department, he had functional disabilities, such as difficulty in head movements and swallowing. Moreover, the mass was huge, painless, mobile and was located in the posterior cervical triangle. No other hemangioma was revealed at any other location in patient’s body from the clinical examination.

Magnetic resonance imaging (MRI) revealed a hypervascular mass (12.4 cm × 9.6 cm × 8.9 cm), with hypointense signal void on T1-weighted images and hyperintense signal void on T2-weighted images, with close relationship with the middle scalene muscle fibers (Figure 1). Computed tomography angiography (CTA) demonstrated that the mass was fed by branches of the right thyrocervical and costocervical trunks (Figure 2). Digital subtraction angiography (DSA) and tumor embolization were performed 2 days before the complete surgical resection (Figure 1). Ιntraoperatively, the tumor was found that was arising from the middle scalene muscle. The postoperative and the 5-month follow-up period was without complications or recurrence of IMH. Histopathological examination confirmed the diagnosis of IMH (Figure 3).

Figure 1.

Magnetic resonance (A, B) and digital subtraction angiography (DSA) images (C). Magnetic resonance imaging (MRI) showing a well-defined mass in the posterior cervical triangle, with (A) hypointense signal voiding on T1 axial section, (B) hyperintense signal voiding on T2 coronal section, and closely relationship with the right middle scalene muscle fibers (green arrows: middle scalene muscle). (C) Digital subtraction angiography image after embolization of the right thyrocervical and costocervical trunks.

Figure 2.

Computed tomography angiography (CTA) with 3D reconstruction showing a hypervascular mass 12.4 cm × 9.6 cm × 8.9 cm in size.

Figure 3.

Histopathological examination demonstrating intramuscular hemangioma. a: skeletal muscle fibers, b: vessels, c: adipose tissue (H&E, ×10), H&E indicates hematoxylin and eosin.

Discussion

Intramuscular hemangioma is a benign vascular tumor that generally occurs in the extremities and chest wall, accounts for about 1% of all hemangiomas.^1,2 Liston was the first who described an IMH, in 1843, as a benign and congenital neoplasm localized to the muscles of the lower extremity. ³ Rarely, IMH develops in the head and neck region (14%-21% of all IMHs); the most common sites being the masseter and trapezius muscles, followed by the sternocleidomastoid, mylohyoid, temporalis, and orbital muscles.^4,5 Intramuscular hemangioma that originates from scalene muscles are rarely seen. Only 7 clinical reports of IMH of scalene muscles have been described in the literature.^4-9 One of these was located in the posterior scalene, 1 in middle scalene, 2 in the anterior scalene, and the other 3 originated from unspecified scalene muscles.^4-9 This is the eighth clinical report of IMH of scalene muscles in the literature.

These tumors more often occur in adolescents and young adults and do not differ significantly in gender predominance. ¹ Regarding the etiology, the leading cause of IMHs is due to traumatic reasons; however, they can also be congenital or endocrinological. ⁵ Intramuscular hemangioma presents as a localized, soft, mobile, well-defined, fluctuant mass. They differ from other types of hemangiomas due to the lack of findings such as thrill, discoloration on the skin, or pulsation. In addition, the compression by the growing tumor may cause pain; our patient was pain free. ⁷ Differential diagnosis of neck masses with these clinical signs includes lymphadenopathy, paragangliomas, branchial cysts, lymphangiomas, schwannomas, rhabdomyosarcomas, arteriovenous malformation, or myositis ossificans. ¹⁰

Preoperative diagnosis of IMH is difficult and risky with core biopsy or fine needle aspiration cytology due to possible bleeding. Diagnosis is mostly based on imaging data. Undoubtedly, MRI is a preferred examination; IMH has a hypointense signal voiding in T1-weighted images and hyperintense signal voiding in T2-weighted images and is also characterized by extensive enhancement in gadolinium-enhanced MRI. ² Although, CT and ultrasonography are important examinations; angiography, especially DSA, is distinctly superior because it can detect feeding vessels of IMH.

The treatment of choice for IMH is surgical resection. Moreover, preoperative embolization could be helpful for the intraoperative bleeding control. However, some authors recommend observation in small size IMH. ¹¹