Female patient, 52 years old, with no medico-surgical background of interest, came for a consultation as a result of a slight facial asymmetry that had developed in her youth in the form a bulge in the right mandibular angle (Fig. 1) She also referred to periodic fluctuations in the size of the mass over the years that had no apparent relation with any condition or with any specific or concrete activity. On some occasions, the lesion had increased to twice the size that it had at the time. But over the last year the tumorlike mass had shown progressive growth, which had led the patient to request a consultation.

The physical examination revealed the existence of a localized tumor in the pre-masseteric area on the right side measuring 3 x 3 cm approximately in diameter. It had a soft consistency, the margins were ill defined and it was not attached to the skin or any deeper layers. The lesion was not painful to palpation. Similarly, in the center of the tumor various nodular formations could be seen that had a hard consistency. Some had a diameter that was larger than 1 centimeter. The patient carried out the Valsalva maneuver, and there was no clear increase in the size of the mass. Pulse waves could not be appreciated through the lesion.

Following MRI (axial and coronal slices) the existence of a facial asymmetry conditioned by the presence of a mass with polylobulated borders and ill-defined margins that were of soft tissue. The mass was in close contact with the right masseter muscle (the tumor-like mass being lateral and anterior to it), and it was compressed, displaced and even partially infiltrated by the lesion. Finally, nodular images compatible with calcifications (Fig. 2) could be observed within the mass. The remaining examination was normal.

B. Duarte Ruiz¹, C. Navarro Cuellar¹, R. Pujol Romanya¹, M. Cuesta Gil²

1 Médico Residente.
2 Médico Adjunto.
Servicio de Cirugía Oral y Maxilofacial.
Hospital General Universitario Gregorio Marañón. Madrid, España

Correspondencia:
Blanca Duarte Ruiz.
C/ Ibiza 66, 1º D; 28009
Madrid, España
E-mail: blancaduarte@terra.es

As it was suspected that the patient had a lesion that was clinically compatible with a masseteric angioma, complementary examinations were requested in order to help confirm the initial suspected diagnosis. Of all of these, the relevant role played by MR in the diagnosis of this type of lesion should be pointed out. In this precise case, the lesion showed a mild heterogeneous signal that was hyper-isointense with the adjacent masseter muscle on T1 and that was strongly hyperintense on T2-weighted images. Similarly, fine hyperintense lines could be observed on T1-weighted images. As mentioned previously, on the inside of the mass, nodular images could be observed with a low signal on T1 and T2- weighted images, that became clearer in the gradient echo sequences and which corresponded to calcifications. The findings corroborated by MR were compatible with the diagnosis of cavernous angioma of soft tissue, with a slight infiltration of the right masseter muscle and containing phleboliths (Figs. 2).

The classical description of the masseter region of the mouth contains the presence of the masseter and buccinator muscles, the parotid conduct, Bichat’s fat pad and cellulose adipose tissue of the anterior half of the cheek (but not therefore the parotid gland).¹ The elaboration and study of a precise diagnosis of the masses developing in this area is extremely important for radiologists as well as for the surgeons diagnosing and treating these patients in order to avoid the severe complications and important aescetic defects that arise when treating these types of lesions (with the exact clinical location often being very difficult). The object of diagnostic imaging when dealing with a mass is for determining the origin, cause and extension of the lesion before surgery.² Given the usefulness of CT scans and RM for locating a pathology in clinically inaccessible areas of the body, both tests have been used to evaluate masses of this area in particular. It is for this reason that CT scans as well as RM appear in the literature as useful and appropriate means for demonstrating the location and extension of buccomasseteric masses, in the same way that an echography would give clear and very detailed images of the structure of the interior architecture of the lesions situated in this area.²

With regard to the differential diagnosis of this type of lesion, it should be pointed out that among the pathological conditions that may lead to an enlargement or to a unilateral increase in the size of the pterygomasseteric region, we might find from neoplasia to inflammatory procedures and myopathies.³ These can all be grouped into four types of lesions: benign tumors, myopathies (masseteric hypertrophy, inflammatory processes (actinomycosis, lymphadenitis, foreign bodies, etc.) and malignant tumors or neoplasia (metastatic adenopathies, primary tumors in the region, etc.).⁴ Among the benign tumors the following should be mentioned in order of frequency, hemangiomas, lipomas, epidermal cysts, pleomorphic adenomas, Langerhans cell histiocytosis and lymphangiomas, among others. In the opinion of some authors, the most frequent pathologic condition in the buccomasseteric region is masseteric hypertrophy.⁵ On the other hand, in the study carried out by Yonetsu K and cols.³ in the year 1998 based on a study of 66 cases of masses located in the buccomasseteric area that was aimed at reviewing and illustrating the appearances on diagnostic images of the different tumor-like masses that develop in this area, it was concluded that the lesion appearing most frequently as a benign tumor is the hemangioma followed by the lipoma. A classification of the possible causes that should be considered in a differential diagnosis from the point of view of the tissue of origin in the buccomasseteric area, should include: the salivary gland (benign and malignant tumors of the salivary gland coming from the parenchyma, accessory parotid gland or of its drainage duct), inflammationsinfections (abscesses or cellulitis through specific or unspecific infection), lymphatic system (metastatic lymph node, lymphadenitis, or benign reactive lymph node, lymphoma, lymphangioma), cellulose adipose tissue (lipoma, fibroma, pseudotumor), myopathy (masseteric hypertrophy, ossifying myositis, proliferative myositis, rhabdomyosarcoma), and finally the vascular system (hemangioma, arteriovenous malformations, false aneurisms).⁵

Following the description of the pterygomasseteric region and the variety of lesions that can arise within it, and having mentioned the differential diagnosis of the masses located in this area and of the diagnostic methods involved, we will now concentrate on giving a detailed description of a concrete type of lesion situated in this area, which is at the center of this case report: the angioma.

Angiomas belong to a group of non-neoplastic vascular lesions that have a normal endothelial cell count.⁶ The origin may be arterial, venous, capillary or lymphatic (they may occur on their own or in conjunction with another entity). They are less frequent than hemangiomas (tumors characterized by the proliferation of blood vessels, that generally follow a benign course, these being the most common tumors in infancy), although they can cause problems clinically that are far more important than the latter.⁶

They are clinically distinctive as most appear at birth tending to grow with the child. After this period of growth they remain stable throughout a person’s lifetime. They can increase in size at puberty and during pregnancy, as a result of hormonal changes.⁷

Angiomas are classified according to the speed of the blood flow through the lesion, and two groups can be differentiated: Low flow and high-flow lesions.

Low flow lesions are generally venous and very varied as to their location and size. They do not disappear spontaneously and they tend to become more nodular in older patients.

On the other hand, lesions with a high flow can increase rapidly in size as a result of trauma, ligatures, and hormonal changes among others. In these circumstances patients refer an increase in body surface temperature of the lesion associated with pain and noise. As Jackson described in 1993 a hemorrhage of this type can be mortal.⁷

With regard to this type of lesion, it should be pointed out that simple radiology would only reveal the existence of a «dependent mass of soft tissue». The characteristic appearance of calcifications and phleboliths in low-flow lesions should be pointed out⁷, as occurs in the case presented. On occasions bone lesions provoked by the presence of these vascular malformations can be observed. MR as previously mentioned, shows very typical characteristics with this type of lesion, having isointense signals on T1 weighted sequences and a high signal on T2 weighted sequences. In addition MR will permit, among other things, observing the flow dynamics through the lesion and the distribution. In the CAT scan it should be pointed out that most angiomas show irregular margins. Finally, selective angiography determines the extension of the vascular lesion showing the vessels that supply the lesion with fluid and the drainage vessels.¹

With regard to treatment, it should be stressed that this is different depending on the type of lesion we are dealing with. The lesions with low flow that are large in size, such as that presented in our clinical case, can benefit from complete excision by means of conventional surgery. This can be preceded by lesion embolization during the radiological examination prior to surgical excision. Residual lesions could be treated with sclerosing agents. Very good results have been described with intralesional sodium sulphate at 3% in small low-flow lesions.

In high-flow lesions, selective embolization is rarely effective as an isolated treatment as new shunts are quickly established, although it is of great use during surgery. In addition, incomplete resection of the lesion often leads to recurrence. The ideal treatment should consist in selective embolization followed by total resection of the lesion within the first week (Jackson, 1993).⁷

With regard to the specific case of our patient, the treatment was surgical, and the angioma was completely removed prior to the dissection and preservation of the right peripheral facial nerve (buccal and marginal branch) (Figs. 3, 4 and 5). The postoperative period was favorable and there were no complications. There was only a slight paresthesia that was completely resolved after three months (Fig. 6).

References

1. Benlier E, Aydin Y, Bulan R, Erdinc B, Cetinkale O. Hemangioma in masseteric muscle. Ann Plast Surg 2002;48:219-20.        [ Links ]

2. Ariji Y, Kimura Y, Gotoh M, Sakuma S, Zhao YP, Ariji E. Blood flow in and around the masseter muscle: normal and pathologic features demonstrated by color Doppler sonography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91: 472-82.        [ Links ]

3. Yonetsu K, Nakayama E, Yuasa K, Kanda S, Ozeki S, Shinohara M. Imaging findings of some buccomasseteric masses. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;86:755-9.        [ Links ]

4. Set PA, Somers JM, Britton PD, Freer CE. Pictorial review: benign and malignant enlargement of the pterygomasseteric muscle complex. Clin Radiol 1993;48:57-60.        [ Links ]

5. Danielides V, Nousia CS, Achten E, Forsyth R, Vermeersch H. Hemangioma of the left cheek: a case report. Otolaryngol Head Neck Surg 2003;128:430-2.        [ Links ]

6. Ho-Asjoe M, Tatla T, Carver N. Parotid haemangioma: an unusual presentation. Br J Plast Surg 2003;56:73-4.        [ Links ]

7. Kurabayashi T, Ida M, Tetsumura A, Ohbayashi N, Yasumoto M, Sasaki T. MR imaging of benign and malignant lesions in the buccal space. Dentomaxillofac Radiol 2002;31:344-9.        [ Links ]