Tortuous Innominate Artery Simulating a Supraclavicular Subcutaneous Tumour
Tohru Tanigawa1, Atsushi Shinohara2, Takashi Sato3, Jun-ichi Yamashita4 and Shigeru Inafuku1
1Department of Otolaryngology, Aichi Medical University, 2Department of Oral and Maxillofacial Surgery, Aichi Medical University, 3Department of Otolaryngology, Aichi Gakuin University and 4Department of Breast Oncology, Okazaki City Medical Association Public Health Center, Aichi, Japan. E-mail: firstname.lastname@example.org
Accepted September 8, 2008.
When a subcutaneous mass is noticed in the anterior neck of a patient, we usually consider a diagnosis of skin tumour, lymph node swelling (1), or thyroid tumour (2). Vascular diseases, such as a tortuous major artery, aneurysm, or haemangioma are extremely rare (3–7).
We describe here a case of a right tortuous innominate artery in which it proved impossible to detect pulsation because of the skeleto-muscular structures shielding the affected area. If either an aspiration or an open biopsy were to be performed near a tortuous innominate artery simulating a subcutaneous mass, a major artery might be damaged, possibly with lethal consequences. We present here clinical findings that call for caution in dealing with a tortuous innominate artery simulating a supraclavicular subcutaneous tumour.
A 73-year-old woman presented at our hospital complaining of an anterior neck mass that she had noticed only 4 weeks previously. She was not obese (BMI = 19.3), nor was her medical history regarding hypertension, hyperlipidaemia and syphilis particularly remarkable. She had no dyspnoea or dysphagia, but her husky voice and severe throat discomfort were clearly alarming. A fibroscopic examination revealed no abnormality in the pharynx or larynx. We palpated a 1.5-cm subcutaneous mass in the right supraclavicular fossa (Fig. 1), but were unable to detect any obvious pulsation of the mass. Ultrasonography revealed that our access to a view within the mass was blocked by the clavicle, which covered the lower part of the mass. Computerized tomography (CT) showed a tortuous innominate artery protruding from the mediastinal space (Fig. 2A). In addition, magnetic resonance angiography (MRA) revealed that the forward and lateral arterial bending becomes the substance of the mass (Fig. 2B). From these examinations, we diagnosed it as a tortuous innominate artery simulating a subcutaneous neck tumour. Since her symptoms were not accompanied by neurological signs, we kept the patient under careful observation for 12 months.
Fig. 1. A mass in the right supraclavicular fossa with the appearance of a subcutaneous tumour (arrow). Pulsation of the mass could not be detected clearly because of the patient’s normal blood pressure.
Fig. 2. (A) Computed tomography (axial image) demonstrated a tortuous innominate artery (arrow) markedly protruding from the mediastinal space into the subcutaneous tissue of the anterior neck. (B) Magnetic resonance angiography revealed that the forward and lateral arterial bending becomes the substance of the mass.
This case revealed a tortuous innominate artery, which had initially been observed as a subcutaneous mass within a supraclavicular lesion. We could detect no obvious pulsation of the mass, but subsequent CT and magnetic resonance imaging (MRI) revealed a tortuous innominate artery. From our experience, when a subcutaneous tumour occurs near the clavicle, one should look for signs of an abnormal course of the innominate arteries, since their evanescent character is related to blood pressure levels (4). Initially, a radiological survey including CT, MRI, or MRA should be conducted.
If a subcutaneous tumour occurs above the clavicle, or if the clavicle shields the mass, it is difficult to obtain detailed information about the evanescent mass by palpation or ultrasonography alone. In addition, Polachek (2) reported on a patient with a tortuous innominate artery that was compressing the right lobe of the thyroid, resulting in atrophy of its lower portion. In that case, a diagnosis of thyroid tumour had been discounted since a cold nodule of the right lobe was detected with 131I scintigraphy. Buck & Siddiqui (8) reported on a tortuous carotid artery that raised the thyroid gland, thus simulating a thyroid nodule. Such reports suggest that there are occasional difficulties in distinguishing between aberrant arteries and tumour masses.
In the management of a tortuous innominate artery, careful attention should be paid to vascular anomalies if the patient has to undergo a tracheotomy. In cases of emergent tracheotomy (5) and/or percutaneous dilational tracheostomy (9), in particular, the utmost care should be taken not to damage major aberrant vessels by mistake. We think that had a tracheotomy been indicated in our case, we would have first used Doppler ultrasonography to confirm that the pulsating sound of a tortuous innominate artery could not be heard.
The pathogenesis of a tortuous or kinking innominate artery is unclear. Such diseases often accompany hypertension and obesity in middle-aged women. Moreover, arteriosclerotic changes due to hyperlipaemia have also been suggested (3). However, we speculate that decreased elasticity of the vascular walls due to ageing is one of the causes of this abnormality. We have also speculated as to whether another cause might be a congenital deformity of the artery, since neither hypertension nor obesity were involved in our case.
Successful surgical corrections of tortuous neck arteries have been reported (3). However, as long as the patient shows no cerebrovascular signs, and no stenosis or aneurysm of the artery is involved, many reports have recommended no surgical treatment (10). Our case showed no cerebrovascular ischaemic signs, and a strict follow-up schedule was implemented.
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