CASE 15320 Published on 05.02.2018

CT and MRI findings in a case of carotid body paraganglioma

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

Dr Shailesh Bhuriya¹; Dr Amit Achyut Ban¹; Dr Nandini Bahri ²; Dr Jay Satapara¹

1. Resident
2. Professor and Head of Department
Department of Radio-diagnosis,
Shri M P Shah Medical College,
G G Hospital,
Jamnagar, Gujarat, India.
Email ID: amit23ban@gmail.com

Patient

30 years, male

Categories

Area of Interest Head and neck ; Imaging Technique CT, MR

Procedure Diagnostic procedure ; Special Focus Neoplasia ;

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Clinical History

A 30-year-old male patient presented complaining of throat pain and difficulty in swallowing for 1 month. On examination a mucosal bulge was noted on the right pharyngeal wall.

Imaging Findings

Contrast-enhanced CT evaluation revealed a well-defined, ovoid, homogeneously enhancing soft tissue density mass involving the right carotid space (Fig. 2, 3, 4). The lesion caused splaying of right internal and external carotid artery (Fig. 2c; 4c, d; 5). The location of the lesion was confirmed by lateral displacement of the styloid process (Fig. 2a - red arrow), anterior displacement of para-pharyngeal fat (Fig. 2a - blue arrow) and medial displacement of the right pharyngeal wall (Fig. 2a - yellow arrow).

Non-contrast MRI evaluation revealed a well-defined lesion, isointense on T1-weighted imaging and hyperintense on T2-weighted imaging, involving the right carotid space (Fig. 3, 4). T2-weighted imaging showed typical 'salt and pepper' appearance (Fig. 3a, b).

Discussion

Paraganglioma are tumours arising from paraganglia (non-neuronal cells derived from neural crest cells) anywhere in the body [1, 2]. Common locations include the carotid body, vagus nerve in the head and neck region, jugular foramen, middle ear, aorto-pulmonary window and organ of Zuckerkandl. They comprise 0.6 % of all head and neck neoplasms [3]. Carotid body and jugular foramen paragangliomas account for 80% of paragangliomas in head and neck [4].

They can present as sporadic and familial forms. The sporadic form is commonly seen in the 45-50 year age group with no gender predilection [5, 6]. Its aetiology is unknown. Lesions present as a slow growing, painless lateral neck mass. Associated symptoms include cranial nerve palsies, change in voice and hearing loss [5, 7, 10]. The familial form, usually presenting bilaterally, accounts for 10% of cases and is inherited as a component of multiple endocrine neoplasia, tuberous sclerosis, neurofibromatosis and von Hippel-Lindau syndrome.

Paragangliomas in general show homogeneous and intense enhancement after IV administration of contrast material because of their hyper-vascularity. T2- weighted MR imaging shows the presence of a hyperintense mass with internal hypointense areas giving a 'salt-and-pepper' appearance. 'Salt' denotes hyperintense areas of haemorrhage whereas 'pepper' denotes hypointense vascular flow voids [11]. Splaying of the internal and external carotid arteries demonstrated on contrast-enhanced CT and angiography is known as the lyre sign, consistent with a carotid body tumour [12]. Angiographic confirmation of hypervascularity is noted as intense tumour blush. Thus, a salt-and-pepper appearance on MRI, splaying of internal and external carotid vessel and tumoral hyper-vascularity clinch the diagnosis of carotid body paraganglioma [17, 18].

The differential diagnosis includes vagal paraganglioma and nerve sheath tumour. Vagal paraganglioma tends to displace both the external and internal carotid arteries antero-medially [13, 14]. Nerve sheath tumours also displace both arteries antero-medially but lack the hypervascularity of a paraganglioma.

Surgical excision is the treatment of choice. Preoperative angiography is useful for surgical planning and preoperative embolisation [11, 15]. Embolisation promotes tumour shrinkage and reduces blood loss during surgery. Radiotherapy may be considered where surgery is not an option or indicated.

Teaching point: Carotid body paraganglioma can be readily diagnosed based on its CT, MRI and angiographic appearances.

Differential Diagnosis List

Carotid body paraganglioma

Vagal paraganglioma

Pathological lymph node

Nerve sheath tumour

Final Diagnosis

Carotid body paraganglioma

References

[1] Lattes R (1950) Nonchromaffin paraganglioma of ganglion nodosum, carotid body, and aortic-arch bodies. Cancer 3:667-694 (PMID: 15427070)

[2] Kliewer KE, Cochran AJ (1989) A review of the histology, ultrastructure, immunohistology, and molecular biology of extra-adrenal paragangliomas. Arch Pathol Lab Med 113:1209–1218 (PMID: 2684087)

[3] Borba LA, Al-Mefty O (1996) Intravagal paragangliomas: report of four cases. Neurosurgery 38:569–575 (PMID: 8837811)

[4] Kliewer KE, Wen D-R, Cancilla PA, Cochran AJ (1989) Paragangliomas: assessment of prognosis by histologic, immunohistochemical, and ultrastructural techniques. Hum Pathol 20:29–39 (PMID: 2912871)

[5] Gad Amr, Sayed Ahmed (2014) Carotid body tumors: a review of 25 years experience in diagnosis and management of 56 tumors. Ann Vasc Dis 7(3):292–299 (PMID: 25298832)

[6] Kay JM, Laidler P (1977) Hypoxia and the carotid body. J Clin Pathol Suppl (R Coll Pathol) 11:30–44 (PMID: 198435)

[7] Wienek Jacqueline A, Smith Alice (2009) Paraganglioma: carotid body tumor. Head Neck Pathol 3(4):303–306 (PMID: 20016787)

[8] Hensen Erik F, Bayley Jean-Pierre (2011) Recent advances in the genetics of SDH-related paraganglioma and pheochromocytoma. Fam Cancer 10(2):355–363 (PMID: 21082267)

[9] Baez Juan C, Jagannathan Jyoyhi P (2012) Pheochromocytoma and paraganglioma: imaging characteristics. Cancer Imaging 12 (1):153–162 (PMID: 22571874)

[10] Boedeker Carsten Christol (2011) Paragangliomas and Paraganglioma Syndromes. GMS Curr Top Otorhinolaryngol Head Neck Surg 10 : Doc 03 (PMID: 22558053)

[11] Olsen WL, Dillon WP, Kelly WM, Norman D, Brant-Zawadzki M, Newton TH (1987) MR imaging of paragangliomas. AJR 148:201–204 (PMID: 3024473)

[12] Som PM, Sacher M, Stollman AL, Biller HF, Lawson W (1988) Common tumors of the para-pharyngeal space: refined imaging diagnosis. Radiology 169:81–85 (PMID: 2843942)

[13] Rao AB, Koeller KK, Adair CF (1999) From the archives of the AFIP; Paragangliomas of the head and neck: radiologic–pathologic correlation. Radiographics 19:1605–1632 (PMID: 10555678)

[14] Som PM, Biller HF, Lawson W, Sacher M, Lanzieri CF (1984) Para-pharyngeal space masses: an updated protocol based upon 104 cases. Radiology 153:149–156 (PMID: 6089262)

[15] Duncan AW, Lack EE, Deck MF (1979) Radiological evaluation of paragangliomas of the head and neck. Radiology 132:99–105 (PMID: 451228)

[16] Elisabetta Zanoletti, Antonio Mazzoni. (2006) Vagal Paraganglioma. Skull Base 16:161-168 (PMID: 1586175)

[17] A.B Rao, Kelly K. Koeller, Carol F. Adair (1999) From the Archives of the AFIP. Paragangliomas of the Head and Neck: radiologic-pathologic correlation. Radiographics 19:1605-1632 (PMID: 10555678)

[18] Grotemeyer D1, Loghmanieh SM, Pourhassan S, Sagban TA, Iskandar F, Reinecke P, Sandmann W. (2009) Dignity of carotid body tumors. Review of the literature and clinical experiences. Chirurg 80(9):854-63 (PMID: 19458915)

Case information

URL:	https://www.eurorad.org/case/15320
DOI:	10.1594/EURORAD/CASE.15320
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

CT images

Plain CT axial image shows lateral displacement of styloid process (red arrow), anterior displacement of para-pharyngeal fat (blue arrow) and medial displacement of pharyngeal wall (yellow arrow) on right side suggestive of carotid space lesion.

Contrast-enhanced CT axial image shows a homogeneously enhancing mass (red arrow) arising from right carotid space.

Contrast-enhanced CT sagittal image shows a homogeneously enhancing lesion (red arrow) causing splaying of external (blue arrow) and internal (green arrow) carotid arteries.

Contrast-enhanced CT coronal image shows a homogeneously enhancing lesion (red arrow) in the right carotid space.

Figure 2

Common locations of head and neck paragangliomas

Four common sites are carotid body at common carotid artery, jugular foramen, along vagus nerve and within middle ear.

Figure 3

MR images

T1-weighted image shows an isointense lesion in the right carotid space. Hypointense areas are suggestive of signal voids of intratumoral vessels.

T2-weighted image shows the typical salt and pepper appearance of the lesion. Hyperintense areas denote haemorrhage (salt) and hypointense areas (yellow arrows) denote signal voids of intratumoral vessels (pepper).

T2-weighted sagittal image shows a hyperintense lesion (red arrow) with a salt and pepper appearance.

T2-weighted coronal image shows a hyperintense lesion (red arrow) with salt and pepper appearance.

Figure 4

MR T2-weighted sequential STIR images for carotid splaying

Red arrow shows the common carotid on the right side.

Red arrow demarcates the division of the common carotid artery into external and internal carotid arteries.

Note the hyperintense lesion (blue arrow) between the external carotid (green arrow) and internal carotid (red arrow) arteries.

Note the hyperintense lesion (blue arrow) between the external carotid (green arrow) and internal carotid (red arrow) arteries causing splaying of the vessels.

Figure 5

MIP reformatted images of CT neck