Evaluation of Head and Neck Paragangliomas by Computed Tomography in Patients with Pheochromocytoma-Paraganglioma Syndromes

Abstract

Background: Hereditary head and neck paragangliomas (HNP) are very often associated with pheochromocytoma-paraganglioma syndromes, which are caused by mutations in genes encoding subunits of succinate dehydrogenase (SDHx) complex. The aim of this study was to determine the frequency and location of HNP among SDHx carriers.

Material/methods: A total of 72 patients with SDHx mutations underwent computed tomography examinations of the head and neck. HNP were present in 44 (61.1%) out of 72 patients (31 SDHD, 11 SDHB, 2 SDHC); 113 HNP were found; the most common were carotid paragangliomas (59) and vagal paragangliomas (27).

Results: The HNP were statistically more frequent in carriers of SDHD mutations compared to carriers of SDHB mutations (72.1% vs. 43.5%, p=0.033). Multiple tumors more often occurred in patients with SDHD mutations 26/31 (83.9%) than in patients with SDHB mutations 6/11 (54.5%) p=0.05. There was a significant difference in the prevalence of carotid paragangliomas between patients with SDHB and SDHD mutations (7/11 [63.6%] vs. 30/31 [96.8%], respectively, p=0.004). Patients with SDHD mutations more often had carotid paragangliomas located on the left side than on the right side, as compared to SDHB mutations 25/31 (80.6%) vs. 4/11 (36.4%), p=0.006.

Conclusions: SDHx mutations predispose to multifocal and bilateral HNP. Carotid and vagal paragangliomas occurred most often. Patients with SDHD mutations are characterized by higher frequency of HNP than patients with SDHB mutations, which is mainly driven by higher frequency of carotid body tumors in patients with SDHD mutations. No difference in the frequency of head and neck paragangliomas in other locations was found.

Keywords: Carotid Body Tumor; Head and Neck Neoplasms; Paraganglioma, Extra-Adrenal; Succinate Dehydrogenase.

Figure 1

Carotid paraganglioma in a 32-year-old man with SDHD mutation. Contrast-enhanced CT, sagittal view, MIP reconstruction shows an intensely-enhancing mass in the left carotid bifurcation (arrow).

Figure 2

Vagal paraganglioma in a 47-year-old man with SDHB mutation. Contrast-enhanced CT, MIP reconstruction, sagittal view shows an enhancing mass (arrow) causing displacement of the internal carotid artery anteriorly.

Figure 3

Comparison of carotid paragangliomas according Shamblin classification in patients with SDHB and SDHD mutations.

Figure 4

A 37-year-old man with malignancy SDHB mutation. (A, B) Contrast-enhanced CT, a-coronal, b-axial view, showing well-enhanced tumor mass extending from the carotid bifurcation to the left tympanum (arrows). (C, D) CT, axial views show osteoblastic metastases to the thoracic vertebrae and to the left occipital and sphenoid bones (arrows).