Abstract
Introduction
Jugular paraganglioma is a rare, highly vascular neuroendocrine tumor arising from paraganglia of the head and neck that is located at the jugular fossa. Because of their complex location, early diagnosis and assessment are important for treatment planning. This case report demonstrates jugular paraganglioma, with an enhancing right jugular-foramen mass on MRI, bone erosion on CT, and intense radiotracer uptake on 68Ga-DOTATATE PET/CT.
Case Info
The patient was a 92-year-old man with profound right-sided sensorineural hearing loss managed with a CROS hearing aid and lacked symptoms of hormone hypersecretion. Imaging demonstrated a right jugular foramen mass consistent with a jugular paraganglioma. The mass involved the vertical and horizontal portions of the carotid canal and tympanic cavity, with small extension into the neck and no intracranial extension. T2 FLAIR demonstrated mild hyperintense signal with associated right sided mastoid effusion, while T2 had few punctate signal voids. Pre-contrast T1 showed mild hyperintensity, which may be due to slow flowing blood, hemorrhage, or proteinaceous content. Post-contrast T1 revealed avid enhancement of the tumor measuring 28 x 18mm and mildly increased in size since 2017. Additionally, CT temporal bone demonstrated erosive changes at the anterior and medial walls of the right jugular foramen. 68Ga-DOTATATE PET/CT showed intense abnormal radiotracer uptake corresponding to the known mass, confirming jugular paraganglioma. Given his high level of functioning, absence of cranial neuropathies, and age, observation of the tumor was pursued.
Disc Clinical
Paragangliomas, or glomus tumors, are divided into sympathetic and parasympathetic groups. Sympathetic paragangliomas, located in the chest and abdomen, present with symptoms of catecholamine excess. Parasympathetic paragangliomas, located in the head and neck, present with tinnitus, hearing loss, cranial nerve palsies or a palpable neck mass. The most common head and neck paraganglioma is the carotid body tumor and second most common is jugular paraganglioma. This patient had a jugular paraganglioma, a locally infiltrative tumor that may be bilateral or coexist with other tumors but rarely metastasizes.
For imaging of jugular paragangliomas, CT is best for assessing irregularly eroded bony margins and moth-eaten appearance. Angiography shows intense tumor blush commonly from the ascending pharyngeal artery. MRI demonstrates low T1 signal, high T2 signal, and marked intense enhancement on post-contrast T1. On T1 and T2, the salt and pepper appearance is visible, with salt describing blood products from hemorrhage or slow flow and pepper representing flow voids due to high vascularity. Lastly, 68Ga-DOTATATE PET/CT is useful for detecting paragangliomas because these tumors overexpress somatostatin receptors, particularly SSTR2, resulting in intense radiotracer uptake.
Differential diagnosis includes jugular schwannoma, bony metastases, meningioma, normal anatomic variation, jugular bulb thrombosis, and endolymphatic sac tumor. In this patient, the combination of irregular bone erosion, avid enhancement, vascular flow voids, and intense 68Ga-DOTATATE uptake supported jugular paraganglioma over these other diagnoses.
Conclusion
Jugular paraganglioma is a rare, highly vascular tumor that can be differentiated from other head and neck lesions by its characteristic findings on CT, MRI, and 68Ga-DOTATATE PET/CT. Recognizing these imaging features is important for diagnosis and treatment planning.