Paraganglioma (Glomus Jugulare/Tympanicum)



Paraganglioma (Glomus Jugulare/Tympanicum)


Lester D. R. Thompson, MD





Key Facts


Terminology



  • Synonyms: Glomus jugulare, glomus tympanicum


  • Neoplasm arising from paraganglia in vicinity of jugular bulb or medial cochlea promontory


Clinical Issues



  • 10% multicentric, 10% bilateral, 10% familial


  • Female > > Male (5:1) in sporadic tumors


  • 90% of tumors of jugular foramen are paraganglioma


  • Pulsatile tinnitus


  • Hearing loss (conductive)


  • Do not biopsy: Very vascularized and will bleed


  • Presurgical embolization for reduced bleeding


  • 15% mortality due to proximity of vital anatomic structures


Image Findings



  • CT: Bone only without contrast shows a mass with flat base on cochlear promontory


  • MR T1WI: Multiple black dots in tumor indicate high-velocity flow voids


  • Octreotide or MIBG scintigraphy helps with occult or familial tumors


Microscopic Pathology



  • Clustered, zellballen architecture


  • Richly vascularized stroma, sometimes with fibrosis


  • Small to intermediate cells with ample granular, basophilic cytoplasm


Ancillary Tests



  • Neuroendocrine markers







Hematoxylin & eosin shows an intact squamous epithelium (from the EAC) subtended by a nested neoplastic proliferation associated with a rich vascularized network and fibrous connective tissue.






The zellballen arrangement gives a characteristic nesting or alveolar appearance to the neoplasm. There is focal nuclear pleomorphism image. The neoplasm is supported by a delicate vascular plexus.


TERMINOLOGY


Abbreviations



  • Glomus tympanicum paraganglioma (GTP)


  • Glomus jugulotympanicum paraganglioma (GJP)


Synonyms



  • Glomus tympanicum


  • Glomus jugulotympanicum


  • Jugulotympanic chemodectoma


  • Glomus jugulare


  • Jugular glomus tumor


  • Tympanic glomus tumor


  • “Glomus” is usually applied to smooth muscle vascular tumor of nail bed soft tissue


Definitions



  • Neoplasm arising from paraganglia in vicinity of jugular bulb or medial cochlea promontory



    • Radiographically and surgically “glomus tympanicum” (GTP) and “glomus jugulotympanicum” (GJP) paragangliomas are distinctive and unique


    • However, they are identical by pathology parameters; these clinical terms will be used for nonpathology findings


ETIOLOGY/PATHOGENESIS


Cell of Origin



  • Arises from paraganglia



    • Along inferior tympanic nerve (Jacobson nerve)


    • Around jugular foramen


    • Auricular branch of CNX (Arnold nerve)


  • Chemoreceptor cells are derived from neural crest



    • Respond to changes in blood oxygen and carbon dioxide levels


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Most common tumor of middle ear (GTP)


    • Most common tumor of jugular foramen (GJP) (˜ 90%)



      • Together GTP and GJP account for 80% of head and neck paragangliomas


    • 10% multicentric


    • 10% bilateral


    • 10% familial


    • 10% pediatric


    • 10% malignant


    • May coexist with pheochromocytoma (adrenal gland) and carotid body tumors


  • Age



    • Range: 10-85 years


    • Mean: 6th decade


  • Gender



    • Female > > Male (5:1) for sporadic tumors


    • Male > Female for inherited/familial tumors


Site



  • GTP: Middle ear surface of promontory



    • Anterior inferior quadrant of tympanic membrane


  • GJP: Jugular foramen



    • Wall of jugular bulb


Presentation



  • Pulsatile tinnitus (˜ 90% of patients)


  • Hearing loss (˜ 50% of patients)



    • Conductive rather than sensorineural


  • Vascular retrotympanic mass


  • Pain


  • Facial nerve paralysis


  • Catecholamine function is rare


  • If familial or syndrome: Autosomal dominant trait with genomic imprinting



Treatment



  • Options, risks, complications



    • Do not biopsy; very vascularized and will bleed


    • Slow growing but locally destructive tumor



      • Can be “watched” in older patients


    • Presurgical embolization for reduced bleeding


    • About 2/3 of patients experience postoperative cranial neuropathy


  • Surgical approaches



    • GTP



      • Tympanotomy for small lesions


      • Mastoidectomy for larger lesions


    • GJP



      • Infratemporal fossa approach (Fisch type A)


  • Radiation



    • May work for localized tumors


    • May be needed in combination with surgery for larger tumors


    • Palliative in poor surgical candidates or older patients


Prognosis



  • Excellent overall outcome


  • Aggressive clinical behavior is seen in ˜ 8-10% of cases


  • 15% mortality due to proximity of vital anatomic structures


  • Distant metastases are rare


IMAGE FINDINGS


General Features



  • Radiographs accurately define location, size, extent


  • Glomus tympanicum



    • CT: Bone only without contrast shows a mass with flat base on cochlear promontory


    • MR: Enhancing mass with flat base on cochlear promontory



      • Performed after bone CT yields suspicious result


  • Glomus jugulare



    • CT: Bone only shows a mass in jugular foramen with permeative-destructive change in adjacent bone


    • MR T1WI: Multiple black dots in tumor indicate high-velocity flow voids from feeder arterial branches


  • Angiography: Allows for preoperative embolization



    • Demonstrates blood supply from ascending pharyngeal artery and its branches


  • Octreotide or MIBG scintigraphy helps with occult or familial tumors


  • PET with F18 FDG: Avid uptake by tumor cells

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Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Paraganglioma (Glomus Jugulare/Tympanicum)

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