Paraganglioma



Paraganglioma


Nina Gale, MD

Cyril Fisher, MD, DSc, FRCPath









Hematoxylin & eosin shows the characteristic alveolar pattern (zellballen) of paraganglioma. Small nests of cells image are surrounded by a fibrovascular, richly vascularized stroma.






Synaptophysin shows strong and diffuse immunoreactivity of the chief cells image. There is no reactivity of the supporting sustentacular cells (which would stain with S100 protein).


TERMINOLOGY


Synonyms



  • Chemodectoma


  • Glomus (do not confuse with soft tissue glomus)


Definitions



  • Neuroendocrine tumor arising from paraganglia at specified locations


  • Chromaffin(+) tumors resemble pheochromocytoma



    • Aorticosympathetic, can be functional


  • Chemoreceptor (branchiomeric) type are nonchromaffin



    • Usually nonfunctional


  • Chief and sustentacular cells arranged in organoid pattern


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Sporadic or familial



      • Germline mutations include succinate dehydrogenase gene SDH


      • Can be part of MEN2, Carney triad, or NF1


      • Many familial lesions are multifocal


  • Age



    • Any age but mostly adults


  • Gender



    • M > F for carotid body tumors


    • Slight female predominance in other sites


Site



  • Head and neck



    • Carotid body is most common site



      • > 1/2 of head and neck paragangliomas


      • More common in high-altitude habitat


    • Jugular bulb, middle ear


    • Vagus nerve


  • Mediastinum (aorticopulmonary)


  • Retroperitoneum (from/aorticosympathetic paraganglia or organ of Zuckerkandl)


  • Organ-based



    • Duodenum (gangliocytic paraganglioma)


    • Bladder, heart, larynx


Presentation



  • Painless mass



    • Pressure effect


  • Vagal symptoms


Treatment



  • Surgical approaches



    • Surgical excision with external approach



      • Intraoperative bleeding may be significant


Prognosis



  • Most benign but can recur


  • Rare malignant examples



    • Metastasize to lymph nodes, lung, bone


MACROSCOPIC FEATURES


General Features



  • Circumscribed mass


  • Cut surface is pink to tan and dark red


Size



  • Range: 0.5-6 cm


MICROSCOPIC PATHOLOGY


Histologic Features



  • Nests of tumor cells in highly vascular fibrous tissue


  • Chief cells have eosinophilic, finely granular cytoplasm and central nuclei



    • Nuclear pleomorphism may be present but is prognostically unimportant


  • Clear cells change focally or diffusely




  • Sustentacular cells at periphery of nests



    • Modified Schwann cells


  • Rare mitoses


  • Sinusoidal vascular pattern


  • Malignant features include



    • Marked nuclear pleomorphism, mitotic activity


    • Necrosis, vascular invasion


    • Paucity of sustentacular cells


    • Occurrence of metastasis


  • Hyalinizing variant

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Paraganglioma
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