Chemodectomas

Etiology

  • derived from neural crest tissue of the second branchial arch associated with either cranial nerve IX or X.
  • also called glomus tumors or paraganglioma
  • pheochromocytomas that develop in paraganglia other than adrenal medulla are designated paragagliomas

Pathology

  • Histologically benign tumors resembling the parent tissue
  • criterion of malignancy is based on clinical progression rather than histology

Clinical Presentation

  • lesions are rare before age of 20
  • originate anywhere glomus bodies are found

Routes of Spread

  • slow growing but can be problematic due to their location
  • low potential for metastatic disease

Diagnostic Studies

  • biopsy can lead serious hemorrhage due to their high vascularity

Treatment

Surgery

Site of Origin Surgery Comments
gloumus tympanicum approach through the eardrum conductive lose may be correctable
glomus jugulare • mastoidectomy or
• subtotal temoral bone resection
surgery is reserved for radiation failure
carotid body standard neck incision
  • LCR: local control rate
  • major risks of surgery include
    • hemorrhage
    • CN injury

Radiation

  • 45 Gy in 1.8 Gy/fraction to tumor volume

Chemotherapy

  • not sensitive to chemotherapy

Outcome

from Devita 7th, p 722; and Gunderson 2nd, p 556

Tumor location Local Control w/ Surgery Local Control w/ RT
temporal bone 89% to 95% at 5 years 91%
carotid body 89% at 7 years 97%
Bibliography
1. Cox J, Ang K. Radiation Oncology: rationale Technique Results. 8th ed. New York: Mosby, 2003.
2. Gunderson L, Tepper J: Clinical Radiation Oncology. 2nd ed. China: Elsevier 2007.
3. Devita V, Hellman S, Rsenberg S: Cancer: Principles and practice of Oncology. 7th ed. Philadelphia: Lippincott, 2005.
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