Cerebrospinal Fluid Rhinorrhea and a Lytic-Appearing Lesion | Otolaryngology | JN Learning | AMA Ed Hub [Skip to Content]
[Skip to Content Landing]

Cerebrospinal Fluid Rhinorrhea and a Lytic-Appearing Lesion of the Posterior Cranial Fossa

Educational Objective
Based on this clinical scenario and the accompanying image, understand how to arrive at a correct diagnosis.
1 Credit CME

A man in his 60s presented to the otolaryngology clinic with a 1-month history of clear drainage from his left naris during activity. Approximately 1 month prior he had been admitted to the hospital and treated for meningitis. During his hospital course, a computed tomographic (CT) scan of his head revealed a lytic lesion of the left occipital bone. After treatment with intravenous antibiotics and steroids, his neurologic examination results returned to baseline, and he was discharged home. Magnetic resonance imaging (MRI) was deferred to the outpatient setting. At the otolaryngologist’s office, the patient stated that he had not experienced otalgia, otorrhea, tinnitus, or vertigo. His examination revealed clear nasal discharge and a normal otoscopic finding. His audiogram demonstrated normal sloping to moderate sensorineural hearing loss with type A tympanometry result on the right and type A on the left. His word recognition score was 100% bilaterally. The collection of nasal discharge for β-2 transferrin analysis was attempted, but insufficient quantity was obtained. To evaluate for a skull base defect and cerebrospinal fluid (CSF) leak, a noncontrast CT scan of the temporal bones was obtained (Figure, A and B). This demonstrated a large area of bony destruction and osteolysis involving the left occipital bone. A T2-weighted MRI sequence showed a lesion, isointense to CSF, with thinning of the bony cortex (Figure, C and D). Based on the imaging, the differential diagnosis included metabolic, infectious, or metastatic lesions to the bone.

Please finish quiz first before checking answer.

You answered correctly!

Read the answer below and download your certificate.

You answered incorrectly.

Read the discussion below and retake the quiz.

C. Intradiploic meningoencephalocele

The intradiploic space is a marrow-filled space between the inner and outer cortices of the calvarium. Intradiploic meningoencephaloceles are uncommon and represent a small percentage of meningoencephaloceles. The etiology of these lesions is often unidentified; however, they are thought to be congenital, posttraumatic, or iatrogenic.1,2 They are often found incidentally during the workup of acute neurologic symptoms, and presentation is highly variable depending on the site of the lesion. The mechanism through which these lesions are thought to occur is through traumatic violation of the inner cortical table followed by negative pressure causing herniation of the underlying brain tissue.2,3 Most patients present with stroke-like symptoms because the most common location is the parietal aspect of the skull.3 This case is interesting in that the patient did not report a history of trauma or identifiable etiologies, and he presented with Streptococcus pneumonia meningitis complicated by CSF rhinorrhea. This presentation is likely caused by CSF within the diploic space that egressed through the mastoid air cells into the middle ear cavity, subsequently traveling via the eustachian tube to the nasopharynx and resulting in rhinorrhea.

Survey Complete!

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

Article Information

Corresponding Author: Kinneri Mehta, MD, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030 (kmehta@uchc.edu).

Published Online: December 14, 2017. doi:10.1001/jamaoto.2017.2440

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported.

References
1.
Martínez-Lage  JF, López  F, Piqueras  C, Poza  M.  Iatrogenic intradiploic meningoencephalocele: case report.  J Neurosurg. 1997;87(3):468-471.PubMedGoogle ScholarCrossref
2.
Patil  AA, Etemadrezaie  H.  Posttraumatic intradiploic meningoencephalocele: case report.  J Neurosurg. 1996;84(2):284-287.PubMedGoogle ScholarCrossref
3.
Arevalo-Perez  J, Millán-Juncos  JM.  Parietal intradiploic encephalocele: report of a case and review of the literature.  Neuroradiol J. 2015;28(3):264-267.PubMedGoogle ScholarCrossref
4.
Peters  J, Raab  P, Marquardt  G, Zanella  FE.  Intradiploic meningoencephalocele.  Eur Radiol. 2002;12(suppl 3):S25-S27.PubMedGoogle ScholarCrossref
5.
Stone  JA, Castillo  M, Neelon  B, Mukherji  SK.  Evaluation of CSF leaks: high-resolution CT compared with contrast-enhanced CT and radionuclide cisternography.  AJNR Am J Neuroradiol. 1999;20(4):706-712.PubMedGoogle Scholar
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
Close
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
Close
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Close

Name Your Search

Save Search
Close
With a personal account, you can:
  • Track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
jn-learning_Modal_SaveSearch_NoAccess_Purchase
Close

Lookup An Activity

or

Close

My Saved Searches

You currently have no searches saved.

Close
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Close