Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings

Nicholas L. Deep, Joseph M. Hoxworth, Christopher J. Stevens, Michael J. Link, Colin L W Driscoll, Christopher P. Wood

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Objective: The radiologic appearance of arachnoid granulations (AGs) in typical locations is well established and they are rarely mistaken for other pathologies. However, when large and seen in atypical locations, such as along the posterior petrous bone, AGs can be a source of diagnostic and therapeutic confusion. We present two cases of giant posterior temporal bone AGs and review their clinical presentation, potential complications, and an imaging-based differential diagnosis. Patients: Two patients with surgically or pathologically proven giant symptomatic AGs in the posterior petrous bone. Main Outcome Measure: Clinical presentation, radiological features, surgical findings, and potential complications of giant AGs. Results: In two middle-aged women (37 and 55 years), computed tomography (CT) demonstrated solitary large lytic lesions in the posterior right petrous temporal bone. These were similar in appearance to cerebrospinal fluid (CSF) on magnetic resonance imaging (MRI), though they exhibited some minor deviations such as thin internal septations, mild peripheral enhancement, and heterogeneous signal on fluid-attenuated inversion recovery (FLAIR). The MRI appearance effectively distinguished the giant AGs from other lesions that can occur in this area such as endolymphatic sac tumor (ELST). Surgery was successfully performed to prevent complications from a CSF leak. Conclusion: The posterior temporal bone is an atypical location for AGs and can lead to diagnostic confusion, particularly when they are large. Familiarity with the characteristic imaging appearance of giant AGs in this location can help avoid misinterpretation as a more aggressive pathology and help recognize patients who are at risk for a CSF leak.

Original languageEnglish (US)
Pages (from-to)963-966
Number of pages4
JournalOtology and Neurotology
Volume37
Issue number7
DOIs
StatePublished - Aug 1 2016

Fingerprint

Arachnoid
Temporal Bone
Tomography
Magnetic Resonance Imaging
Petrous Bone
Confusion
Endolymphatic Sac
Pathology
Cerebrospinal Fluid
Differential Diagnosis
Outcome Assessment (Health Care)

Keywords

  • Arachnoid granulations
  • Endolymphatic sac tumor
  • Temporal bone imaging

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Sensory Systems
  • Clinical Neurology

Cite this

Deep, N. L., Hoxworth, J. M., Stevens, C. J., Link, M. J., Driscoll, C. L. W., & Wood, C. P. (2016). Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings. Otology and Neurotology, 37(7), 963-966. https://doi.org/10.1097/MAO.0000000000001109

Giant Posterior Temporal Bone Arachnoid Granulations : CT and MRI Findings. / Deep, Nicholas L.; Hoxworth, Joseph M.; Stevens, Christopher J.; Link, Michael J.; Driscoll, Colin L W; Wood, Christopher P.

In: Otology and Neurotology, Vol. 37, No. 7, 01.08.2016, p. 963-966.

Research output: Contribution to journalArticle

Deep, NL, Hoxworth, JM, Stevens, CJ, Link, MJ, Driscoll, CLW & Wood, CP 2016, 'Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings', Otology and Neurotology, vol. 37, no. 7, pp. 963-966. https://doi.org/10.1097/MAO.0000000000001109
Deep NL, Hoxworth JM, Stevens CJ, Link MJ, Driscoll CLW, Wood CP. Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings. Otology and Neurotology. 2016 Aug 1;37(7):963-966. https://doi.org/10.1097/MAO.0000000000001109
Deep, Nicholas L. ; Hoxworth, Joseph M. ; Stevens, Christopher J. ; Link, Michael J. ; Driscoll, Colin L W ; Wood, Christopher P. / Giant Posterior Temporal Bone Arachnoid Granulations : CT and MRI Findings. In: Otology and Neurotology. 2016 ; Vol. 37, No. 7. pp. 963-966.
@article{85fd77a220684dc9810e3fcd7da91bb7,
title = "Giant Posterior Temporal Bone Arachnoid Granulations: CT and MRI Findings",
abstract = "Objective: The radiologic appearance of arachnoid granulations (AGs) in typical locations is well established and they are rarely mistaken for other pathologies. However, when large and seen in atypical locations, such as along the posterior petrous bone, AGs can be a source of diagnostic and therapeutic confusion. We present two cases of giant posterior temporal bone AGs and review their clinical presentation, potential complications, and an imaging-based differential diagnosis. Patients: Two patients with surgically or pathologically proven giant symptomatic AGs in the posterior petrous bone. Main Outcome Measure: Clinical presentation, radiological features, surgical findings, and potential complications of giant AGs. Results: In two middle-aged women (37 and 55 years), computed tomography (CT) demonstrated solitary large lytic lesions in the posterior right petrous temporal bone. These were similar in appearance to cerebrospinal fluid (CSF) on magnetic resonance imaging (MRI), though they exhibited some minor deviations such as thin internal septations, mild peripheral enhancement, and heterogeneous signal on fluid-attenuated inversion recovery (FLAIR). The MRI appearance effectively distinguished the giant AGs from other lesions that can occur in this area such as endolymphatic sac tumor (ELST). Surgery was successfully performed to prevent complications from a CSF leak. Conclusion: The posterior temporal bone is an atypical location for AGs and can lead to diagnostic confusion, particularly when they are large. Familiarity with the characteristic imaging appearance of giant AGs in this location can help avoid misinterpretation as a more aggressive pathology and help recognize patients who are at risk for a CSF leak.",
keywords = "Arachnoid granulations, Endolymphatic sac tumor, Temporal bone imaging",
author = "Deep, {Nicholas L.} and Hoxworth, {Joseph M.} and Stevens, {Christopher J.} and Link, {Michael J.} and Driscoll, {Colin L W} and Wood, {Christopher P.}",
year = "2016",
month = "8",
day = "1",
doi = "10.1097/MAO.0000000000001109",
language = "English (US)",
volume = "37",
pages = "963--966",
journal = "Otology and Neurotology",
issn = "1531-7129",
publisher = "Lippincott Williams and Wilkins",
number = "7",

}

TY - JOUR

T1 - Giant Posterior Temporal Bone Arachnoid Granulations

T2 - CT and MRI Findings

AU - Deep, Nicholas L.

AU - Hoxworth, Joseph M.

AU - Stevens, Christopher J.

AU - Link, Michael J.

AU - Driscoll, Colin L W

AU - Wood, Christopher P.

PY - 2016/8/1

Y1 - 2016/8/1

N2 - Objective: The radiologic appearance of arachnoid granulations (AGs) in typical locations is well established and they are rarely mistaken for other pathologies. However, when large and seen in atypical locations, such as along the posterior petrous bone, AGs can be a source of diagnostic and therapeutic confusion. We present two cases of giant posterior temporal bone AGs and review their clinical presentation, potential complications, and an imaging-based differential diagnosis. Patients: Two patients with surgically or pathologically proven giant symptomatic AGs in the posterior petrous bone. Main Outcome Measure: Clinical presentation, radiological features, surgical findings, and potential complications of giant AGs. Results: In two middle-aged women (37 and 55 years), computed tomography (CT) demonstrated solitary large lytic lesions in the posterior right petrous temporal bone. These were similar in appearance to cerebrospinal fluid (CSF) on magnetic resonance imaging (MRI), though they exhibited some minor deviations such as thin internal septations, mild peripheral enhancement, and heterogeneous signal on fluid-attenuated inversion recovery (FLAIR). The MRI appearance effectively distinguished the giant AGs from other lesions that can occur in this area such as endolymphatic sac tumor (ELST). Surgery was successfully performed to prevent complications from a CSF leak. Conclusion: The posterior temporal bone is an atypical location for AGs and can lead to diagnostic confusion, particularly when they are large. Familiarity with the characteristic imaging appearance of giant AGs in this location can help avoid misinterpretation as a more aggressive pathology and help recognize patients who are at risk for a CSF leak.

AB - Objective: The radiologic appearance of arachnoid granulations (AGs) in typical locations is well established and they are rarely mistaken for other pathologies. However, when large and seen in atypical locations, such as along the posterior petrous bone, AGs can be a source of diagnostic and therapeutic confusion. We present two cases of giant posterior temporal bone AGs and review their clinical presentation, potential complications, and an imaging-based differential diagnosis. Patients: Two patients with surgically or pathologically proven giant symptomatic AGs in the posterior petrous bone. Main Outcome Measure: Clinical presentation, radiological features, surgical findings, and potential complications of giant AGs. Results: In two middle-aged women (37 and 55 years), computed tomography (CT) demonstrated solitary large lytic lesions in the posterior right petrous temporal bone. These were similar in appearance to cerebrospinal fluid (CSF) on magnetic resonance imaging (MRI), though they exhibited some minor deviations such as thin internal septations, mild peripheral enhancement, and heterogeneous signal on fluid-attenuated inversion recovery (FLAIR). The MRI appearance effectively distinguished the giant AGs from other lesions that can occur in this area such as endolymphatic sac tumor (ELST). Surgery was successfully performed to prevent complications from a CSF leak. Conclusion: The posterior temporal bone is an atypical location for AGs and can lead to diagnostic confusion, particularly when they are large. Familiarity with the characteristic imaging appearance of giant AGs in this location can help avoid misinterpretation as a more aggressive pathology and help recognize patients who are at risk for a CSF leak.

KW - Arachnoid granulations

KW - Endolymphatic sac tumor

KW - Temporal bone imaging

UR - http://www.scopus.com/inward/record.url?scp=84974711178&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84974711178&partnerID=8YFLogxK

U2 - 10.1097/MAO.0000000000001109

DO - 10.1097/MAO.0000000000001109

M3 - Article

C2 - 27295446

AN - SCOPUS:84974711178

VL - 37

SP - 963

EP - 966

JO - Otology and Neurotology

JF - Otology and Neurotology

SN - 1531-7129

IS - 7

ER -