A case-based journey with focus on elements of differential diagnosis. Presented at the European Society of Neuroradiology (ESNR) annual meeting in Rotterdam 2018

1. A Case-Based Journey
felice.d’arco@gosh.nhs.uk
http://www.slideshare.net/bluetango84

2. Case 1: 4 y Male, Haemophilus Influenzae meningitis, Right severe profound hearing
loss
2016
3 T
Artefact?
Labyrinthitis ossificans !
2017

3. Typical appearances : 16 year old , bilateral hearing loss :
L.O.: bulge of the cochlear promontory produced by the basal turn of the
cochlea
Joshi et al 2012
DDX:
Labyrinthin
e aplasia in
LAMM
syndrome,
small otic
capsule, no
promontory
Ossifying stage: 11 year-old , bilateral hearing loss :

4. Mode of spread: Meningogenic vs Tympanogenic
labyrinthitis

5. Mode of spread: Meningogenic vs Tympanogenic
labyrinthitis

6. Male 24 yo, nonulcerative keratitis, audiovestibular symptoms
and aortic aneurysm
Cogan Syndrome
- Prototypical autoimmune inner ear disorder
- Young adults
- Interstitial Keratitis
- Aortitis with arotic insufficency is a possible association
Casselman et al AJNR 1994

7. Labyrinthitis: Learning Points
 Acute/Subacute: CT normal, possible
faint enhancement on MRI, often
negative
Pearl: labyrinthine and VII enhancement + EAC vescicles: think of herpes zoster
(Ramsay Hunt syndrome)
 Chronic: fibrous stage, CT normal MR T2 CISS;
ossifying stage: CT and MRI
 Spread: tympanogenic, meningogenic,
hematogenic, post-traumatic.
 Viral +++, autoimmune (e.g.: Cogan),
S.Aureus, H. Influenzae, Pneumococcus.
 Be aware of intermediate stages

8. Asymmetric fatty Marrow
(leave me alone lesion)
Petrous
Apicitis

9. T2 T1 gad
Effusion of petrous apex air cells (leave me alone lesion)
T1
T2 T1
Cholesterol granuloma
(follow up!)
Courtesy Dr. L Pinelli

10. 6 y old with LP suggestive of bacterial meningitis
Petrous apex abscess

11. Petrous Apex Lesions: Learning Points
Pearl: Cholesterol granuloma DDX: Cholesteatoma: DWI restriction and low T1
signal
 Complex relationship with important structures;
cavernous sinus, Dorello canal and Meckel cave.
Chapman et al. AJR 2011
 Leave me alone lesions: effusion, “cephalocele”,
asymmetric fat.
 Cholesterol granuloma: bony erosion, hyper T1
and T2, peripheral hypo rim on T2. No DWI.
 Petrous Apicitis : sign of infections in the middle
ear and surrounding tissues: look for complication

12. Female 7 yo, genetic diagnosis of “3MC syndrome”, right ear cholesteatoma on
examination. Bilateral mixed hearing loss CT for petrous bone assessment
3 MC syndrome:
MASP1 gene
mutation,
developmental
delay and kidney,
heart, and eye
disease, hearing
loss,
craniosynostosis
Teaching point from this case:
- Soft tissue in the Prussak’s space +
Erosion + DWI restriction:
Cholesteatoma
- Non-epi DWI in Coronal
- Look beyond the middle ear
Talenti G; Pinelli
L, D’Arco, F.
Otology &
Neurotology.
2018.

13. Pars Flaccida Cholesteatoma: retraction theory
Decreased intratympanic pressure
Som P, Curtin H
Elsevier 2011;
Harnsberger R et
al. Elsevier 2016
T1 gad FST2
DWI HASTE
-Erosion
-T2
hyperintense
-T1 hypo and no
enhancement !
-DWI restriction
(spin echo/ FSE
multishot)
De Foer et al 2006/Lehmann et al 2009; case courtesy: Dr A.

14. Pars flaccida Cholesteatoma: differential diagnosis
1)Pars Tensa Cholesteatoma: Location!
2) Granulation Tissue: No erosion but intense
enhancement (common!)
3) Middle ear Cholesterol Granuloma
 Posterior tympanic recesses (facial and tympanic).
 Displacement ossicles antero-laterally
 Opposite of PF Cholesteatoma
 Otoscopy
Som P, Curtin H Elsevier
2011;
 Recurrent hemorrhage in inflamed middle ear
 High signal in both T1 and T2
 “blue” eardrum
 May or may not destroy the bone (CT less useful)
 Peripheral rim in T2 due to haemorrhages

15. 4) Postinflammatory ossicular erosion (non-
cholesteatomatous ossicular erosion)
Pars flaccida Cholesteatoma: differential diagnosis
2 parallel line:
ANT: malleulus neck &
T. Tympani tendon
POST: incus lenticular
proc. & ISJ
Absence of
posterior “line”
Ossicular “right angle:
Vertical incus long
process
Horizonal lenticular
process
Right angle is
missing!
“Clean” TM !

16. Middle ear: differential diagnosis
5) Don’t forget the uncommon / unexpected: use clinical context
6 yo boy
Langerhans cell histiocytosis (LCH)
11 yo boy, beta-thalassemia
major
Extramedullary Hematopoiesis
Courtesy of Dr. A. Taranath

17. Female 14 m, genetic diagnosis of “KID syndrome”, hearing loss, preterm, difficult to
test ABR, dry and thickened skin, absent eye lashes
Keratitis-ichthyosis-
deafness (KID)
syndrome: GJB2
gene mutation, eye
problems, skin
abnormalities, and
hearing loss.
Teaching point from this case:
- Don’t forget the clinical context
- No erosion in keratosis
Obturans!
- Abutting tympanic membrane
- KID: look at the cerebellum
(Usu et al. 1988)
EAC cholesteatoma?EAC blocked by flaky skin in context
of KID (Keratosis Obturans)

18. Inflammation EAC: Keratosis Obturans and differential
diagnoses
Diagnostic Imaging: Head and Neck, 3rd Edition. Harnsberg 2016; Dr. L Pinelli
1) Keratosis Obturans
 Accumulation & obstruction of bony EAC from
desquamated keratin without erosive bony
changes
 Benign soft tissue in EAC
 enlargement +; erosion -.
 Conductive HL
Pearls: Internal bony
flecks, DWI + , initial
submucosal mass
2) EAC cholesteatoma
 Scalloping/erosion EAC, extensions other
bones
 Bony fragments within the mass (50%)
 Middle ear spared (same as KO)
 Can be postoperative/posttraumatic or congenital
(small EAC)

19. Inflammation EAC: Keratosis Obturans and differential
diagnoses
Diagnostic Imaging: Head and Neck, 3rd Edition. Harnsberg 2016; Som & Curtin 2011
3) Necrotizing External Otitis
 Severe infection of EAC
(P.Aeruginosa + Diabetes)
 Swollen EAC with erosion, cellulitits or
abscess
 Best imaging: T2 STIR/T1 C+ FS
 Clinical context
4) Tumours
SCC: elderly, biopsy (identical to other Dx on
imaging) , look for perineural/nodal spread RMS: Children, large mass
4 day old infantile sarcoma NOS
Courtesy Dr. L Pinelli

20.  DDX with mimics can be challenging
 Look for presence (or not) of erosion on CT
 Do not forget clinical context
 Look for associated abnormalities (syndromic association,
malformations, extension in other parts of the skull base)
 MRI and CT are complementary
Conclusion

21. Thank you
Inflatable MRI scanner
Acknowledgements
- Dr. Lorenzo Pinelli, Brescia University Hospital, Brescia - Italy
- Dr. Ajay Taranath, Women's and Children's Hospital, North Adelaide, Australia.
- Dr. Lorenzo Ugga, University Hospital “Federico II”, Naples – Italy
- Prof. Sotirios Bisdas, UCLH, London – UK
- Pediatric Neuroradiology Unit, Great Ormond Street Hospital, London – UK:
Drs. O. Carney, U. Lobel, K. Mankad and S. Sudhakar