Presented at the European Course of Pediatric Neuroradiology - ECPNR 2020 in Rome

1. A Practical Guide to the
Differential Diagnosis
felice.d’arco@gosh.nhs.uk
https://www.slideshare.net/bluetango84/presentations

2.  Case-based presentation
 Case  teaching points  radiological
differential diagnoses
 Warm-up case
 Solid masses H&N
 Cystic masses H&N
 Temporal bone
 Total 22 cases!
Structure of this Workshop
That’s about 2
minutes/case
!!

3. Q: what we do next?
WARM-UP CASE: 6 month-old lump on the vault
Metastatic Neuroblastoma  US
abdomen!

4.  Metastatic : Typical Osseous Meta in Calvarium,
Skull base, Orbits, Temporal bones  ↑ DWI ↓ ADC,
c.e.
 Radiologist need to suggest abdominal US
 MIBG uptake
 Rare Nodal Metastasis
Neuroblastoma

5.  Primary Neck NB : Posterior and
Carotid Spaces
 1-5 % of NB
 Moderately enhancing mass
 Associated Lymphoadenopathy
 DD with Reactive Nodes and
Lymphoma very difficult (biopsy)
 Presence of Ca++ (extremely rare in
Lymphoma)
Neuroblastoma

6. Solid Neck Masses

7. 1) Well-defined enhancing
mass
2) ↓ DWI, ↑ ADC
3) Internal flow voids
1 year old baby girl

8.  IMAGING Key Features:
 Well-defined enhancing mass, mildly hyper T2 to muscle
 Internal Vessels (Serpiginous Flow Voids)
 No Calcifications! (DD Venous Malformation)
 US: mean venous peaks not elevated (DD AVM)
 Involuting Phase: fatty replacement
Infantile Hemangioma

9. First
Diagnosi
s
After
Treatment
with
Propanolol
Companion Case

10. Differential Diagnosis
Phleboliths: Calcium within the lesion

11. Differential Diagnosis
1) Venous Malformation
Large venous lakes
- T2 signal more hyperintense
- Variable enhancement (patchy,
heterogeneous)
- Phleboliths: Calcium within the
lesion
- No Flow voids

12. Differential Diagnosis

13. Auricular
artery
Maxillary artery
RASA1 mutation (CM-AVM syndrome)

14. Differential Diagnosis
2) AVM
- High flow and tortuous
feeding arteries
- Nidus/AV shunting
- US: elevated venous peaks
- Worsening overtime
- Clinical: arterial feeding is
evident

15. Companion Case
Dieng et al 2015

17. Differential Diagnosis
3) Rhabdomyosarcoma
- Different age : 2- 5 y; 15-19 y
- Aggressive behavior: bony erosion,
invasions surrounding tissues
- Non-Homogeneous appearance
(necrosis, hemorrhage) and contrast
- ↑ DWI ↓ ADC (Lope 2012)
- Avid FDG

18. Cystic Neck Masses

19. Q: Where is it? How it looks like?

21.  Remnant of the TGD (Between foramen
cecum at tongue base → thyroid bed in
infrahyoid neck)
 Most common congenital neck
lesions
 Median cyst (could be also
paramedian in the infrahyoid neck)
 Thin rim of c.e. is possible (often
associated with infection)
 Embedded by strap muscles when
infrahyoid (“claw sign”)
Thyroglossal Duct Cyst
Harnsberger 2004

22. Differential Diagnosis
1) Median Sub-Lingual
Abscess
- Clinical: associated
Odontogenic or salivary
gland infection
- Thick enhancing wall, DWI
restriction in MRI
Harnsberger 2004

23. NB: most frequent location of an abscess in neck
is retropharyngeal space

24. 1st branchial cleft anomaly (cyst)
Q: what’s that?

25.  Congenital malformations during development of the
branchial apparatus
 4 types of branchial cleft anomalies: cysts, sinuses,
fistulas from the 1st , 2nd, 3rd and 4th branchial arches
 2nd branchial cleft anomaly is the most common:
95%
Branchial Cleft Anomalies
Head and neck region
at 4 weeks gestation
(Meuwly et al 2005)

26. 1st Branchial Cleft
Anomaly
 Benign, congenital cyst in or adjacent to parotid
gland, EAC, or pinna
 Several classifications related to embryology or
location
Postero-inferior to auricle Adjacent to parotid gl./mandible angle
B. Koch 2015

28. Clue for the diagnosis: what are the 3 anatomical bounders of this lesion?

29. Q: what what’s the difference from the previous?

30. 2nd Branchial Cleft
Anomaly
 Typical location: Antero-medially to the SCM
(superior 1/3), posteriorly to the submandibular
gland, laterally to the carotid space
B. Koch 2015

31. 3rd Branchial Cleft Anomaly
-Medially to the middle 1/3 of the SCM
-Lower than 2nd BCC
-In the posterior cervical space
B. Koch 2015
Carotid sp
3BCC
SCM
Post Cerv
Sp

32. Pt.1 : 21 day-old
Thyroid
Pt.2
4th Branchial Cleft Anomaly
It is a tract from the pyriform sinus to
the
Superior aspect of the thyroid
Q: what are the arrows indicating?

33. Q: what’s the difference?

34.  Uni- or multiloculated, non-enhancing, cystic neck
mass.
 Micro- and macro cystic
 Often trans-spatial, with fluid-fluid levels
(hemorrhage and high proteinaceous components)
 Venolymphatic Malf. : Combined elements of venous
malformation & lymphatic malformation (contrast
enhancement of the venous elements)
Lymphatic Malformation

35. Fluid-fluid levels: Diagnosis?
Aneurysmal Bone Cyst

36. Q: Diagnosis?

37. Dermoid/Epidermoid Cyst
 Definition: Cystic mass resulting from congenital
epithelial inclusion or rest
 Epidermoid: Epithelial elements only, fluid content
 Dermoid: Epithelial elements plus dermal
substructure, fluid, fatty or mixed content
 Location: oral cavity (DD with Ranula and TGDC),
midline anterior neck (DD with TGDC), orbit (DD
with abscess and lymphatic malf.), nasal with
associated nasal dermal sinus ± intracranial
extension

38. Imaging
Epidermoid: homogeneous T1
hypo and T2 hyper. Increase T1
signal if high protein fluid
Dermoid: heterogeneous
signal. Fatty elements are T1
hyper and low in fat sat T2.
Possible Ca++
Both can have DWI restriction
and thin rim enhancement
T1 T2 fat-sat
T1
Pearl: in your report use dermoid/epidermoid
cyst

39. Mixed solido-cystic mass with fat content

40. Pearl: look for T1 hyperintensity of the fat!
Q: How would you described this ?

42. Teratoma
 Anterior neck, midline mass containing all 3 germ
layers
 Mixed (cystic and solid) with fat and calcium
 DD: Lymphatic Malf (fluid with no fat, calcium or
solid components), Goiter (homogeneous, respects
limits of the thyroid gland)

43. 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.

44. 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.

45. 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 !

46. Final case
10-week-old girl with
right orbital swelling
coronal T2WI STIR

47. IMAGING
Axial STIR
Cor STIR ADC
Cor STIR

48. IMAGING
Sagittal T1WI + Gado
Axial T2WI ADC
AxialT1WI + Gado

49. What is the best diagnosis?
A. Metastatic neuroblastoma
B. Rhabdomyosarcoma with brain and nodal
metastasis
C. SMARCB1 mutation
D. Atypical tuberculosis
QUESTION

50. What is the best diagnosis?
A. Metastatic neuroblastoma
B. Rhabdomyosarcoma with brain and nodal
metastasis
C. SMARCB1 mutation (ATRT with synchronous orbital
rhabdoid tumor )
D. Atypical tuberculosis
QUESTION

51. • ATRT is an embryonal tumor, shows very low ADC values
(same as Medulloblastoma and ETMR) with or without
enhancement
• Rhabdoid tumors may occur synchronously in 2 or more
locations, typically due to the patient carrying a germline
SMARCB1 alteration
• Pearl: brain tumor in child with strong diffusion restriction:
think of embryonal tumour. ATRT and ETMR typically <3y
DISCUSSION

52. Thank you
Capri – Italy