1. Case Studies in Infrahyoid Neck
Nicholas A. Koontz, M.D.
Neuroradiology Fellow, University of Utah

2. Financial Disclosures

3. But first…
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4. Objectives Review Infrahyoid Neck Anatomy Cases, Cases, Cases
Deep Spaces
Nodal Stations
Cases, Cases, Cases
Tackle challenging cases
Develop an appropriate differential diagnosis
Identify useful discriminators
Multiple choice questions

5. Anatomy

6. Anatomic Spaces of Infrahyoid Neck
Visceral Space
Carotid
Space
Retropharyngeal
Space
Perivertebral
Space
Posterior
Cervical Space

7. Infrahyoid Lymph Node Stations

8. Cases

9. Case 1
65 year-old woman with neck pain, palpable lump

10. Red Arrow = Enlarged, heterogeneous attenuation/enhancing thyroid mass with internal calcs
Yellow Arrow = Indistinct & infiltrating margins, effacement of IJV
Green Arrow = Cystic level III met

11. Red Arrow = Intrathyroidal calcs

12. Red Arrow = Punctate calc associated with necrotic level III node
Orange Arrows = Additional solid adenopathy

13. Differential Diagnosis
Differentiated Thyroid Ca
Medullary Thyroid Ca
Anaplastic Thyroid Ca
Thyroid NHL
Multinodular Goiter

14. Most Likely Diagnosis Differentiated Thyroid Ca (DTCa) Age & Sex
Ill-defined
Infiltrating, invasive
Mixed solid/cystic
Intra-thyroidal
Calcs
Intra-nodal
Adenopathy
Some solid
Some cystic
Punctate calcs

16. Question 1 Which of the following is a TRUE statement?
A. Follicular is the most common subtype of DTCa
B. Hematogenous spread is more commonly associated with Papillary carcinoma
C. The peak incidence of DTCa is seen in women in the third or fourth decade
D. Rising free T4 is a clinical marker for disease recurrence

17. Question 1 Which of the following is a TRUE statement?
A. Follicular is the most common subtype of DTCa
B. Hematogenous spread is more commonly associated with Papillary carcinoma
C. The peak incidence of DTCa is seen in women in the third or fourth decade
D. Rising free T4 is a clinical marker for disease recurrence
Papillary = 80%, Follicular = 10%
Papillary  nodal, follicular  hematogenous
3x more common in women, peak incidence in 20s to 30s
Thyroglobulin = clinical marker of recurrence

18. DTCa Companion Cases

19. 1) 75 year-old-woman, neck lump
Yellow Arrow = Heterogeneous thyroid mass
Red Arrows = Punctate calcs within thyroid mass and enlarged superior mediastinal node

20. 2) 48 year-old-woman, enlarging mass
Red Arrow = Heterogeneous thyroid mass with punctate & stippled calcs
Green Arrows = Heterogeneously enhancing/cystic adenopathy

21. 3) Nodal Manifestations of DTCa
Green Arrow = Cystic, necrotic adenopathy
Red Arrow = Punctate calc in LN
Blue Arrow = High T1 SI node (thyroglobulin)
Yellow Arrow = Low T1 SI node

22. 4) 30 year-old-woman, adenoma
Yellow Arrow = Circumscribed, heterogeneous attenuation/enhancment thyroid mass
Red Arrow = Effaced subglottic & tracheal airway
Blue Arrow = Prominent solid jugulodigastric node, maintained reniform shape. No calcs or necrosis.
Magnified Cor CECT of LN

23. Case 2
55 year-old-woman with right neck mass, cough

24. Yellow Arrows = Heterogeneous attenuation LNs

25. Differential Diagnosis
H&N SCCa Metastatic Nodes
Systemic Nodal Metastases
Thyroid Ca Metastatic Nodes
HL or NHL Nodes
Granulomatous Lymph Nodes
Reactive Adenopathy

26. Most Likely Diagnosis Systemic Nodal Mets Central low-density/necrosis
Infrahyoid (level IV) location
H&N primary SCCa more commonly levels II & III
Non-calcified
Sarcoid, DTCa often Ca++
Central low-density/necrosis
HL, NHL, & reactive nodes usually solid, but can be low-density

27. Use Everything at Your Disposal
“I’ll tell you right now – that ain’t normal.”
-- Rick Wiggins

30. Question 2
Which of the following is MOST suggestive of systemic nodal metastases in the neck?
A. Enlarged suprahyoid (level I or II) node
B. Enlarged left supraclavicular lymph node
C. Centrally necrotic lymph node
D. Calcification within an enlarged cervical node

31. Question 2
Which of the following is MOST suggestive of systemic nodal metastases in the neck?
A. Enlarged suprahyoid (level I or II) node
B. Enlarged left supraclavicular lymph node
C. Centrally necrotic lymph node
D. Calcification within an enlarged cervical node
Systemic nodal mets infrahyoid > suprahyoid
“Signal” node.
Central necrosis nonspecific, can be from H&N SCCa, systemic mets, suppurative nodes, etc.
Calcs may be seen in DTCa, adenoCa mets.

32. Companion Case

33. 25-year-old man with neck mass
Yellow Arrows = Heterogeneous low attenuation supraclavicular LNs and axial adenopathy

34. HL with “Signal” Node AKA Virchow node
Isolated left supraclavicular adenopathy  look to the chest & abdomen for primary
Most HL patients present with neck nodes
Concurrent mediastinal nodes common
Rarely extranodal H&N disease
M > F
Peak incidence in mid-20s

36. Question 3 Which of the following is a TRUE statement?
A. HL is more common than NHL
B. Extranodal disease favors HL over NHL
C. Imaging can reliably differentiate NHL from HL
D. HL has an earlier peak incidence than NHL

37. Question 3 Which of the following is a TRUE statement?
A. HL is more common than NHL
B. Extranodal disease favors HL over NHL
C. Imaging can reliably differentiate NHL from HL
D. HL has an earlier peak incidence than NHL
NHL is more common than HL (HL = 14% of lymphoma)
HL is RARELY extranodal (<1%), NHL extranodal in 30%
Imaging is good for staging disease, but poor at differentiating HL from NHL
HL median age = 27, NHL median age = 53

38. Case 4
55-year-old woman with known thyroid nodules, reportedly benign – surveillance US

39. Longitudinal
Transverse
Power Doppler

40. Prior biopsy reported benign

41. Yellow Arrows = Low-density, poorly enhancing carotid space mass

42. Differential Diagnosis
Congenital lesion
Lymphatic malformation
Venolymphatic malformation
Venous malformation
3rd Branchial cleft cyst
Neurofibroma
Schwannoma
Malignant Lymph node
Carotid artery Pseudoaneurysm

43. Most Likely Diagnosis Congenital lesion Why not a NST?
Lymphatic malformation
Benign, circumscribed
No flow on US
Demonstrably separate from IJV and CCA
Venolymphatic malformation
Possible, but would have essentially no venous component
Why not a NST?

44. Carotid Space Nerve Sheath Tumor
Image c/o Lauren Ladd, M.D.
Pros
Cons
Location
Size
Morphology
Low Density
Echogenicity
Lack of vascularity

45. CS Nerve Sheath Tumor Comparison
CS Schwannoma
CS Neurofibroma
Shape
Fusiform
Ovoid or fusiform (***unless plexiform)
Margins
Circumscribed
Circumscribed (***unless plexiform)
Size
2 - 8 cm
2 - 5 cm
M:F
Male predominance
Female Predominance
NECT
Isodense to muscle
Hypodense
CECT
Uniform enhancement, rare low density
Poorly enhancing
T1WI -C
Variable, no flow voids
Isointense to muscle
T1WI +C
Marked uniform enhancement
Homogeneous or patchy enhancement
T2WI
Hyperintense to muscle, +/- intratumoral cysts
Very hyperintense, "target sign"

47. Question 4 Which of the following is a FALSE statement?
A. Most lymphatic malformations are diagnosed before age 2
B. Lymphatic malformations can be acquired
C. Lymphatic malformations have no malignant potential
D. Microcystic lymphatic malformations are less likely to recur than macrocystic malformations

48. Question 4 Which of the following is a FALSE statement?
A. Most lymphatic malformations are diagnosed before age 2
B. Lymphatic malformations can be acquired
C. Lymphatic malformations have no malignant potential
D. Microcystic lymphatic malformations are less likely to recur than macrocystic malformations
90% diagnosed by age 2
In adults lymphatic malformations can be acquired  think trauma.
No malignant potential.
LM can be micro or macro cystic – microcystic are more likely to recur than macrocystic.

49. Case 5
25-year-old man with enlarging neck mass, recent URI

50. Yellow Arrow = Thick walled, peripherally enhancing midline infrahyoid lesion just below hyoid
Red Arrow = Additional thick walled, peripherally enhancing midline lesion FOM

51. Yellow Arrow = same peripherally enhancing lesion in Cor
Cyan Arrow = corticated osseous defect in hyoid bone

52. Yellow Arrow = TGDC
Red Arrow = FOM abscess

53. Same patient, 3 days prior
Yellow Arrow = Same TGDC, smaller, less enhancement
Red Arrow = Blush of enhancement, no abscess

54. Differential Diagnosis
Thyroglossal Duct Cyst
Lymphatic Malformation
Mixed Laryngocele
Necrotic Lymph Node
Abscess
Thyroid Ca
Lymphatic malformation can look identical  history is your friend

55. Most Likely Diagnosis
Infected Thyroglossal Duct Cyst with associated FOM Abscess
Classic history
Midline/paramidline infrahyoid
Wall enhancement  infected
Round or ovoid
Cyst
No calcs or solid component

56. Thyroglossal Duct Cyst Key Points
Cystic remnant of TGD
Lesion of the young
Location
20-25% = Suprahyoid
50% = Hyoid
25% = Infrahyoid
Infrahyoid typically embedded in strap muscles  “claw” sign
Wall enhancement if infected
< 1% will develop Thyroid Ca

58. Question 5 Which of the following is a TRUE statement?
A. Thyroglossal duct cyst is the most common congenital neck mass
B. Thyroglossal duct cysts are always midline structures
C. The most common malignancy to develop in a thyroglossal duct cyst is medullary thyroid Ca
D. Treatment of thyroglossal duct cyst is typically needle aspiration

59. Question 5 Which of the following is a TRUE statement?
A. Thyroglossal duct cyst is the most common congenital neck mass
B. Thyroglossal duct cysts are always midline structures
C. The most common malignancy to develop in a thyroglossal duct cyst is medullary thyroid Ca
D. Treatment of thyroglossal duct cyst is typically needle aspiration
True.
Off-midline below the hyoid
Well-differentiated thyroid Ca, usually papillary
Sistrunk procedure (cyst, tract, and branch excision requiring removal of the central hyoid bone)

60. TGD Cyst Companion Cases

61. 1) 50-year-old man with neck mass
TGD Cyst. High density = heme, protein.

62. TGD Cyst. Suprahyoid/BOT.
2) Young girl, dysphagia
TGD Cyst. Suprahyoid/BOT.

63. TGD Cyst Thyroid Ca. Enhancing nodule. Coarse calc. Nodal Met.
3) Enlarging neck mass
TGD Cyst Thyroid Ca. Enhancing nodule. Coarse calc. Nodal Met.

64. 4) Ectopic Thyroid

65. Case 6
31-year-old woman with difficult intubation during elective surgery

66. Yellow Arrows = Circumscribed, heterogeneous submucosal mass originating in subglottic larynx. No deep invasion.

67. “I’ll tell you right now – that ain’t normal.”
-- Rick Wiggins
Green Arrow = Low density mass at skull bass, carotid space
Red Arrows = Similar density L infraclavicular masses

68. Ax T1WI +C FS Ax T1WI +C FS Cor T1WI +C FS Ax T2WI FS Ax T2WI FS
Yellow Arrows = Subglottic larynx mass
Red Arrows = Infraclavic masses
Green Arrows = CS mass
Cor T1WI +C FS
Ax T2WI FS
Ax T2WI FS

69. Differential Diagnosis
NF1
NF2
Schwannomatosis
Laryngeal SCCa with Mets
Chondrosarcoma with Mets
Intrinsic vs Extrinsic causes

71. Ax T2WI FS
Ax T1WI +C FS
Normal IACs

72. Most Likely Diagnosis Schwannomatosis No matrix calcification
Morphology & Margins
SCCa  infiltrative/invasive
Distribution
CS + Brachial plexus  NST
NORMAL IACs
NF2 less likely
Age
NF1 = 1st decade
NF2 = 2nd decade
Schwannomatosis = 3-4th decades
No matrix calcification
MR signal  NST
Intrinsic vs Extrinsic causes

74. Question 6 Which of the following is a TRUE statement?
A. Schwannomas grow centrally within an involved nerve
B. Schwannomatosis patients demonstrate a normal life expectancy
C. Schwannomas arise from pericytes in the nerve sheath
D. Schwannomatosis is more common than NF1

75. Question 6 Which of the following is a TRUE statement?
A. Schwannomas grow centrally within an involved nerve
B. Schwannomatosis patients demonstrate a normal life expectancy
C. Schwannomas arise from pericytes in the nerve sheath
D. Schwannomatosis is more common than NF1
Eccentric to affected nerve.
Normal life expectancy, unlike NF2
Arive from Schwann cells, not pericytes
NF1 > NF2 ~ Schwannomatosis

76. Schwannomatosis Key Points
Multiple nonintradermal schwannomas WITHOUT vestibular nerve involvement
Separate disease entity from NF2
Different gene mutation
SMARCB1 vs. NF2
Later onset
4th decade vs. 2nd decade
Normal life expectancy (unlike NF2)
Pain >> neurologic deficits (unlike NF2)
Similar incidence to NF2 (~ 1/40,000)

77. Infrahyoid Neck Conclusion
Several deep spaces & nodal stations
Wide variety of pathology
Look for useful discriminators:
Age
History
Deep space of origin

78. Thanks