Case Studies in Infrahyoid Neck

Nicholas A. Koontz, M.D.Neuroradiology Fellow, University of Utah

Financial Disclosures

But first…

• Please direct your smart phone, tablet, or laptop’s browser to:

Objectives

• Review Infrahyoid Neck Anatomy– Deep Spaces– Nodal Stations

• Cases, Cases, Cases– Tackle challenging cases– Develop an appropriate differential diagnosis– Identify useful discriminators

• Multiple choice questions

Anatomy

Anatomic Spaces of Infrahyoid Neck

Posterior Cervical Space

Visceral Space

Retropharyngeal Space

PerivertebralSpace

CarotidSpace

Infrahyoid Lymph Node Stations

Cases

Case 1

• 65 year-old woman with neck pain, palpable lump

Differential Diagnosis

• Differentiated Thyroid Ca

• Medullary Thyroid Ca

• Anaplastic Thyroid Ca

• Thyroid NHL

• Multinodular Goiter

Most Likely Diagnosis

• Differentiated Thyroid Ca (DTCa)• Age & Sex• Ill-defined• Infiltrating, invasive• Mixed solid/cystic• Intra-thyroidal• Calcs

• Intra-thyroidal• Intra-nodal

• Adenopathy• Some solid• Some cystic• Punctate calcs

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

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

DTCa Companion Cases

1) 75 year-old-woman, neck lump

2) 48 year-old-woman, enlarging mass

3) Nodal Manifestations of DTCa

4) 30 year-old-woman, adenoma

Magnified Cor CECT of LN

Case 2

• 55 year-old-woman with right neck mass, cough

Differential Diagnosis

• H&N SCCa Metastatic Nodes

• Systemic Nodal Metastases

• Thyroid Ca Metastatic Nodes

• HL or NHL Nodes

• Granulomatous Lymph Nodes

• Reactive Adenopathy

Most LikelyDiagnosis

• Systemic Nodal Mets• 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

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

-- Rick Wiggins

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

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

Companion Case

25-year-old man with neck mass

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

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

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

Case 4

• 55-year-old woman with known thyroid nodules, reportedly benign – surveillance US

Longitudinal Transverse

Power Doppler

Prior biopsy reported benign

Differential Diagnosis

• Congenital lesion• Lymphatic malformation• Venolymphatic malformation• Venous malformation• 3rd Branchial cleft cyst

• Neurofibroma

• Schwannoma

• Malignant Lymph node

• Carotid artery Pseudoaneurysm

Most LikelyDiagnosis

• Congenital lesion• 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?

Carotid Space Nerve Sheath Tumor

Pros• Location• Size• Morphology• Low Density

Cons• Echogenicity• Lack of vascularity

Image c/o Lauren Ladd, M.D.

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"

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

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

Case 5

• 25-year-old man with enlarging neck mass, recent URI

Same patient, 3 days prior

Differential Diagnosis

• Thyroglossal Duct Cyst

• Lymphatic Malformation

• Mixed Laryngocele

• Necrotic Lymph Node

• Abscess

• Thyroid Ca

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

Thyroglossal Duct CystKey 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

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

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

TGD Cyst Companion Cases

1) 50-year-old man with neck mass

TGD Cyst. High density = heme, protein.

2) Young girl, dysphagia

TGD Cyst. Suprahyoid/BOT.

3) Enlarging neck mass

TGD Cyst Thyroid Ca. Enhancing nodule. Coarse calc. Nodal Met.

4) Ectopic Thyroid

Case 6

• 31-year-old woman with difficult intubation during elective surgery

“I’ll tell you right now – that ain’t normal.”

-- Rick Wiggins

Ax T1WI +C FS Ax T1WI +C FS

Cor T1WI +C FS

Ax T2WI FS Ax T2WI FS

Differential Diagnosis

• NF1

• NF2

• Schwannomatosis

• Laryngeal SCCa with Mets

• Chondrosarcoma with Mets

Ax T1WI +C FSAx T2WI FS

Most Likely Diagnosis

• Schwannomatosis• 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

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

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

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)

Infrahyoid Neck Conclusion

• Several deep spaces & nodal stations– Wide variety of pathology

• Look for useful discriminators:– Age– History– Deep space of origin

Thanks

nick.koontz@hsc.utah.edu