(tdc) and cystic neck masses

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Thyroglossal duct cyst (TDC) and

cystic neck masses Anna Calabrò, University of Trieste

School of Medicine

Gillian Lieberman, MD

April 2014 Anna Calabro’


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Agenda

Our patient’s history

Our patient’s imaging work up and findings

Neck anatomy

TDC Anatomy-Embryology-Epidemiology

TDC Radiographics features

Differential diagnosis of TDC

Other cystic neck masses

Anna Calabro’


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19 year old male

Patient presented with a 3 weeks history of

palpable mass in the region of the right

lateral thyroid cartilage

Otherwise healthy and asymptomatic

Anna Calabro’


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Menu of tests

Ultrasound

Doppler ultrasound

MR neck with and without gadolinium

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Our patient: neck mass on US

Elongated cystic anechoic structure PACS, MTAH

Anna Calabro’


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Our patient: neck mass on doppler US

Anechoic fluid collection without internal vascularity

PACS, MTAH

Anna Calabro’


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Our patient: neck mass on MR

Axial MRI neck,T2, fat saturation Coronal MRI neck, T2, fat saturation

PACS, MTAH

HYPERINTENSE lobulated cystic structure

hyoid bone level

insinuates in the right strap musculature

Anna Calabro’


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PACS, MTAH

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Our patient: neck mass on contrast MR

PACS, MTAH

Axial MRI neck, T1, fat saturation Coronal MRI neck, T1, fat saturation

HYPOINTENSE lobulated cystic structure

hyoid bone insinuating in the strap muscles

Rim enhancement!

Anna Calabro’


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PACS, MTAH

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Agenda



Neck anatomy





Anna Calabro’


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Neck anatomy

The neck can be divided into 2 regions:

- The posterior triangle, bordered by the SCM muscle, trapezius muscle and the clavicle.

- The anterior triangle, bordered by the SCM muscle and the mandible.

Drake:Gray’s Anatomy for students,2nd Edition

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https://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=brZX5EChehUC5M&tbnid=reJf3W1XCmmUAM:&ved=0CAUQjRw&url=https%25252525253A%25252525252F%25252525252Fweb.duke.edu%25252525252Fanatomy%25252525252FLab21%25252525252FLab21.html&ei=sStQU67NK7O0sQS-14DwDg&bvm=bv.64764171,d.aWw&psig=AFQjCNGyxI-IbX8x580LkN2cuJbvgZHOKw&ust=1397849354118368

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Neck anatomy

The anterior triangle is divided into the

SUPRAHYOID region

INFRAHYOID region

by the HYOID bone

Hyoid bone

Anna Calabro’


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www.radiologyassistant.nl

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Let’s review our patient’s lesion imaging

findings

Midline/para midline location

Hyoid bone level or below it

Insinuates strap muscles

Anechoic cystic structure on US

No internal vasculature on Doppler US

Hypointense on T1 sequence

Hyperintense on T2 sequence

Anna Calabro’


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Thyroglossal duct cyst !

Anna Calabro’


What is the diagnosis?

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Agenda



Neck anatomy





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Thyroglossal duct anatomy and embryology

https://my.statdx.com/

The thyroglossal duct runs from

the base of tongue at the foramen

caecum to the thyroid gland.

The embryonic thyroid gland

travels through the duct to reach its

final normal position.

Normally, at 5-6 gestational

weeks, the thyroglossal duct then

involutes, but when the duct

persists, a thyroglossal duct cyst

can develop anywhere along this

tract.

Anna Calabro’


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Thyroglossal duct anatomy and embryology

TDC LOCATION:

The location is in the midline or

paramedian.

65% infrahyoidal,

20% suprahyoidal,

15% at the level of the hyoid

bone

http://www.radiologyassistant.nl/ml

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They typically present during childhood (90%

before the age of 10), or remain asymptomatic

until they become infected, in which case they can

present at any time.

Thyroglossal duct cysts account for 70% of all

congenital neck anomalies, and are the second

most common benign neck mass, after

lymphadenopathy.

Anna Calabro’


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TDC Epidemiology

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Agenda



Neck anatomy





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TDC radiographics features

Best diagnostic clue: Midline/paramidline infrahyoid or hyoid level cystic neck mass

Embedded in strap muscles

Wall may enhance if infected

Anna Calabro’


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TDC radiographics features: US

Ultrasound: Unless infected, they are painless, fluctuant masses which spread the strap muscles. The fluid is usually anechoic and the walls are thin, without internal vascularity.

However, in some cases, the internal fluid may contain debris.

If there is associated infection, there may be surrounding inflammatory change.

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TDC radiographic features: MR

§ T1 - typically low signal (in uncomplicated non infected cases)

§ T2 - typically high signal

§ T1 C+ (Gd) - no enhancement in uncomplicated cysts, thin peripheral enhancement may be seen

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TDC radiographics features on CT: companion patient #1

Axial CT head, post contrast

cystic lesion

embedded in the strap musculature

compression of thyroid cartilage confirms lesion to be benign


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TDC radiographics features on CT: companion patient #2

http://emedicine.medscape.com

Sagittal CT head and neck, post contrast

thin band of tissue (white arrow)

connecting the TDC with the

native thyroid gland inferiorly.

note location of TDC in relation

to the hyoid bone

Anna Calabro’


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Agenda



Neck anatomy



Differential diagnoses of TDC


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Differential Diagnoses of TDC

Lymphatic malformation

Dermoid or epidermoid cysts in oral cavity

Lingual thyroid

Submandibular or sublingual space

abscess

Mixed laryngocele

Delphian chain necrotic node

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TDC DDx: Lymphatic malformations

A lymphatic malformation is a cystic mass in the head or neck that results

from an abnormal formation of embryonic lymphatic vessels;

There are two main types of lymphatic malformations:

lymphangioma - a group of lymphatic vessels that form a mass or lump.

cystic hygroma - a large cyst or pocket of lymphatic fluid that results from

blocked lymphatic vessels.

Unilocular or multilocular (sponge-like)

Focal or trans-spatial (diffuse/infiltrative)

Posterior to the SCM

Association with neurofibromatosis

Anna Calabro’


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TDC DDx: Lymphatic malformations on CT and MR

Anna Calabro’


www.medscape.com www.wiki.uiowa.edu

Axial CT neck, post contrast Axial MR neck, T2

on CT: Low attenuation non-enhancing left neck mass that extends to

the posterior paraspinal soft tissues of the upper back.

on MR: T2 hyperintense lesion

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TDC DDx: Oral cavity dermoid and epidermoid cysts

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Oral dermoid cysts

may be congenital or acquired

most commonly involve the floor of the mouth, submandibular space,

sublingual space, or root of tongue

CONTENT: fatty, fluid, or mixed components

Epidermoid cysts

benign developmental anomalies

they present as a slow-growing asymptomatic mass and are usually

diagnosed only after they have reached a considerable size. They may

obstruct the upper airway and gastrointestinal tract and potentially can

be fatal

CONTENT: only fluid-filled

Neither directly involves hyoid bone

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Anna Calabro’


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https://wiki.uiowa.edu

On MR: On T1 fatty elements appear bright, fluid dark

On T2 fat is dark and fluid is bright

Axial MR neck, T1 Axial MR neck, T2

https://wiki.uiowa.edu

TDC DDx: Oral cavity dermoid and epidermoid cysts on MR

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TDC DDx: Oral cavity dermoid and epidermoid cysts on CT

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http://www.ncbi.nlm.nih.gov

Sagittal CT head

On CT: Low density lesion, a variety of internal appearances depending

on composition, wall may enhance with contrast

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TDC DDx: Lingual thyroid

A lingual thyroid is a specific type of ectopic thyroid, and results from

lack of normal caudal migration of the thyroid gland from foramen

caecum down to its normal location anterior to the larynx and upper

trachea.

Most common location is at the base of tongue

Many patients are asymptomatic .In symptomatic patients the lingual

mass may result in dysphagia, bleeding from mucosal ulceration, or

even air-way obstruction (more common in infants).

On CT without contrast: hyperdense soft tissue mass, of the same

attenuation as normal thyroid tissue. It is hyperdense on account of

the accumulation of iodine within the gland.

On CT with contrast: the entire gland demonstrates prominent

homogenous enhancement just like the normal thyroid gland.

Anna Calabro’


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TDC DDx: Lingual thyroid on CT

Anna Calabro’


http://www.mypacs.net

CT without contrast: hyperdense soft tissue mass

CT with contrast: prominent homogenous enhancement

TDC DDx: Lingual thyroid on CT

Axial CT neck, post contrast Sagittal Head and neck


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TDC DDx: Lingual thyroid on CT and MRI

Anna Calabro’



TDC DDx: Lingual thyroid on MR

Sagittal MR head and neck, T2 Sagittal MR head and neck, T1

MRI: T1 - iso to hyperintense to muscle mass

T2 - can vary from hypo to iso to hyperintense to muscle

T1 C+ (Gd) - homogeneous contrast enhancement


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TDC DDx: Submandibular or sublingual space abscess

Location:

- the submandibular space is superior the hyoid bone, lateral or

superficial to the mylohyoid muscle sling, and deep to the platysma

muscle.

- the sublingual space is deep and medial to the mylohyoid muscle and

lateral to the genihyoid/genioglossus muscles. It communicates with the

posterior superior submandibular space and inferior pararpharyngeal

space.

Origin: Odontogenic or salivary gland infection due to a duct calculus.

Not embedded within strap muscles

Thick enhancing wall around collections of pus.

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TDC DDx: Submandibular space abscess on CT

Anna Calabro’


Axial CT neck, post contrast Coronal CT head, bone window

http://radiologypics.com

On post contrast CT: hypodense area representing fluid collection in the

submandibular space, due to and abscess

On bone window CT: lucency in the rigth side of the mandible, which

explains the odontogenic origin of the abscess

http://radiologypics.com

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TDC DDx: Sublingual space abscess on CT

Anna Calabro’


http://www.medscape.com

Axial CT head, post contrast Axial CT head, bone window

On contrast CT: hypodense lesion representing an abscess in the

sublingual space

On bone window CT: lucency on the mandible explains the odontogenic

origin of the abscess

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TDC DDx: Mixed laryngocele

Traces back to laryngeal origin

Not embedded within strap muscles

Extends both internally into the airway and externally

through the thyrohyoid membrane

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TDC DDx: Mixed laryngocele on CT

Anna Calabro’


Mixed internal and external laryngocele that shows air density.

http://www.ncbi.nlm.nih.gov

Axial neck CT

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TDC DDx: Delphian chain necrotic node (prelaryngeal)

May be difficult to differentiate from infected TGDC

Rare in children

At level of sternum

Involvement of this node can be as a result as diffuse

nodal involvement in SCC (H&N), or in isolation from

direct lymphatic spread of laryngeal cancer through the

anterior commissure. Thyroid carcinomas may also

involve this node.

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TDC DDx: Delphian chain necrotic node on CT

Anna Calabro’



Axial CT neck, post contrast

Hypodense round lesion,

with peripheral rim

enhancement *

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Agenda



Neck anatomy



Differential diagnoses of TDC


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Necrotic lymphadenopathy (papillary thyroid

and squamous cell ca nodal mets, HPV

lymphadenitis)

Cystic Hygroma (posterior neck)

Branchial cleft cysts (type 2)

Laryngocele

Abscess

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Cystic Hygroma – Key facts

Most common form of Lymphangioma

Congenital benign non-capsulated lesion arising from expanding embryonic lymph 'lakes' that do not develop normal lymphatic drainage.

90% in children 10% in young adults. May occur anywhere in the head and neck. Mostly located in posterior cervical space. 10% extend into the mediastinum.

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Cystic Hygroma on MRI

Multiloculated lesion in the posterior cervical space

On T2 weighted image, the lesion has a fluid intensity

There is no enhancement on the T1 weighted image

Axial MRI neck, T2, fatsat Coronal MRI neck, T1 www.radiologyassistant.nl

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Second branchial cleft cyst – Key facts

It’s a cystic dilation of remnant of

the 2nd branchial apparatus

95% of all branchial cleft

anomalies arise from the second

branchial cleft.

Most common presentation: cyst,

sometimes in combination with a

sinus or fistula.

www.surgicalcore.org

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Second branchial cleft cyst

■ Most common location: posterior to the

submandibular gland and anterior

margin of the SCM muscle

web.uni-plovdiv.bg

Anna Calabro’


http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=Zpg3O9sl3sNVRM&tbnid=SuYCQ3euFZIrmM:&ved=0CAUQjRw&url=http%252525253A%252525252F%252525252Fweb.uni-plovdiv.bg%252525252Fstu1104541018%252525252Fdocs%252525252Fres%252525252Fskandalakis'%252525252520surgical%252525252520anatomy%252525252520-%2525252525202004%252525252FChapter%25252525252001_%252525252520Neck.htm&ei=g4lRU974F-TKsQTHvYGgAg&bvm=bv.65058239,d.aWc&psig=AFQjCNEUk4lHhbnB_Zx-dxrg6vaLT9PFVg&ust=1397938854519380

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Second branchial cleft cyst on US

Usually sharply demarcated

Echogenicity is variable:

- anechoic - 41%

- homogeneously hypoechoic with internal debris - 24%

- pseudosolid - 12%

- heterogeneous - 23%


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Second branchial cleft cyst on CT Axial CT neck, post contrast

Rounded, sharply circumscribed

structure, with central fluid

density

Fairly thick wall with subtle

peripheral enhancement

Location: posterior to

submandibular gland and

anterior/deep to SCM

Infection: fat stranding of the

adjacent fat planes

Anterior displacement and mass

effect with extrinsic compression of

the left internal jugular vein www.radiopaedia.org

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Second branchial cleft cyst on MR


T1 - variable signal

dependant on protein

content.

- high protein content : high

signal

- low protein content : low

signal (as in image)

T2 - usually high signal

T1 C+ (Gd) - no

enhancement in

uncomplicated lesions.

The lesion shows edge

enhancement post-

Gadolinium.

Axial MRI neck, T1 Axial MRI neck, T1 C+ (Gd)

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Laryngocele: anatomy

Laryngocele: abnormal

dilation of the laryngeal

saccule.

The laryngeal ventricle is a

slit-like opening between the

false and true vocal cords.

It is the anatomic landmark

between supraglottis and

glottis.

The ventricle extends laterally

and then cranially into the

paraglottic space.

Anna Calabro’


http://web.uni-plovdiv.bg

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Laryngocele: mechanism When the opening of the

laryngeal ventricle is completely obstructed by a tumor, the mucosa in the paraglottic space continues to produce fluid. This results in a fluid-filled internal laryngocele (does not cross the thyrohyoid membrane)

When the opening of the laryngeal ventricle is partially obstructed, a pressure-valve mechanism may result in an air-containing internal laryngocele.

Anna Calabro’


http://www.hxbenefit.com

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Laryngocele on CT

Anna Calabro’


Neck anatomy is difficult to learn. Try to recognize as many anatomic

and pathologic structures as you can, in the coronal CT images on the

right, using the left image as a guide, then continue.

http://www.hxbenefit.com http://home.earthlink.net

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Laryngocele on CT

Anna Calabro’


jvjvf Coronal CT head

Anatomic structures from

the top:

-hyoid bone

-epiglottis

-thyrohyoid membrane

-thyroid cartilage

-cricoid cartilage

Pathology structures:

-tumor/mass

-INTERNAL laryngocele

-EXTERNAL laryngocele

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http://home.earthlink.net

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Laryngocele on CT

Axial CT neck , lower cut Axial CT neck, higher cut

Well defined, air, fluid or pus filled lesion related to the paraglottic

space, which has continuity with the laryngeal ventricle.

Secondary internal and external laryngocele caused by a tumor at the

level of the laryngeal ventricle.

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Laryngocele Types

INTERNAL - the dilated ventricular saccule is confined to the paralaryngeal space

EXTERNAL - the saccule herniates through the thyrohyoid membrane (anteriorly)

MIXED - has components both inside and outside the larynx

The lesion can be air-filled (laryngocele)

fluid filled (laryngeal mucocele)

pus filled (laryngopyocele)

Anna Calabro’


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References Branstetter, BF and Weissman JL. Normal Anatomy of the Neck with CT and MR Imaging Correlation. Radiologic Clinics of North

America; Sept 2000 38:925-940.

Emerick, Kevin, and Derrick Lin. Differential diagnosis of a neck mass; May 2010.

Ahuja AT, King AD, King W et-al. Thyroglossal duct cysts: sonographic appearances in adults. AJNR Am J Neuroradiol. 1999;20 (4): 579-82. AJNR Am J

Meuwly JY, Lepori D, Theumann N et-al. Multimodality imaging evaluation of the pediatric neck: techniques and spectrum of findings. Radiographics. 25 (4): 931-48

http://pediatric-ent.com/2011/09/lump-or-mass-in-the-neck/#bca

http://radiopaedia.org/articles

http://www.radiologyassistant.nl/en/p49c603213caff/infrahyoid-neck.html#i4aedf5ff2169a

https://my.statdx.com/

http://emedicine.medscape.com/article/1346365-overview#a20

http://www.surgicalcore.org/popup/55306

http://web.uni-plovdiv.bg/stu1104541018/docs/res/skandalakis'%20surgical%20anatomy%20-%202004/Chapter%2001_%20Neck.htm

http://radiopaedia.org/articles/second-branchial-cleft-cyst

http://www.medscape.com/viewarticle/510370_3

https://wiki.uiowa.edu/display/protocols/Lymphatic+Malformation+Rads

http://web.uni-plovdiv.bg/stu1104541018/docs/res/skandalakis'%20surgical%20anatomy%20-%202004/Chapter%2005_%20Larynx.htm

http://www.hxbenefit.com/laryngocele.html

http://home.earthlink.net/~radiologist/tf/030705.htm

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References

Anna Calabro’


Curtin, HD. "Larynx." In Head and Neck Imaging, Som and Curtin, eds. St. Louis: Mosby-Yearbook. pp 665-671.

http://www.brown.edu/Departments/Diagnostic_Imaging/cases/hn.html

https://wiki.uiowa.edu/display/protocols/Dermoid+Cysts+Rads

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3781235/

http://www.mypacs.net/cases/LINGUAL-THYROID-57329773.html

http://radiologypics.com/2013/02/14/submandibular-space-abscess/

http://www.medscape.com/viewarticle/729323_3

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2640037/#B12

http://www.mypacs.net/mpv4/hss/casemanager

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Acknowledgements


Jayant Boolchand, MD

Alejandro Heffess, MD

Pierre Sasson, MD

Mount Auburn Radiology Department

Anna Calabro’


(tdc) and cystic neck masses

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