Laryngeal Cancer Flashcards
What are the three divisions of the larynx?
supraglottis
glottis
subglottis
supraglottis (anatomy)(5)
aryepiglottic folds arytenoids, epiglottis (supra and infra), false vocal cords, ventricles (sometimes pharyngoepiglottic folds)
glottis (anatomy)(4)
anterior commissure,
floor of the ventricle, interarytenoid area (posterior commissure),
true vocal cords
What is the axial line of demarcation between the supraglottic and the glottic larynx?
apex of the ventricle
Describe the position of the subglottis anatomically.
The demarcation between the glottis and subglottis is ill-defined.
It is usually considered to extend from a point 5 mm below the free margin of the vocal cord to the inferior border cricoid cartilage or
10 mm below the apex of the ventricle.
What is the only complete ring of the upper airway?
Cricoid cartilage
Which group of muscles primarily control the movement of the cords?
Intrinsic muscles
Which group of muscles are concerned primarily with swallowing?
Extrinsic muscles
What muscle draws the larynx anteriorly and inferiorly when contracting resulting to an increased pitch of voice?
Cricothyroid muscle
What is the innervation of the intrinsic muscles of the larynx?
Recurrent laryngeal nerve
What is the innervation of the cricothyroid muslce?
Superior laryngeal nerve
The preepiglottic and paraglottic fat spaces are essentially one contiguous space lying between the external framework of the thyroid cartilage and hyoid bone and the inner framework of the epiglottis and intrinsic muscles.
TRUE or FALSE?
True
Because of the abundance of capillary lymphatics arise in the preepiglottic and paraglottic area, invasion of the fat space seldom often leads to lymph node metastases, in contrast to the glottic area which essentially has very limited lymphatics.
False.
Because few capillary lymphatics arise in this area, invasion of the fat space seldom leads to lymph node metastases.
Boundaries of the fat space
anterior/lateral
inferior
superior
medial
inferiorly-conus elasticus
anterolaterally- thyroid ala, thyrohyoid membrane, quadrangular membrane, hyoid
superiorly- hyoepiglottic ligament
medial- fascia of the intrinsic muscles
What is the histology of the laryngeal surface of the epiglottis and the free margins of the vocal cords?
How about the remaining mucosa?
squamous epithelium
pseudostratified ciliated columnar epithelium
Where do branches of laryngeal arteries come from?
superior and inferior thyroid arteries
The supraglottic structures have a rich capillary plexus; the trunks pass through the preepiglottic space and thyrohyoid membrane.
TRUE or FALSE?
True
The subglottic area has relatively few capillary lymphatics. The lymphatic
trunks pass through the cricothyroid membrane to the pretracheal (delphian)
lymph nodes in the region of the thyroid isthmus. The subglottic area also drains
posteriorly through the cricotracheal membrane, with some trunks going to the
paratracheal (level VI) lymph nodes and others continuing to the inferior jugular
(level IV) chain.
TRUE or FALSE?
True
Laryngeal is the most common head and neck mucosal cancer.
TRUE or FALSE?
False.
2nd most common
Glottic carcinoma is more common than supraglottic carcinoma.
TRUE or FALSE?
True.
2:1
What is the most commonly implicated etiology in the development of laryngeal cancer?
Cigarette smoking.
The risk of
tobacco-related cancers of the upper alimentary and respiratory tracts declines
among former smokers after __ years and is said to approach the risk of
nonsmokers after __ years of abstention.
5 and 10 respectively.
Where is the most common site of glottic cancer?
anterior portion of the cord
Involvement of the cords on their external surface occurs early,
submucosal extension by the way of the paraglottic space occurs later.
TRUE or FALSE?
False.
Vice-versa
Thyroid cartilage invasion usually occurs in the ossified section of the cartilage.
TRUE or FALSE?
True.
commonly in the region of the anterior commissure tendon or the junction of the anterior1/4 and posterior 3/4 of the thyroid lamina.
Causes of vocal cord fixation
invasion or destruction of the vocal cord muscle,
invasion of the cricoarytenoid muscle or joint
invasion of the RLN (rarely)
Perineural spread is common in laryngeal cancers.
TRUE or FALSE?
False.
It is uncommon.
Tumors of the infrahyoid epiglottis involve the valeculla and base of tongue only through the involvement of suprahyoid epiglottis.
TRUE or FALSE?
False.
tumor may present in the vallecula and base of tongue without
involving the suprahyoid epiglottis
Which subsite of the larynx is most rarely involved, and if involved is difficult to know whether it originated from there or just an extension?
Subglottic larynx
Supraglottic SCC and glottic tumors mainly spread through the lymphatics via which nodal level?
Level II
Anterior commissure and
anterior subglottic invasion are also associated with involvement of the which nodes?
midline pretracheal lymph node (level VI)
Most common symptom of early true vocal cord cancer?
Hoarseness
Most frequent initial symptom of supraglottic cancer?
Odynophagia
First “sign” of supraglottic cancer
Neck mass
How to determine vocal cord mobility in fiber-optic examination of the vocal cords?
Ask the patient to say "ee" (adduction) and sniff (abduction)
In fiberoptic examination, what is/are indirect sign/s of preepiglottic space invasion?
ulceration of infrahyoid epiglottis
fullness of the vallecula
Why is CT scan preferred over MRI in the imaging of laryngeal cancer?
MRI scanning time is longer which produces motion artifact.
AJCC 2017 (8th ed)
Staging: Supraglottic
T1
Tumor limited to one subsite of supraglottis with normal vocal cord mobility