H&N Benign Lesions Flashcards
What are the common aetiologies of neck masses according to age group?
What are branchial arches
- mesenchymal swellings of mesoderm/ectoderm/endoderm that form the craniofacial structures wk 4.5
- 5-6 paired arches, Each contains
- core mesoderm, ectoderm on surface and endoderm inside
- artery (formed by mesoderm)
- muscle (formed by mesoderm)
- nerve
- cartilage rod
- ligament
Describe the development of craniofacial structures
- week 3 - formed trilaminar disc and outgrowth of neuroectoderm, neural disc, neural plate and tube
- wk 4 - migration of arches to form primitive face with stomodeum between 1st arch and frontonasal prominence
- wk5 -8 - formation and coalescence of facial prominence (FNP, MxP, MdP)
Define the derivatives of each arch, pouch, groove, cleft
Describe development of thyroid
- wk 3, involution of epithelium (diverticulum) at tongue and ascent below hyoid, contains derivatives of thyroid
- if thin duct fails to degenerate, left with tract connected at foramen cecum
Describe development of masses at/near nose
- foramen cecum usually obliterated separating anterior cranial fossa from nose
- if not obliterated, can have resulting dermoid, glioma, encephalocele
What is your DDX for congenital nasal mass
dermoid
glioma
encephalocele
What is a dermoid?
- epithelium lined sac containing ectoderm and mesoderm = sequestration of ectodermal remnants remaining during embryonic fusion at suture lines
- can extend intracranial
- cyst lined by squamous epithelium and contianing secretions from hair follicles, sweat/sebaceous glands
How are dermoid classifed?
By location
- midline submental, nasal dorsum, columella, along brow, along suture lines
What investigations would help in the management?
CT - for intracranial extension
- may identify bifid crita galli, enlarged foramen cecum, wide NF suture, bony destruction in NF region
MRI - for delineation of involved soft tissues
What is the treatment
Non-operative observation
Operative
- Intracranial lesion - requires frontal craniotomy and external approach with use of lacrimal probe and skin excision if sinus present
- Extracranial only - external approach
What is a nasal glioma?
- mass of EXTRAdural glial tissue on a stalk - not connected to dura/brain
What are associated clinical findings of a nasal glioma
- if glioma is INtERnal: may have chronic nasal obstruction/discharge ,widened nasal base
- if glioma is EXternal - presents as noncompressible mass with no fluctuation w crying
What is an encephalocele
How are encephaloceles classifed?
- herniation of meninges +/- herniation of brain tissue
By location
occipital
pareital
frontal - nasoethmoid, nasofrontal, nasoorbital
What is the treatment
- excision with comines intracranial and extracranil approach
- Bicoronal, bifrontal osteotomy, exposur eof mass
- Reconstruction - dural closure (TPF, temporalis, fascia lata), bone recon of anterior cranial fossa, obliteration of cranial/nasal communication, orbital osteotomies or facial bipartition
What is your differential diagnosis of a benign neck mass according to location?
MIDLINE
- laryngocele
- thyroglosal duct cyst
- ranula
- thyroid adenoma, goiter
- thymus gland lesion
- dermoid
LATERAL
- branchial cleft/cyst
- carotid body tumor (glomus tumor)
- cystic hygroma
What is a laryngocele and how do you manage
abnormal dilation of the laryngeal saccule
= congenitla or acquired (2’ high intralaryngeal pressure w instruments/cough
- History: ass. gurgling, empyting/swelling, dysphagia/dysphonia
- Investigation: endoscopy and CT
- treat: excision
What is a thyroglossal duct cyst and how do you manage
- persistant thryoglossal duct and resulting cyst - duct lined from base of tongue to hyoid during development o fthyroid
- presents in 2nd decase, elevates w tongue protrusion
- Need to confirm presence of normal thryoid prior to excision - U/S and TSH
- excision for tx
What is the etiology of branchial cleft cyst/sinus/fistula
- failure of 2nd BA to grow caudally over 3rd ad 4th with obliteration of openings
- cyst/sinus/fistula usually found along anteriro border of SCM, below angle of manidble or preauricular
1st BA -> not common, near parotid/CN7 , if excision- use intra-op nerve stimulation and excise segment of cartilage at EAC
2nd BA-> most common, located along anterior sternal border. MAybe anywhere along tract from skin along SCM, through platysma, over CN12,9, through carotid bifurcation into tonsillar fossa
3rd,4th - rare, enter larynx
What is the clinical presentation of a B cleft cyst/fisutla/sinus
- ass. UTI w pain, discharge, fluctuating or slowing increasing in size
What is a glomus tumor
Where are they located in the head and neck
Benign neuroendocrine mass, also known as a paraganglioma
- Carotid bifuration
- Jugular bulb at skull base - most common
- Vagus nerve
- Middle ear cavity
What are treatment options?
embolization
excision
