Ch 1 Developmental Defects 4 Flashcards
What is the alternate name for a thyroglossal duct cyst?
thyroglossal tract cyst
The caudal segment of the thyroglossal duct
often persists, forming the ________ lobe of the thyroid gland.
pyramidal
Where do a majority of thyroglossal duct cysts develop? (please give saggital and coronal locations)
midline and adjactent to the hyoid bone
When are most thyroglossal duct cysts diagnosed? Gender?
50% before 20 years old…no sex predilection
Thyroglossal duct cyst histo: 4 types of epi lining? Is thyroid tissue required?
- columnar 2.stratified squamous 3. cuboidal 4.small intestine….thyroid tissue not a consistent finding
What is the term for the surgical procedure to remove a thyroglossal duct cyst? What is the recurrecne rate with this procedure?
Sistrunk procedure (removal of cyst with midline hyoid bone and muscle tissue)…less than 10% (much higher with less aggressive removal)
What % of thyroglossal duct cysts have progressed to cancer? What type of cancer?
1-2%…papillary thyroid carcinoma (mets rare, good prog)
What is the alternate term for a branchial cleft cyst?
cervical lymphoepithelial cyst
A majority of branchial cleft cysts are derived from which arch? What is the %? Which other arches can cause cysts?
95% from the 2nd branchial arch…5% 1st, 3rd, and 4th arches
2 most common sites for branchial cleft cysts of the 2nd arch?
- upper lateral neck anterior
2. deep to the sternocleidomastoid muscle
What is the age range for patients with a branchial cleft cyst?
10-40 years old
What % of branchial cleft cyst are from the 1st arch? Where do they clinically present?
1%…near the parotid gland
Where do branchial cleft cysts from the 3rd and 4th cleft develop? (2 sites)
- lower neck
2. mediastinum
Branchial cleft cyst histo: 90% are which type of epithelial lining? What is the other possibility? What is often found in the cyst wall?
90% stratified squamous w/ or w/o keratinization….respiratory…lymphoid tissue in the cyst wall (hence cervical lymphoepithelial cyst)
What is the recurrence for branchial cleft cyst?
almost never recurs
Oral lymphoepithelial cyst is microscopically similar to which developmental lesion?
branchial cleft cyst (cervical lymphoepithelial cyst)
What are the three components to the Waldeyer Ring?
- palatine tonsils 2. lingual tonsils 3.pharyngeal adenoids
What are three locations other than the waldeyer ring for oral lymphoepithelial cysts?
- FOM
- Ventral tongue
- soft palate
What age group is most common for oral lymphoepithelial cysts?
young adults
What is the recurrence for oral lymphoepithelial cysts?
shouldn’t recur
What is the alternate name for hemihyperplasia?
Hemihypertrophy (the tissues are hyperplastic though)
What is is a rare developmental anomaly characterized
by asymmetric overgrowth of one or more body parts?
Hemihyperplasia
YAY! Memorize that box! What are the 12 malformation syndromes associated with hemihyperplasia?
- Beckwith-Wiedmann syndrome (macroglossia, nevus flammeus)
- Neurofibromatosis (NFs + cafe-au-lait coast of California)
- Kipple-Trenaunay-Weber syndrome (Triad: port-wine stain, abnormal overgrowth of soft tissues and bones, and vein malformations)
- Proteus syndrome (rare condition characterized by overgrowth of the bones, skin, and other tissues.)
- McCune-Albright syndrome (Polyostotic FD + cafe-au-lait coast of Maine + endocrineopathies)
- Epidermal nevus syndrome (epidermal nevi + CNS problems)
- Triploid/diploid mixoploidy (truncal obesity, body/facial asymmetry, weak muscle tone (hypotonia), delays in growth, mild differences in facial features, fusion or webbing between some of the fingers and/or toes (syndactyly) and irregularities in the skin pigmentation)
- Langer-Giedion syndrome (Trichorhinophalangeal syndrome (TRPS) type 2..rare gene deletion syndrome with distinct facial features and bone abnormalities)
- Multiple exostoses syndrome (self explanatory)
- Maffucci syndrome (multiple enchondromas + soft tissue hemangiomas)
- Ollier syndrome (multiple enchondromas only)
- Segmental odontomaxillary dysplasia (missing PM, Becker nevus)
What defines simple vs complex hemihyperplasia?
simple: single limb; complex: entire side of body
In general, what is the gender predilection for hemihyperplasia? Which side of the body is more commonly affected?
2:1 female…the Right side
What % of hemihyperplasia pts are intellectually disabled?
20%
What 3 types of tumors are most commonly associated with hemihyperplasia?
- Wilms tumor
- Adrenal cortical carcinoma
- Hepatoblastoma
LOL what are the three alternate names for Progressive Hemifacial Atrophy (PHA)?
- Progressive Facial Hemiatrophy
- Romberg Syndrome
- Parry-Romberg syndrome
Which bacteria is suspected as a cause of progressive hemifacial atrophy (PHA)?
Borrelia (Lyme disease)
What other disorder does progressive hemifacial atrophy (PHA) resemble?
scleroderma
What is the gender predilection for progressive hemifacial atrophy (PHA)?
female
What is the term for a sharp line of demarcation, resembling a large linear scar, between normal and abnormal skin near the midline of the forehead found in progressive hemifacial atrophy (PHA)?
linear scleroderma (“en coup de sabre” - strike of the sword)
What is the term for eye involvment in progressive hemifacial atrophy (PHA)?
enophthalmos (due to loss of periorbital fat)
The mouth and nose in progressive hemifacial atrophy (PHA) are directed toward or away from the affected side?
Toward the affected side
The atrophy in progressive hemifacial atrophy (PHA) occurs over a span of how many years before stabilizing?
2 to 20 years
What is the alternate name for Segmental Odontomaxillary Dysplasia?
Hemimaxillofacial dysplasia
What two conditions can Segmental Odontomaxillary Dysplasia (SOD) clinically resemble?
fibrous dysplasia and hemifacial hyperplasia
Which permanent teeth are typically missing in Segmental Odontomaxillary Dysplasia (SOD)?
One or both of the MAXILLARY premolars
What skin lesion was found on ONE patient with segmental odontomaxillary dysplasia (SOD)? What are the two components of this skin lesion?
BECKER NEVUS - Hypertrichosis and hyperpigmentation
What is the alternate name for Crouzon syndrome?
Craniofacial dysostosis
________ is one of a rare group of syndromes
characterized by craniosynostosis, or premature closing of the cranial sutures.
Crouzon syndrome
What is the gene mutation associated with Crouzon syndrome?
FGFR2 (chrom 10q26)
What is the inheritance pattern and prevelence of Crouzon syndrome?
AD…1 of 65,000 live births - significant amount of sporatic cases, usually with increased PATERNAL age
What are the three terms for the craniofacial malformations of Crouzon syndrome?
- Brachycephaly (short head)
- Scaphocephaly (boat-shaped head)
- Trigonocephaly (triangle-shaped head)
What is the term for the head shape in the most severely affected Crouzon disease patients?
“cloverleaf” skull (kleeblattschadel deformity)
What can a skull radiograph show in Crouzon syndrome?
“beaten-metal” pattern (increased digital markings)
What 3 disorders show a “beaten-metal/copper” pattern on skull radiographs?
1.Childhood hypophosphotasia = beaten copper 2. Crouzon syndrome = beaten metal 3. Apert syndrome same as Crouzon
What is the alternate term for apert syndrome?
Acrocephalosyndactyly
What is the gene mutation, inheritance, and prevelence of Apert syndrome? (hint: think Crouzon syndrome)
FGFR2 (chrom 10q26)…AD…1:65,000…increased paternal age for sporatic cases (all the same as Crouzon syn)
What are the technical term and nickname for the clinical presentation of the skull in Apert syndrome?
Acrobrachycephaly … tower skull
What is the term for the clinical skull formation in severely affected Apert syndrome patients?
“cloverleaf” skull (kleeblattschadel deformity) - yes, the same as Crouzon
What is the characteristic feature of Apert syndrome that separates it from Crouzon?
limb defects - syndactyly of the 2nd,3rd,4th digits of the hands AND feet almost always obderved
30% of Apert syndrome patients have clefts of what two oral locations?
soft palate or uvula (bifid uvula)
What substance is assocated with the lateral hard palate swellings in Apert syndrome patients? What is the term for the clinical appearance created by these swellings?
GAGs - esp hyaluronic acid…a PSEUDOcleft hard palate
35% of Apert pts are missing which teeth?
Maxillary lateral incisiors or mandibular second premolars
What are the 2 alternate names for Mandibulofacial Dysostosis?
- Treacher Collins syndrome
2. Franceschetti-Zwhalen-Klein syndrome
Mandibulofacial dysostosis (Treacher Collins) is characterized by defects of structures derived from which embryollogic structures?
first and second branchial arches
Mandibulofacial dysostosis (Treacher Collins) inheritence pattern and prevelence? What % represent new mutations?
AD….1 in 50,000…60% new….PATERNAL age
Mandibulofacial dysostosis (Treacher Collins) what is the gene mutation?
TCOF1 (aka treacle) chromo 5q32-q33.1
Mandibulofacial dysostosis (Treacher Collins) 75% of pts have this notch that occurs on the outer portion of the lower eyelid
Coloboma
Mandibulofacial dysostosis (Treacher Collins) 2 orofacial defects?
- Clefting (facial or palate)
2. Parotid gland hypoplasia/aplasia
