Plastics Flashcards
What drains into inferior meatus? Middle meatus? Superior meatus? Sphenoethmoidal recess?
Inferior meatus: nasolacrimal duct
Middle meatus: maxillary sinus, anterior and middle ethmoid sinuses, frontal sinus
Superior meatus: posterior ethmoid sinus
Sphenoethmoidal recess: sphenoid sinus
Differential for orbital mass with bony destruction in children
Malignancy: primary rhabdomyosarcoma, metastatic neuroblastoma, granulocytic sarcoma (rapidly progressive inflammation)
Histiocytic disorders, e.g. Langerhans cell histiocytosis (recurrent relapsing episodes of inflammation as opposed to rapidly progressive)
What treatment is contraindicated in patients with orbital masses causing bony destruction?
Corticosteroids
2 most common sites for orbital metastasis
Extraocular muscles (abundant vascular supply)
Bone marrow space of the sphenoid bone second most common (high volume of low-flow blood)
Biopsy of the ___ lobe of the lacrimal gland should be avoided because of potential damage to the ___ ___.
Biopsy of the palpebral lobe of the lacrimal gland should be avoided because of potential damage to the lacrimal duct.
Histology of mucormycosis
Nonseptate, large branching hyphae
Why can zygomycoses like Mucor cause vascular occlusions?
Fungi have propensity for invading blood vessel walls, causing thrombosing vasculitis
What is the most common cause of proptosis in a child? What are some other differentials? (3)
Orbital cellulitis
Orbital rhabdomyosarcoma
Intraorbital foreign body
Idiopathic orbital inflammation
Where do the marginal and peripheral arcades of the upper eyelid, and the arterial arcade of the lower eyelid, come from?
Anastomosis between the ICA (to ophthalmic artery to supraorbital and lacrimal artery) and ECA (to angular and temporal artery) circulations
Where is the marginal arcade found?
2 mm superior to the eyelid margin just anterior to the tarsus
Where is the peripheral arcade found?
Superior to the tarsus, between the levator aponeurosis and the Müller muscle
Where is the arterial arcade found?
Just inferior to the tarsus in the lower eyelid
How does repair of cicatricial ENtropion differ from that for cicatricial ECtropion?
Cicatricial entropion: posterior lamella must be augmented with a mucous membrane graft (buccal or amniotic)
Cicatricial ectropion: anterior lamella requires a skin graft
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the ___ ___. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the lacrimal sac. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The lacrimal gland is not fully functional until the infant is about __ weeks old. Thus, newborn infants do not produce tears when crying.
The lacrimal gland is not fully functional until the infant is about 6 weeks old. Thus, newborn infants do not produce tears when crying.
What are the most common pathogens in orbital cellulitis affecting neonates? Older children and adults? Older or immunosuppressed patients?
Neonate: S aureus and gram-negative bacilli
Older children and adults: S aureus, Strep pyogenes, Strep pneumoniae
Older or immunosuppressed: polymicrobial, including gram-negative and anaerobic organisms
What abnormality are chemotherapeutic agents such as docetaxel (or 5-fluorouracil) associated with?
Canalicular obstruction (consider prophylactic intubation, otherwise may require CDCR)
Differential for slowly progressive, superomedial (above the medial canthal tendon) orbital mass in a child? Adult?
Child: expanding skull base process, e.g. encephalocele (inferior herniation of brain tissue), meningocele (herniation of the meninges), meningoencephalocele (herniation of both) common in congenital clefting syndromes, dermoid cysts
Adult: meningocele, mucocele, lacrimal sac malignancy
5 tumors of mesenchymal origin
- Solitary fibrous tumors (e.g., hemangiopericytoma, fibrous histiocytoma)
- Rhabdomyosarcomas
- Fibrous histiocytoma
- Osteomas
- Fibrous dysplasia
A botulinum toxin injection into the ___ muscle would improve horizontal rhytids in the inferior glabellar area.
A botulinum toxin injection into the procerus muscle would improve horizontal rhytids in the inferior glabellar area.
Treatment of the ___ ___ muscles affects the more vertically oriented rhytids.
Treatment of the corrugator supercilii muscles affects the more vertically oriented rhytids (causes glabellar folds).
Treatment of the ___ muscle would improve horizontal/transverse forehead rhytids.
Treatment of the frontalis muscle would improve horizontal/transverse forehead rhytids.
Injection into the ___ ___ muscle is typically in the lateral crow’s feet” region.
Injection into the orbicularis oculi muscle is typically in the lateral crow’s feet” region.
On CT, fibrous dysplasia characteristically has a ___ appearance on imaging with sparing of the ___ ___.
On CT, fibrous dysplasia characteristically has a ground-glass appearance on imaging with sparing of the soft tissues.