oto osseous dysplasias Flashcards
Describe the histologic appearance of fibrous
dysplasia.
Replacement of normal bone with benign fibrous tissue and
irregular trabeculae of immature woven bone (“Chinese
characters” appearance)
What are indications for surgical treatment of
fibrous dysplasia of the skull base or craniofacial
skeleton?
Generally, only symptomatic patients should undergo
surgery (cranial neuropathies, vision loss, disfigurement).
Some advocate optic canal decompression for asymptomatic patients with radiographic evidence of optic canal impingement, but this is debated.
What clinical findings are seen in McCune-Albright
syndrome?
Polyostotic fibrous dysplasia, abnormal skin pigmentation
(such as café-au-lait spots), and endocrine dysfunction
(such as precocious puberty in girls)
What is the cause of hearing loss in patients with
autosomal recessive osteopetrosis?
Most commonly, hearing loss is conductive, with disordered
ossicular chain bony overgrowth, external auditory canal stensosis, stapes fixation, loss of temporal bone pneuma-
tization, and recurrent otitis media resulting from eustachian tube narrowing. SNHL can also occur, likely from narrowing of the bony internal auditory canal.
What are the cause and the most common
treatment for patients with recurrent facial palsy in
the setting of osteopetrosis?
Compression of the facial nerve throughout its bony canal
secondary to greatly increased bone density seen in osteopetrosis can lead to episodic, recurrent facial weakness.
Complete facial nerve decompression can be attempted to
manage this, because some residual and slowly progressive
weakness are often seen after each episode.
What is the treatment for hearing loss secondary
to Paget disease of bone involving the temporal
bone?
Medical therapy consisting of bisphosphonates and calcitonin is the mainstay of therapy. Amplification may also be considered. Generally, hearing loss from bony abnormalities
attributable to Paget disease is not correctable by surgical
means.
