Interview with John Leonetti MD, Professor of Otolaryngology, Loyola University Medial Center, Chicago, Illinois
Share:
Part Two - Cholesteatoma for Audiologists
Part Two - Cholesteatoma for Audiologists.
AO/Beck: Thanks again for joining me Dr. Leonetti. Today we're going discuss cholesteatoma.
Leonetti: Great!
AO/Beck: Let's start with a working definition of cholesteatoma please.
Leonetti: In general, a cholesteatoma is a skin cyst of the ear. There are two broad categories of cholesteatoma, congenital and acquired.
Within congenital cholesteatomas, there are two types; middle ear, and petrous apex.
Middle ear congenital cholesteatomas arise from epithelial rest cells that are inappropriately trapped in the middle ear space during early development. As you may recall from embryology, the normal middle ear space does not have epithelial cells in it. The lateral surface of the tympanic membrane is stratified squamous epithelium, but the middle ear is respiratory mucosa. Therefore, if epithelial cells get trapped in the middle ear space during development for whatever the reason may be, one cell leads to two, then four, then eight, and pretty soon you have a white pearl of skin in the middle ear space and the formation of a congenital cholesteatoma.
AO/Beck: How are these diagnosed?
Leonetti: These are almost always diagnosed during childhood, and the usual presentation is a white mass behind the eardrum, usually visualized with an otoscopic microscope in the office. These are dry middle ears, and they do not involve drainage at all. The problem is that the pediatricians will sometimes see these children for hearing loss associated with the cholesteatoma, which is typically a conductive loss, and then they are likely to diagnose otitis media and will try the child with antibiotics, which will have no impact, and then finally the child is referred to an otolaryngologist who would hopefully notice the white mass behind the intact eardrum.
AO/Beck: Is the treatment for congenital cholesteatoma always surgical removal?
Leonetti: Yes, that's the treatment, unless of course the patient is not a surgical candidate for another reason. Hopefully we see the patients early enough so that the cholesteatoma is small and the ossicular chain is still intact. If we see them later, more damage may have occurred, and in fact the entire middle ear space could be filled with the cholesteatoma. In these late presenting cases the risk of recurrence is higher and the risk of damage to the hearing and related structures is higher. So like everything else, early diagnosis leads to a better outcome with less probability of complications.
AO/Beck: So if the cholesteatoma is diagnosed early enough, can it be removed via a simple type I tympanoplasty?
Leonetti: Yes, that is certainly possible for early diagnosed cases. A 20 to 30 minute procedure where we simply lift the eardrum, remove the cholesteatoma and put the eardrum back in place and that's the end of the problem. By the same token, a late diagnosed case may require a tympanolplasty, an ossiculoplasty and a mastoidectomy, depending on the extent of damage from the cholesteatoma.
AO/Beck: Let's discuss the petrous apex congenital cholesteatoma.
Leonetti: Sure. Usually, the petrous apex congenital cholesteatoma is not diagnosed until the patient is an adult. Interestingly, the hearing loss associated with these is usually sensorineural, not conductive. The reason is that the cyst erodes the anterior wall of the internal auditory canal causing irritation of the auditory nerve and possibly damaging the blood supply to the cochlear nerve. So, as you can imagine, in addition to sensorineural hearing loss, you can have tinnitus too, and if the facial nerve is affected, you can have facial twitching and perhaps in extreme cases facial paralysis too. Additionally, a patient could have headaches due to the expansion and erosion of the petrous bone.
AO/Beck: So the extent of involvement of a petrous apex cholesteatoma can be enormous. How are these diagnosed?
Leonetti: The only way to get an idea of the full involvement preoperatively, is through radiographic techniques such as the CT scan and the MRI.
AO/Beck: Thanks Dr. Leonetti. If you don't mind, let's focus a little on the acquired cholesteatoma please. I believe that is the more common type?
Leonetti: Yes, that's more common. Acquired cholesteatomas are always related to sub-optimal aeration of the middle ear, which is typically associated with a mal-functioning, or non-functioning eustachian tube.
These may present as a pars flacida cholesteatoma, occurring from retraction of the tympanic membrane above the short process of the malleus, and those are also called attic cholesteatomas. These usually present with otorrhea, from the polyp and infection, but they present with normal hearing because the pars flacida is lateral to the ossicular chain. In these situations, regarding surgical treatment, we might perform an atticotomy, which is a limited mastoidectomy, and we would place a ventilation tube
in the eardrum to prevent re-retraction of the pars flacida which often results in normal hearing.
AO/Beck: What about pars tensa cholesteatomas?
Leonetti: The pars tensa cholesteatoma is a posterior-superior retraction cholesteatoma which causes early erosion of the incus and possibly the stapes too, and it also causes otorrhea with an associated conductive hearing loss. The diagnosis is made by microscopic otoscopy and the extent of the cholesteatoma can only be determined by CT. The CT results are then used to determine the surgical treatment plan. So basically, if the cholesteatoma has a limited presentation into the mastoid we might use a canal wall up procedure. However, if the cholesteatoma is extensive, it may require a canal wall down procedure.
AO/Beck: Thanks Dr. Leonetti. The third and final segment of the interview will be next week and that will address mastoidectomy.
Leonetti: Thank you Dr. Beck
CLICK HERE TO REVIEW Part One - Tympanoplasty
AO/Beck: Thanks again for joining me Dr. Leonetti. Today we're going discuss cholesteatoma.
Leonetti: Great!
AO/Beck: Let's start with a working definition of cholesteatoma please.
Leonetti: In general, a cholesteatoma is a skin cyst of the ear. There are two broad categories of cholesteatoma, congenital and acquired.
Within congenital cholesteatomas, there are two types; middle ear, and petrous apex.
Middle ear congenital cholesteatomas arise from epithelial rest cells that are inappropriately trapped in the middle ear space during early development. As you may recall from embryology, the normal middle ear space does not have epithelial cells in it. The lateral surface of the tympanic membrane is stratified squamous epithelium, but the middle ear is respiratory mucosa. Therefore, if epithelial cells get trapped in the middle ear space during development for whatever the reason may be, one cell leads to two, then four, then eight, and pretty soon you have a white pearl of skin in the middle ear space and the formation of a congenital cholesteatoma.
AO/Beck: How are these diagnosed?
Leonetti: These are almost always diagnosed during childhood, and the usual presentation is a white mass behind the eardrum, usually visualized with an otoscopic microscope in the office. These are dry middle ears, and they do not involve drainage at all. The problem is that the pediatricians will sometimes see these children for hearing loss associated with the cholesteatoma, which is typically a conductive loss, and then they are likely to diagnose otitis media and will try the child with antibiotics, which will have no impact, and then finally the child is referred to an otolaryngologist who would hopefully notice the white mass behind the intact eardrum.
AO/Beck: Is the treatment for congenital cholesteatoma always surgical removal?
Leonetti: Yes, that's the treatment, unless of course the patient is not a surgical candidate for another reason. Hopefully we see the patients early enough so that the cholesteatoma is small and the ossicular chain is still intact. If we see them later, more damage may have occurred, and in fact the entire middle ear space could be filled with the cholesteatoma. In these late presenting cases the risk of recurrence is higher and the risk of damage to the hearing and related structures is higher. So like everything else, early diagnosis leads to a better outcome with less probability of complications.
AO/Beck: So if the cholesteatoma is diagnosed early enough, can it be removed via a simple type I tympanoplasty?
Leonetti: Yes, that is certainly possible for early diagnosed cases. A 20 to 30 minute procedure where we simply lift the eardrum, remove the cholesteatoma and put the eardrum back in place and that's the end of the problem. By the same token, a late diagnosed case may require a tympanolplasty, an ossiculoplasty and a mastoidectomy, depending on the extent of damage from the cholesteatoma.
AO/Beck: Let's discuss the petrous apex congenital cholesteatoma.
Leonetti: Sure. Usually, the petrous apex congenital cholesteatoma is not diagnosed until the patient is an adult. Interestingly, the hearing loss associated with these is usually sensorineural, not conductive. The reason is that the cyst erodes the anterior wall of the internal auditory canal causing irritation of the auditory nerve and possibly damaging the blood supply to the cochlear nerve. So, as you can imagine, in addition to sensorineural hearing loss, you can have tinnitus too, and if the facial nerve is affected, you can have facial twitching and perhaps in extreme cases facial paralysis too. Additionally, a patient could have headaches due to the expansion and erosion of the petrous bone.
AO/Beck: So the extent of involvement of a petrous apex cholesteatoma can be enormous. How are these diagnosed?
Leonetti: The only way to get an idea of the full involvement preoperatively, is through radiographic techniques such as the CT scan and the MRI.
AO/Beck: Thanks Dr. Leonetti. If you don't mind, let's focus a little on the acquired cholesteatoma please. I believe that is the more common type?
Leonetti: Yes, that's more common. Acquired cholesteatomas are always related to sub-optimal aeration of the middle ear, which is typically associated with a mal-functioning, or non-functioning eustachian tube.
These may present as a pars flacida cholesteatoma, occurring from retraction of the tympanic membrane above the short process of the malleus, and those are also called attic cholesteatomas. These usually present with otorrhea, from the polyp and infection, but they present with normal hearing because the pars flacida is lateral to the ossicular chain. In these situations, regarding surgical treatment, we might perform an atticotomy, which is a limited mastoidectomy, and we would place a ventilation tube
in the eardrum to prevent re-retraction of the pars flacida which often results in normal hearing.
AO/Beck: What about pars tensa cholesteatomas?
Leonetti: The pars tensa cholesteatoma is a posterior-superior retraction cholesteatoma which causes early erosion of the incus and possibly the stapes too, and it also causes otorrhea with an associated conductive hearing loss. The diagnosis is made by microscopic otoscopy and the extent of the cholesteatoma can only be determined by CT. The CT results are then used to determine the surgical treatment plan. So basically, if the cholesteatoma has a limited presentation into the mastoid we might use a canal wall up procedure. However, if the cholesteatoma is extensive, it may require a canal wall down procedure.
AO/Beck: Thanks Dr. Leonetti. The third and final segment of the interview will be next week and that will address mastoidectomy.
Leonetti: Thank you Dr. Beck
CLICK HERE TO REVIEW Part One - Tympanoplasty
