History

Fact Explanation
Introduction to the disease Cholesteatoma of external ear is a rare condition.Estimated incidence is about 1.2 per 1,000 among otological patients. disease may presents itself by an accumulation of epithelial debris in the ear canal.Most useful finding confirming an external ear canal cholesteatoma (EECC ) and differentiating it from keratosis obturans is focal osteonecrosis or the sequestration of bone lacking an epithelial covering.Based on pathogenetic theories there are classifications of EECC. One such classification is 1) primary EECC, 2) secondary EECC, and 3) cholesteatoma associated with congenital atresia of the ear canal.[1].
Otorrhea Even some patients remain asymptomatic, one of the common presenting symptom EECC is otorrhea or so called ear discharge.[1].
Otalgia It is also a common symptom. It is more vague or mild discomfort. But it also can be a chronic dull pain or a severe pain in some cases.[1]
Fullnes It is a vague symptom. It is a subjective feeling in the ear canal which is neither otalgia nor occlusion.[1].
Occlusion Found in some patients. It is a subjective feeling of having the ear canal occluded and frequently accompanied with conductive hearing loss.[1].
Tinnitus Tinnitus is ringing or humming of one or both ears without any stimulus. It is a manifestation of cholesteatoma of external ear.[2],[1].
Hearing loss Some may present with conductive hearing loss. Most of the time it is due to occlusion of ear canal due to accumulation of debris. It is relieved following removal of debris.[1]
Vertigo Experienced by some patients. Extension of bony erosion with subsequent invasion of the adjacent structures of the temporal bone may leads to vertigo as well as facial nerve palsy.[1],[3].
Disruption of balance Disruption of balance in the presence of a cholesteatoma raises the possibility of cholesteatoma is eroding the balance organs, which form part of the inner ear such as labyrinth.[1],[4].
Mastoiditis and meningitis If left untreated,cholesteatoma will either grow or expand. It may further destructs the ear structures and leads to development of infections. In severe cases it may results mastoiditis or invasion of internal structures of the brain may result meningitis which may need urgent treatments.[5].
History of surgery,recurrent inflammation and trauma Secondary EECC is found to be related to a variety of conditions mainly postoperative. Some of the other conditions are postinflammatory, recurrent inflammation, posttraumatic stenosis as well as atresia with ear canal obstruction.[1].
History of radiation therapy Radiation therapy incorporating the ear canal also found to be leads to EECC.[1].
Congenital abnormalities of the ear canal Studies found that cholesteatoma is also associated with congenital atresia of the ear canal.[1].
History of smoking Smoking also a contributory factor for this disease.Smoking induce hypoxia as well as tissue ischemia may predispose to above condition.[1].
References
  1. OWEN HH, ROSBORG J, GAIHEDE M. Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases BMC Ear Nose Throat Disord [online] :16 [viewed 09 October 2014] Available from: doi:10.1186/1472-6815-6-16
  2. POLAT C, BAYKARA M, ERGEN B. Evaluation of Internal Auditory Canal Structures in Tinnitus of Unknown Origin Clin Exp Otorhinolaryngol [online] 2014 Sep, 7(3):160-164 [viewed 09 October 2014] Available from: doi:10.3342/ceo.2014.7.3.160
  3. TROJANOWSKA A, DROP A, TROJANOWSKI P, ROSIńSKA-BOGUSIEWICZ K, KLATKA J, BOBEK-BILLEWICZ B. External and middle ear diseases: radiological diagnosis based on clinical signs and symptoms Insights Imaging [online] , 3(1):33-48 [viewed 09 October 2014] Available from: doi:10.1007/s13244-011-0126-z
  4. SHIN SH, SHIM JH, LEE HK. Classification of External Auditory Canal Cholesteatoma by Computed Tomography Clin Exp Otorhinolaryngol [online] 2010 Mar, 3(1):24-26 [viewed 10 October 2014] Available from: doi:10.3342/ceo.2010.3.1.24
  5. HOLT JJ. Cholesteatoma and Otosclerosis: Two slowly progressive causes of hearing loss treatable through corrective surgery Clin Med Res [online] 2003 Apr, 1(2):151-154 [viewed 11 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069039

Examination

Fact Explanation
Ear discharge Initial inspection may reveals ear canal full of discharge. Accumulation of debris can be seen.[1]. A foul smelling discharge which contain blood is detected in case of associated infection.[2].
Swelling behind the ear Even though infective features can be seen seldom, some may present with pain and swelling behind the ear which may detect on examination, indicative of ongoing infection.[2].
Bony erosion Extension of bony erosion is seen in some cases. Invasion of the adjacent structures of the temporal bone such as mastoid bone, middle ear cavity as well as exposure of the temporomandibular joint can be identified. [1].
Facial nerve palsy A rare presentation. Dehiscence of the facial nerve due to extension of bony erosion may leads to this manifestation.[1].
Hearing loss Examination of cranial nerves may reveals conductive hearing loss either due to accumulation of debris or ossicular disruption.[1].
References
  1. OWEN HH, ROSBORG J, GAIHEDE M. Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases BMC Ear Nose Throat Disord [online] :16 [viewed 09 October 2014] Available from: doi:10.1186/1472-6815-6-16
  2. HOLT JJ. Cholesteatoma and Otosclerosis: Two slowly progressive causes of hearing loss treatable through corrective surgery Clin Med Res [online] 2003 Apr, 1(2):151-154 [viewed 11 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069039

Differential Diagnoses

Fact Explanation
Atresia of the external auditory canal It is a birth defect, and accompanied by auricle malformation. They may present with conductive hearing loss because sound cannot reach to the tympanic membrane. Microtia or the malformed auricle as well as significantly narrowed EAC can be found in examination.[1],[2].
Necrotizing external otitis It is an infection involving primarily bones and cartilaginous external auditory canal and adjacent structures. It is a rare complication of external otitis. Immunocompromised persons can commonly get involved specially elderly patients with diabetes mellitus. Either self-inflicted or iatrogenic trauma to the external auditory canal may leads to initiation of the disease. Severe otalgia that worsens at night as well as otorrhea are the common clinical symptoms. And some may present with conductive hearing loss. Otoscopic examination will review granulation tissue in the external auditory canal commonly found at the bony-cartilaginous junction.[1].
EAC squamous cell carcinoma It is an aggressive neoplasm in the EAC. It spreads along vascular and neural pathways and also invading adjacent structures. Commonly found in temporal bone in 5th and 6th decades of life.Otorrhea, otalgia, hearing loss as well as bleeding are the common presentations.[1].
EAC Exostoses It is a benign appearing bony protuberances. They are arising from the osseous portions of EAC. Prolonged, repetitive exposure to cold water may leads to development of above disease. The common clinical manifestations are conductive hearing loss , recurrent episodes of external otitis and otalgia.[1].
EAC medial canal fibrosis It is a post-inflammatory, acquired atresia of EAC. Formation of fibrous tissue,overlying lateral surface of tympanic membrane is characteristic. It is bilateral around 60% of cases.History of chronic otitis can be identified. Affected individuals may present with conductive hearing loss and otorrhea.[1].
Ear Wax (Cerumen) Even though accumulation of wax in the EAC is a physiological process it becomes pathological only when it produces either symptoms or prevents assessment of the ear canal and the audiovestibular system, or both. It often diagnose clinically and hypodense lesion filling the EAC can be demonstrated in HRCT. The findings which confirm the diagnosis include fat attenuation within the lesion and the presence of a rim of air around the lesion.[2].
Keratosis obturans They may present with acute severe ear pain. some may present with hearing impairment. Inflammation of the ear canal skin as well as tympanic membrane can be seen.Accumulation of epithelial debris in the ear canal can be identified. However most useful finding to differentiate EECC from keratosis obturans is focal osteonecrosis or sequestration of bone lacking an epithelial covering which found in EECC.[3].
Malignant Otitis Externa (MOE) It is a misnomer because it is not a malignant condition. However it gained that term due to aggressive clinical behavior as well as high mortality associated with it.It is usefull to differentiate EACC and Malignant Otitis Externa. Even though EACC is a slowly progressing chronic disease with well localized, and a soft tissue density eroding one of the walls of the EAC, MOE is rapidly progressive diffuse process involving most of the EAC.[2].
References
  1. TROJANOWSKA A, DROP A, TROJANOWSKI P, ROSIńSKA-BOGUSIEWICZ K, KLATKA J, BOBEK-BILLEWICZ B. External and middle ear diseases: radiological diagnosis based on clinical signs and symptoms Insights Imaging [online] , 3(1):33-48 [viewed 09 October 2014] Available from: doi:10.1007/s13244-011-0126-z
  2. CHATRA PS. Lesions in the external auditory canal Indian J Radiol Imaging [online] 2011, 21(4):274-278 [viewed 09 October 2014] Available from: doi:10.4103/0971-3026.90687
  3. OWEN HH, ROSBORG J, GAIHEDE M. Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases BMC Ear Nose Throat Disord [online] :16 [viewed 09 October 2014] Available from: doi:10.1186/1472-6815-6-16

Investigations - for Diagnosis

Fact Explanation
CT scan Diagnosis is mainly clinical with the help of imaging, such as CT. Non contrast CT and HRCT also used. It will show hypodense areas in EAC and involvement of tympanic membrane, mastoid air cells as well extension to the middle ear structures. Not only diagnosis but also it may helpful to exclude most of other conditions mentioned under differential diagnosis.[1].
MRI Diffusion MRI imaging is found to be helped in tricky situations. EACC will show prompt diffusion restriction where it may helpful to differentiate from malignancy because malignant otitis externa does not show restriction on diffusion.[1].
Plain X ray Even it may play a minimum role due to the use of advance imaging such as CT and MRI, plain x ray may helpful in conditions where the disease associated with skull fractures.[2].
Audiometry Performed for hearing assessment since patients are complained of hearing loss.[2],[3].
FBC Performed as a basic investigation to detect ongoing infection.[2].
ESR Also can performed as a baseline investigation in suspected cases of associated infection.[2].
References
  1. CHATRA PS. Lesions in the external auditory canal Indian J Radiol Imaging [online] 2011, 21(4):274-278 [viewed 10 October 2014] Available from: doi:10.4103/0971-3026.90687
  2. OWEN HH, ROSBORG J, GAIHEDE M. Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases BMC Ear Nose Throat Disord [online] :16 [viewed 10 October 2014] Available from: doi:10.1186/1472-6815-6-16
  3. KHOYRATTY F, SWEED A, DOUGLAS S, MAGDY T. Osteoma with cholesteatoma of the external auditory canal: neck manifestation of this rare association J Surg Case Rep [online] 2013 Jun, 2013(6):rjt048 [viewed 10 October 2014] Available from: doi:10.1093/jscr/rjt048

Investigations - Fitness for Management

Fact Explanation
Full blood count (FBC) Carried out to detect Hb and platelet levels. It is performed to assess the fitness for surgery.[1],[2].
Fasting blood sugar (FBS) It is also performed to assess the fitness before surgery since it is done under GA to assess the blood glucose level .[1],[2].
ESR Also perform as a routine investigation since recurrent inflammation and post inflammatory conditions act as an etiological factors for the disease. [1].
CT and MRI Useful to assessment of involved other adjacent structures in ear such as middle ear, mastoid cavity, labyrinth, facial nerve and ossicles. It may helpful in deciding the type of surgery.[3].
References
  1. OWEN HH, ROSBORG J, GAIHEDE M. Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases BMC Ear Nose Throat Disord [online] :16 [viewed 10 October 2014] Available from: doi:10.1186/1472-6815-6-16
  2. HOLT JJ. Cholesteatoma and Otosclerosis: Two slowly progressive causes of hearing loss treatable through corrective surgery Clin Med Res [online] 2003 Apr, 1(2):151-154 [viewed 10 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069039
  3. SHIN SH, SHIM JH, LEE HK. Classification of External Auditory Canal Cholesteatoma by Computed Tomography Clin Exp Otorhinolaryngol [online] 2010 Mar, 3(1):24-26 [viewed 10 October 2014] Available from: doi:10.3342/ceo.2010.3.1.24

Investigations - Screening/Staging

Fact Explanation
CT scan Classification of EAC cholesteatoma mainly depend on CT scan and clinical findings.Stage I cholesteatoma is found to be limited to the EAC.Stage II cholesteatoma involves the tympanic membrane and also the middle ear. If EAC involves the mastoid air cells it is called stage III.Lesion extends beyond the temporal bone is seen in In stage IV cholestetoma.[1],[2].
References
  1. CHATRA PS. Lesions in the external auditory canal Indian J Radiol Imaging [online] 2011, 21(4):274-278 [viewed 10 October 2014] Available from: doi:10.4103/0971-3026.90687
  2. SHIN SH, SHIM JH, LEE HK. Classification of External Auditory Canal Cholesteatoma by Computed Tomography Clin Exp Otorhinolaryngol [online] 2010 Mar, 3(1):24-26 [viewed 10 October 2014] Available from: doi:10.3342/ceo.2010.3.1.24

Management - General Measures

Fact Explanation
Patient education Patient / family should be educate regarding the disease, and what consequences resulted in if left untreated. Then doctor should explain the available surgical methods to them. After that should inform the possible surgical complications and take written consent for the surgery. Those possible complications are hearing loss which can be complete and permanent,Dizziness which may resolves within a day of surgery,partial or complete facial nerve paralysis, Tinnitus and taste abnormalities. And also possible complications of anesthesia since this is performed under GA, bleeding, infection and other more remote operative problems should be informed to the patient.[1].
References
  1. HOLT JJ. Cholesteatoma and Otosclerosis: Two slowly progressive causes of hearing loss treatable through corrective surgery Clin Med Res [online] 2003 Apr, 1(2):151-154 [viewed 10 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069039

Management - Specific Treatments

Fact Explanation
Local care and canaloplasty The main goal of treatment for EACC is preservation of the normal external auditory canal skin as well as surgical removal of the cholesteatoma and necrotic bone tissue thereby prevent disease progression and bone destruction. Degree of bone necrosis , bony erosion as well as the surgeon's judgment may play a role in deciding limit of surgical removal. Treatments depend on the stage of disease.Local care or canaloplasty can be consider in management of stage I disease.[1].
Canaloplasty and tympanoplasty Canaloplasty and tympanoplasty are used in management of stage II disease.[1]. Tympanoplasty involves the tympanum. The tympanum is the area of the ear which is behind the ear drum where the ossicles are located.[2].
Canaloplasty and mastoidectomy Canaloplasty and tympanoplasty are used in management of stage II disease.[1]. Tympanoplasty involves the tympanum. The tympanum is the area of the ear which is behind the ear drum where the ossicles are located.[2].
Removal of cholesteatoma via middle fossa approach or the transzygomatic approach In case of lesion progresses beyond the temporal bone where we called stage IV, cholesteatoma have to be removed via various approaches. Some of those methods are the middle fossa approach or the transzygomatic approach.[1] However there are two basic surgical approaches to the ear. They are transcanal where performed through the ear canal and Postauricular where the surgery is performed by making an incision behind the ear then moving the ear forward to allow exposure of the mastoid and middle ear.[2].
Ossiculoplasty It is performed to repair or reconstruct the ossicles to improve hearing. Several techniques as well as prostheses can be used for the reconstruction.[2].
References
  1. SHIN SH, SHIM JH, LEE HK. Classification of External Auditory Canal Cholesteatoma by Computed Tomography Clin Exp Otorhinolaryngol [online] 2010 Mar, 3(1):24-26 [viewed 10 October 2014] Available from: doi:10.3342/ceo.2010.3.1.24
  2. HOLT JJ. Cholesteatoma and Otosclerosis: Two slowly progressive causes of hearing loss treatable through corrective surgery Clin Med Res [online] 2003 Apr, 1(2):151-154 [viewed 10 October 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069039