DISEASES OF THE EXTERNAL EAR 1.2 (AB) Flashcards
What are exostoses?
“Benign bony outgrowths in the periosteum.”
What is the typical structure of exostoses?
“They demonstrate concentric lamellar bony organization.”
What are common symptoms of exostoses?
“Often asymptomatic but may cause conductive hearing loss if obstructive.”
What complications can arise from untreated exostoses?
“Infection and otalgia.”
What is the treatment for symptomatic exostoses?
“Excision using a diamond burr.”
What severe complication can arise from exostoses?
“Potential perforation of the tympanic membrane.”
What is squamous cell carcinoma (SCC)?
“A malignant tumor that can arise from the epithelium and adnexa.”
What percentage of external auditory canal tumors are SCC?
“20%.”
What is the second most common skin cancer?
“Squamous cell carcinoma.”
What percentage of malignant tumors of the auricle and EAC are SCC?
“80%.”
Does SCC commonly metastasize?
“No. metastasis is uncommon.”
What is the treatment for small SCC tumors?
“Local wide excision.”
What is the treatment for large SCC tumors?
“Whole auricle is sacrificed.”
What is the treatment for SCC with lymph node involvement?
“Radical en bloc resection.”
What is a major etiological factor for SCC?
“Excessive UV exposure.e.g.sunbathing.”
What is basal cell carcinoma (BCC)?
“A malignancy caused by the proliferation of basal cells in the epithelium.”
How does BCC compare to SCC in terms of aggression?
“BCC is locally aggressive and more invasive than SCC.”
Does BCC metastasize?
“No. but it is locally aggressive and can invade cartilage and bone.”
What is the primary risk factor for BCC?
“Overexposure to sunlight. particularly in outdoor workers.”
How fast can a small BCC nodule grow?
“It can double in size within a week and become a large necrotic mass in a year.”
What is the treatment for BCC?
“Wide surgical excision similar to SCC.”
What is a malignant melanoma?
“An extremely rare malignancy developing from a pigmented nevus.”
What are signs of malignant melanoma?
“Sudden elevation. ulceration and bleeding of a darkly pigmented nevus.”
What is the treatment for malignant melanoma?
“Wide excision.”
What is adenoid cystic carcinoma?
“A malignancy arising from ceruminous glands. also called cylindroma.”
What are the clinical features of adenoid cystic carcinoma?
“Yellowish smooth masses with numerous dilated vessels.”
What is the primary treatment for adenoid cystic carcinoma?
“Surgical excision.”
What is an adenoma?
“A rare tumor originating from sebaceous glands in the fibrocartilaginous EAC.”
What are the symptoms of an adenoma?
“Small. soft. painful swelling at the meatal entrance.”
When does an adenoma become symptomatic?
“When it grows large enough to cause obstruction.”
What is the treatment for adenoma?
“Complete excision with electrocautery of the tumor bed.”
What is aural atresia?
“A congenital absence or severe narrowing of the external auditory canal (EAC).”
How common is aural atresia?
“Occurs in 1 in 10 000 live births.”
What embryonic structures are involved in aural atresia?
“1st and 2nd branchial arches and 1st branchial cleft.”
How often is aural atresia bilateral?
“One-third of cases are bilateral.”
What complication can EAC stenosis lead to?
“Canal cholesteatoma.”
What are Group I external ear anomalies?
“Minor malformations with a mostly normal auricle and occasional EAC hypoplasia.”
What are Group II external ear anomalies?
“Moderate malformations like microtia and EAC hypoplasia or aplasia.”
What are Group III external ear anomalies?
“Severe malformations. including absent auricle and ossicles.”
What are first branchial cleft anomalies?
“Congenital anomalies due to failure of normal obliteration of the first branchial cleft.”
What types of abnormalities can first branchial cleft anomalies present as?
“Cysts. sinuses or fistulas.”
What is Type I first branchial cleft anomaly?
“A duplication of the membranous EAC from ectoderm of the 1st branchial cleft.”
What is Type II first branchial cleft anomaly?
“Contains ectoderm and mesoderm elements from the 1st and 2nd branchial arches.”
Where are Type II first branchial cleft anomalies typically located?
“Anterolateral neck. anterior to the SCM. often coursing over the mandible and through the parotid.”
What is the common presentation of first branchial cleft anomalies?
“Asymptomatic until infection occurs.”
What is the treatment for recurrent first branchial cleft anomalies?
“Complete surgical excision with facial nerve preservation.”
