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Carcinoma of External Auditory Canal and Middle Ear

last modified on: Thu, 04/26/2018 - 13:47

  1. GENERAL CONSIDERATIONS
    1. Demographics
      1. Rare cancer, approximately 250 cases per year in the USA.
      2. Usually history of outdoor occupations (increased sun exposure) or history of ear frostbite
      3. Males = females
      4. Associated with chronic otorrhea in approximately two-thirds of cases (possibly related to chronic irritation or chronic exposure to aflatoxin B1)
      5. Cancer may be primary, through direct extension or metastatic
    2. Signs
      1. Canal mass (88%)
      2. Aural drainage (84%)
      3. Periauricular edema (25%)
      4. Facial paralysis (18%)
      5. Neck nodes (8%)
      6. Temporal mass (8%)
    3. Symptoms
      1. Pain (74%)
      2. Hearing loss (62%)
      3. Pruritis (40%)
      4. Bleeding
      5. Headache (18%)
      6. Tinnitus (18%)
      7. Facial numbness (12%)
      8. Vertigo (10%)
      9. Hoarseness (4%)
      10. Facial/Mandibular weakness
    4. Histologic Types of External Auditory Canal (EAC) Cancer
      1. Squamous cell carcinoma (SCC) (86%)
      2. Basal cell carcinoma (BCC) (6%)
      3. Adenoid cystic carcinoma (6%)
      4. Adenocarcinoma (2%)
      5. Melanoma (1%)
      6. Acinic cell (<1%)
      7. Merkel cell (<1%)
    5. Indications
      1. En bloc (as much as feasible) resection of neoplasm involving the EAC
    6. Contraindications (relative)
      1. Dural/brain involvement
      2. Carotid artery involvement
      3. Cavernous sinus involvement
    7. Anatomic Considerations
      1. EAC is cartilaginous (outer two-thirds) and bony (inner one-third).
      2. Cartilaginous EAC offers little barrier to tumor spread (as opposed to the bony EAC, which is a more effective barrier).
      3. Despite the appearance of wide margins of excision, there is a high incidence of local recurrence due to subdermal spread along periosteum and perichondrium.
      4. Fissures of Santorini: dehiscence of cartilage in the lateral EAC allowing direct extension into or from the parotid gland.
      5. Foramen of Huschke: dehiscence of bone in the medial EAC allowing direct extension into or from the TMJ and parotid.
      6. Incidence of occult lymph node metastasis is 10 to 15%.
      7. Lymphatic drainage of the EAC
        1. Anterior: parotid gland and periparotid lymph nodes
        2. Posterior: mastoid lymph nodes and Level V
        3. Inferior: internal jugular lymph nodes
  2. PREOPERATIVE PREPARATION
    1. Evaluation
      1. History, especially previous surgical interventions
      2. Physical exam with emphasis on facial nerve function, evidence of parotid gland extension, and presence of cervical adenopathy
      3. Audiogram to assess for unexpected conductive hearing loss (possible tympanic extension) and degree of sensorineural hearing loss
      4. CT scan (axial temporal bone and neck, with and without contrast) to evaluate for EAC bony canal erosion, extension into the middle ear/mastoid/surrounding soft tissue, or extension into dura/cochlea/petrous apex
      5. MRI with gadolinium is helpful if mastoid/middle ear is opacified (distinguish between tumor and fluid) and to evaluate dural invasion (gadolinium enhancement)
      6. Carotid angiography/balloon test occlusion when intracranial carotid resection is considered
      7. Consultation with neurosurgery (when dural resection considered) and head and neck microvascular surgeon (if free flap reconstruction considered)
      8. Staging
        1. T1: tumor limited to the EAC without bony erosion or soft tissue extension
        2. T2: tumor with limited EAC bony erosion (not full thickness) or limited (<0.5 cm) soft tissue involvement
        3. T3: tumor eroding the osseous EAC (full thickness) with limited (<0.5 cm) soft tissue involvement or tumor involving the middle ear and/or mastoid, or facial paralysis
        4. T4: tumor eroding the cochlea, petrous apex, medial wall of the middle ear, carotid canal, jugular foramen or dura or with extensive (>0.5 cm) soft tissue involvement
    2. Treatment planning
      1. Early stage: complete surgical resection may be possible with direct and relatively limited surgical resection in some carcinomas of the EAC.
      2. Advance Stage
        1. Advanced surgical procedures should be considered.
        2. Multimodality treatment options should be explored (radiation, chemotherapy, etc.)
        3. Depending on particular type of carcinoma and presentation, may consider pre-operative interventional radiology evaluation
    3. Consent
      1. Description: "At minimum, remove your mastoid cells, ear canal, ear drum and hearing bones to encompass the tumor excision. Removal of your hearing and balance organs, facial nerve, parotid gland, and lymph nodes in your neck may also be necessary. Your ear canal will be oversewn, and the mastoid bone will be filled with fat from your abdomen or will require an additional piece of tissue from elsewhere in your body to fill the cavity created behind your ear."
        1. Stress that facial nerve excision and grafting may be required.
        2. Stress that hearing will often be significantly worsened or sacrificed to achieve surgical goals.
      2. Potential complications of treatment
        1. Surgery
          1. Death (3%)
          2. Hemorrhage
          3. Infection
          4. Facial paralysis
          5. Deafness/vertigo
          6. Stroke
        2. Radiotherapy (XRT)
          1. Cartilage necrosis (3 to 10%)
          2. Chronic otitis externa
          3. Serous otitis media
          4. Osteoradionecrosis of the temporal bone
          5. Hearing loss
          6. Encephalomalacia
  3. NURSING CONSIDERATIONS
    1. Room Setup
      1. See Basic Soft Tissue Room Setup
        1. Operating microscope with video unit
        2. Requires "dual setup" for both an otologic procedure and neck procedure with possibility of a craniotomy setup with the neurosurgeons
        3. Basic Soft Tissue Supply pack x 2
        4. NIMS (Neurologic Integrity Monitoring System)
        5. Mayfield headrest
        6. Nerve stimulator control unit and instrument
        7. Sextet suction caddy
    2. Instrumentation and Equipment
      1. Standard
        1. Major Instrument Tray 1, Otolaryngology
        2. Major Instrument Tray 2, Otolaryngology
        3. Fischer Bipolar Instrument Tray
        4. Mastoid Instrument Tray
        5. Bien Otologic Electric Drill Tray
        6. Ear Microsurgery Instrument Tray
        7. Bipolar Forceps Trays
      2. Special
        1. Legend Platinum Drill Tray and burrs
        2. Padgett Dermatome Instrument Tray
        3. Acoustic Neuroma Instrument Tray
        4. Rongeur Tray, Large
        5. Rongeur Tray, Small
        6. Varidyne vacuum suction controller
        7. Malleable ribbon retractors
    3. Medications
      1. 1% lidocaine with 1:100,000 epinephrine for postauricular incision site
      2. 1:100,000 epinephrine for preauricular/periparotid infiltration
      3. Oxycel cotton
      4. Antibiotic ointment
      5. Ringer's injection, 1000 cc bag x 6 for irrigation while drilling
      6. Ringer's irrigation solution, 1000 cc bottles, in warmer x 4
    4. Prep and Drape
      1. Prep
        1. Hair shaven 6 cm posterior to postauricular sulcus
        2. Wide 10% providone iodine prep from head to xiphoid (in case of need for a pectoralis major myocutaneous flap), left lower quadrant of abdomen (for fat harvest), and left leg (for sural nerve graft)
        3. Ipsilateral face prepped to allow intraoperative visualization
        4. Place NIMS (Neurologic Integrity Monitoring System) electrodes into glabella, orbicularis oculi, and orbicularis oris
      2. Drape
        1. Head drape (leave ipsilateral face free of tape)
        2. Towels around head and towels to square off graft site
        3. Surgeon places NIMS needle electrodes
        4. Clear plastic drape over ipsilateral face and neck; split sheet around cranium leaving entire ipsilateral face visible, and drainage bag placed 1 cm behind intended incision
        5. Split sheet around cranium leaving the entire ipsilateral face visible
        6. See Skin graft protocol and Sural Nerve Graft Harvest protocol for specific draping if necessary
    5. Drains and Dressings
      1. Varidyne vacuum suction drains: 7 mm or 10 mm
      2. Adaptic, large and small
      3. Kling wrap, 4 in
      4. Fluffs, 5 pack x 3
    6. Special Considerations
      Position patient securely. Patient should be tucked and padded to allow +/- 30° table rotations.
  4. ANESTHESIA CONSIDERATIONS
    1. Positioning
      1. Head of patient 180° from anesthesia
      2. Double check arms and legs padding to ensure safety
    2. Medications
      1. Cefazolin (Ancef) 1 g IV 1 hour prior to surgical incision
      2. Decadron 12 mg IV at beginning of case if facial nerve manipulation anticipated
      3. Advise the need for "no paralysis" during the case for facial nerve monitoring
      4. Nitrous oxide may be used as no tympanic membrane grafting is typically performed
  5. OPERATIVE PROCEDURE
    1. Sleeve Resection
      1. Small tumors arising from the cartilaginous EAC or involving limited bony EAC are amenable to sleeve resection. This is also the method of choice for biopsying small lesions of the EAC.
      2. 2% lidocaine with 1:20,000 epinephrine is used to anesthetize and vasoconstrict the EAC in a 4-quadrant fashion with the needle inserted at the bony-cartilaginous junction. Additional anesthesia is used through the postauricular sulcus into the mastoid bowl and through the tragus to anesthetize the lateral EAC.
      3. A sickle knife and McCabe flap knife are used to incise normal tissue around the lesion of suspect, ensuring adequate margins of normal tissue. The McCabe flap knife is used to elevate the skin down to bone and cartilage and the specimen is oriented and sent for frozen section analysis.
      4. If margins are clear, a 10/1000-inch split thickness skin graft (STSG) is placed into the defect, followed by Owen's silk circumferentially around the EAC that is held in place with an Ambrose Merocel wick. The sponge is moistened regularly with Cortisporin Otic drops until the packing is removed 1 week later.
      5. If margins are involved, consideration of a lateral temporal bone resection is advisable.
    2. Lateral Temporal Bone Resection
      1. Incisions
        1. Many different incisions can be used. Most often, an incision is placed 4 cm posterior to postauricular sulcus, carried down to superficial temporal fascia superiorly and to sternocleidomastoid muscle inferiorly, identifying and preserving the greater auricular nerve in case nerve grafting later required.
        2. A circumferential incision in the lateral EAC is made to encompass the tumor medially. The skin of the medial (tumor containing) EAC is oversewn to prevent tumor spillage into the operative site.
        3. A circumferential frozen section margin is sent from the lateral EAC incision to ensure tumor clearance.
      2. The skin flap is then dissected anteriorly preserving a thick layer of periosteum over the mastoid cortex and continued until the lateral EAC incision is encountered, allowing the entire auricle to be displaced anteriorly. The skin flap is held in place with 2-0 silk sutures and hemostat clamps to drapes past the midline of the face. Using a Lempert periosteal elevator, an inferiorly based fascio-periosteal flap is then elevated from the mastoid cortex delineated by the temporal line, the spine of Henle, and a line approximately 3 cm posterior to the EAC.
      3. A complete mastoidectomy is then performed, with attention to identification of the
        1. Sigmoid sinus
        2. Middle fossa dura
        3. Sinodural angle
        4. Mastoid antrum
        5. Lateral semicircular canal
        6. Digastric ridge
        7. Epitympanum/zygomatic root
        8. Facial nerve
      4. The posterior EAC wall is left thick to allow manipulation without fracture during later parts of the procedure.
      5. An extended posterior tympanotomy ("facial recess" approach) is then performed and the middle ear is inspected for evidence of tumor penetration. The chorda tympani nerve is sacrificed inferiorly, widely exposing the hypotympanum.
      6. The incus and head of malleus are removed and carefully inspected for evidence of tumor.
      7. The tensor tympani tendon is cut to prevent tethering of the tympanic membrane during later en bloc resection of the tympanic membrane ™ and EAC.
      8. The zygomatic root air cells are then removed in their entirety, opening the air cell tract between the superior portion of the EAC and the middle fossa dura. This dissection should continue until the soft tissue of the temporal mandibular joint (TMJ) is encountered, indicating the anterosuperior limits of resection.
      9. Bone of the inferior tympanic ring is then further drilled anteriorly between the hypotympanum and the lateral EAC until soft tissue of the periparotid fascia is encountered, indicating the anteroinferior limits of resection.
      10. The final bony attachment lateral to the eustachian tube orifice can be liberated either with a curved osteotome through the posterior tympanotomy (remembering that the internal carotid is only millimeters anteriorly) or by gentle manual rocking of the bony EAC until a fracture allows removal of the specimen from the TMJ capsule. When the anterior EAC shows evidence of bony erosion, a cuff of parotid gland and condylar capsule +/- condyle should be resected.
      11. The medial aspect of the specimen is carefully analyzed under the operating microscope to ensure no tumor extension medial to the tympanic membrane. Frozen sections are sent from the middle ear mucosa to rule out subclinical tumor extension (see Subtotal temporal bone resection below).
      12. By extending the postauricular skin flap more anteriorly, a supraneural (lateral) parotidectomy is then performed to gain both additional surgical margins and to address intraparotid lymph nodes (see Nursing Teaching for Parotidectomy protocol).
      13. By extending the postauricular skins flap more inferiorly, cervical lymph nodes are removed.
        1. If the physical examination and the CT/MRI are without evidence of nodal disease, an elective lymphadenectomy may be considered to definitively stage the neck in expectation that pN0 stage will allow for single modality treatment with surgery only. If postoperative irradiation is to be administered based on findings at the primary site, there is no need for an elective lymphadenectomy. Potential occult metastases to the neck will be addressed by the radiotherapy in this case.
        2. If there is evidence of nodal disease, a comprehensive neck dissection is performed (see Cervical lymphadenectomy protocol).
      14. The lateral EAC is then everted and oversewn (resecting cartilage of the conchal bowl to achieve additional skin advancement) with 4-0 vicryl.
      15. Abdominal fat is harvested from a 5 cm incision left of the umbilicus, with care taken to remove the fat en bloc using Metzenbaum scissors (electrocautery excision leads to increased fat necrosis). The wound is closed in layers to obliterate the defect over a quarter-inch Penrose drain. The skin in reapproximated with interrupted 4-0 nylon and a pressure dressing applied with fluffs and Elastoplast tape to prevent postoperative hematoma formation.
      16. The eustachian tube is now obliterated by abrading the mucosa with a Stapes curette or Rosen knife and packing the orifice with temporalis fascia, bone wax, and temporalis muscle.
      17. Fat is cut to fill the mastoid/EAC defect and the fascio-periosteal flap interposed between the fat and the oversewn EAC, the later secured to the undersurface of the skin flap using 3-0 vicryl.
      18. The postauricular skin flap is closed in a layered fashion with 3-0 vicryl over a passive (Penrose) drain. When a parotidectomy and cervical lymphadenectomy is performed, closed drainage systems using a #10 fully perforated Jackson-Pratt Varidyne drainage system at 125 mm Hg is preferred. 3-0 interrupted nylons are used to close the skin, followed by a snug mastoid dressing.
    3. Subtotal Temporal Bone Resection (STBR)
      1. Steps A-K are performed as above as for a LTBR. If tumor is noted in the middle ear, mastoid, hypotympanum, or otic capsule, a STBR is performed. En bloc resection does not appear to be necessary, as "piecemeal" resections beyond a LTBR have shown similar survival rates with less morbidity when compared with en bloc resection for advanced cancer of the temporal bone.
      2. A "translabyrinthine" approach (see Acoustic Neuromas excision) begins with removal of bone over and behind the sigmoid sinus, the jugular bulb, and the posterior fossa plate.
      3. The internal auditory canal (IAC) is skeletonized, overlying bone removed, and the vestibular and cochlear nerves are transected to allow isolation the facial nerve. The facial nerve is then skeletonized, overlying bone removed from the IAC to the stylomastoid foramen, the GSPN liberated from the geniculate ganglion, and the nerve transposed back into the posterior mastoid cavity. Tumor involving the facial nerve requires excision with frozen section control of margins and an interposition graft using the greater auricular or sural nerve, carried out with 4, interrupted 9-0 nylon epineurial sutures.
      4. The bone of the fallopian canal is then removed and extended inferiorly to remove the mastoid tip and digastric muscle.
      5. Cochlear otic capsule bone is drilled with care taken anteriorly to avoid injury to the internal carotid artery.
      6. Tumor extension into the jugular foramen requires isolation of the internal cartilage artery (ICA), internal jugular vein (IJV), and lower cranial nerves from the jugular foramen. The IJV is ligated in the neck and the sigmoid sinus ligated in the mastoid cavity and intervening vein resected. Tumor extension into the lumen of the IJV warrants consideration of resection and frozen section control of the nerves of the jugular foramen (cranial nerves 9, 10, and 11).
      7. Tumor extension into the dura denotes a poor prognosis, with clearance of dural tumor showing no effect on overall survival. Dural resection should be accomplished in conjunction with a neurosurgeon.
      8. Tumor extension into the infratemporal fossa is often indicated by involvement of the protympanum and requires transposition of the internal carotid artery and resection of tissue around the eustachian tube (see Infratemporal fossa approach).
      9. On completion of tumor resection with frozen section control, the lateral skull defect is reconstructed with a vascularized soft tissue flap (temporalis, trapezius, pectoralis, or free flap).
      10. A STSG is placed in the conchal bowl defect, atop the transposed myofascial flap. A layered closure with 3-0 vicryl over a passive drain is followed by an interrupted 3-0 nylon closure at the skin. A mastoid dressing is placed.
    4. Radical Temporal Bone Resection (RTBR)
      1. A RTBR is typically performed when tumor extension is identified in the petrous apex. Few indications exist, however, to justify the added morbidity and mortality over a STBR. Combined neurosurgical and neurotologic skills are necessary to complete this procedure.
      2. Preoperative balloon test occlusion with permanent ICA occlusion if the patient remains neurologically asymptomatic.
      3. The patient's head is placed on a Mayfield headrest, a lumbar drain is placed, and tracheotomy is performed if vagus nerve sacrifice is planned. The prep and drape is performed as per LTBR.
      4. A postauricular incision 4 cm behind the postauricular sulcus is performed as per LTBR, extending inferiorly into the neck to allow access the cervical lymph nodes and the jugular foramen and anteriorly exposing the zygomatic arch and ascending mandibular ramus. A cervical lymphadenectomy (Levels I through V) is performed if evidence of adenopathy exists, followed by identification and isolation of the IJV, ICA, and lower cranial nerves at the skull base.
      5. A lateral parotidectomy is next performed followed by osteotomies of the zygomatic arch and mandibular condyle using a Striker oscillating saw. The facial nerve is identified at the stylomastoid foramen, resected cleared with a frozen section, and tagged for later interposition grafting.
      6. A translabyrinthine approach (see Acoustic Neuromas excision protocol) is used to remove bone overlying the sigmoid sinus and jugular bulb as well as that overlying the middle and posterior fossa dura. Brain retractors are placed to displace the posterior and middle fossa dura. The ICA and IJV are ligated in the neck below the jugular foramen. The transverse sinus and superior petrosal sinuses are ligated in the mastoid cavity. The lower cranial nerves are preserved until oncologic reasons dictate the need for resection. The facial nerve is transected in the IAC, evaluated with a frozen section, and tagged for later interposition grafting.
      7. The petrous apex is then freed from the clivus with anteriorly directed drill cuts until the intratemporal carotid artery is identified and clipped. This allows the temporal bone petrous apex to be removed.
      8. Dura underlying the area of tumor is then resected and reconstructed with fascia lata.
      9. Abdominal fat is placed into the operative defect, and watertight closure with a regional or free myofascial flap is performed (see STBR). No drains are used. The lumbar drain is kept in place postoperatively.
      10. A feeding tube is place if lower cranial nerves are resected.
  6. INDICATIONS FOR ELECTIVE CERVICAL LYMPHADENECTOMY
    1. Any N(+) neck should undergo a comprehensive neck dissection and parotidectomy.
    2. 10 to 15% incidence of positive lymph nodes in the N0 neck. (If irradiation is not planned, an elective lymphadenectomy is done to identify the 10 to 15% who will need postoperative radiotherapy based on confirmed occult metastases).
    3. Metastases are most commonly found in upper cervical region (13%) and parotid (11%).
    4. Lymph node metastasis denotes poor prognosis, with increased doubled incidence of local recurrence.
    5. Therefore, lateral parotidectomy and Levels II through V selective lymphadenectomy indicated for T1 and T2 N EAC SCC, to obviate the need for postoperative radiotherapy if resection margins are negative and lymph nodes without evidence of metastasis.
  7. INDICATIONS FOR POSTOPERATIVE RADIOTHERAPY
    1. Following a LTBR with negative surgical margins, postoperative XRT has not been shown to improve survival in EAC SCC confined to the EAC (ie, T1/T2 lesions).
    2. Postoperative XRT significantly improves survival in T3/T4 lesions excised with negative margins.
    3. Postoperative XRT has shown no survival benefit for resections with positive margins, though possible effects on palliation or delayed recurrence should be considered.
  8. POSTOPERATIVE CARE
    1. Aggressive eye lubrication is critical if facial palsy is present postoperatively, including Lacri-Lube and a moisture chamber at night and artificial tears throughout the day.
    2. The postoperative care required for a LTBR is similar to that of a mastoidectomy, requiring a secure mastoid dressing until postoperative day 5. The Penrose drain is removed from the postauricular wound on postoperative day 1 or 2. The abdominal Penrose drain is removed the first postoperative morning, replaced with a new Elastoplast pressure dressing. Neck and parotid bed suction drains remain in place until -30 cc of drainage is present over a 24-hour period.
    3. Bolsters on STSGs are removed on postoperative day 7 along with sutures. Oral antibiotics are continued until the bolster is removed.
    4. Patients with dural resection and repair are monitored in the ICU for 24 to 48 hours, with lumbar drainage managed by the neurosurgical team.
    5. Tube feeding and NPO status is continued if lower cranial nerve resection is performed, with early evaluation by speech pathology to diminish postoperative aspiration risk.
    6. Early mobilization of the mandible is begun if condylectomy is performed to minimize postoperative ankylosis.
  9. SUGGESTED READING
    1. Arriaga M, Curtin H, et al. Staging proposal for external auditory meatus carcinoma based on preoperative clinical examination and computed tomography findings. Ann Otol Rhinol Laryngol. 1990;99(9 Pt 1): 714-721.
    2. Arriaga M, Hirsch BE, et al. Squamous cell carcinoma of the external auditory meatus (canal). Otolaryngol Head Neck Surg. 1989;101:330-337.
    3. Austin JR, Stewart KL, et al. Squamous cell carcinoma of the external auditory canal. Therapeutic prognosis based on a proposed staging system. Arch Otolaryngol Head Neck Surg. 1994;120:1228-1232.
    4. Conley J, Schuller DE. Malignancies of the ear. Laryngoscope. 1976;86:1147-1163.
    5. Gidley PW, Managing malignancies of the external auditory canal. Expert Rev Anticancer Ther. 2009 Sep;9(9):1277-82.
    6. Goodwin WJ, Jesse RH. Malignant neoplasms of the external auditory canal and temporal bone. Arch Otolaryngol. 1980;106:675-679.
    7. Hahn SS, Kim JA, et al. Carcinoma of the middle ear and external auditory canal. Int J Radiat Oncol, Biol, Physics. 1983;9:1003-1007.
    8. Kinney SE, Wood BG. Malignancies of the external ear canal and temporal bone: surgical techniques and results. Laryngoscope. 1987;97:158-164.
    9. Kinney SE. Squamous cell carcinoma of the external auditory canal. Am J Otol. 1989;10:111-116.
    10. Lesser RW, Spector GJ, et al. Malignant tumors of the middle ear and external auditory canal: a 20-year review. Otolaryngol Head Neck Surg. 1987;96:43-47.
      ##Litofsky NS, Smith TW, et al. Merkel cell carcinoma of the external auditory canal invading the intracranial compartment. Am J of Otolaryngol 1998; 19;5:330 -334
    11. Lewis JS. Temporal bone resection. Review of 100 cases. Arch Otolaryngol. 1975;101:23-25.
    12. Medina JE, Park AO, et al. Lateral temporal bone resections. Am J Surg. . 1990;160: 427-433.
    13. Nadol JB Jr, Schuknecht HF. Obliteration of the mastoid in the treatment of tumors of the temporal bone. Ann Otol Rhinol Laryngol. 1984;93(1 Pt 1):6-12.
    14. Prasad S, Janecka IP. Efficacy of surgical treatments for squamous cell carcinoma of the temporal bone: a literature review. Otolaryngol Head Neck Surg. 1994;110:270-280.
    15. Prasad M., Kraus D. Acinic cell carcinoma of the parotid gland presenting as an external auditory canal mass. Head Neck  2004; 26:85-88.
    16. Sataloff RT, Myers DL, et al. Total temporal bone resection for squamous cell carcinoma. Otolaryngol Head Neck Surg. 1987;96:4-14.
    17. Shih L, Crabtree JA. Carcinoma of the external auditory canal: an update. Laryngoscope. 1990;100:1215-1218.
    18. Shotton JC, Sergeant RJ, et al. Lateral temporal bone resection for extensive pinnal malignancy. Has anything changed in forty years? J Laryngol Otol. 1993;107:697-702.
    19. Testa JR, Fukuda Y, et al. Prognostic factors in carcinoma of the external auditory canal. Arch Otolaryngol Head Neck Surg. 1997;123:720-724.
    20. Tiwari R, Feenstra L, et al. Temporal bone resections for carcinoma of the middle ear and the external ear canal. Am J Surg. 1992;164:648-650.
    21. Wang CC. Radiation therapy in the management of carcinoma of the external auditory canal, middle ear, or mastoid. Radiology. 1975;116: 713-715.