Preauricular Lesion

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Preauricular Lesion

• John Francis McGuire III, MD, MBA

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Case Report

• 14 year old male presents to ER with a five day
  history of left otalgia and auricular swelling.
  The patient gives a history of swimming in the
  river a week prior to the onset of symptoms. He
  saw his PCP 3 days ago and was prescribed Cipro
  Otic drops, but symptoms progressed.

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History

• PMHx allergic rhinitis
• PSHx skin lesion removed from back at 9 months
  old
• Meds Claritin
• Allergies NKDA
• Immz UTD

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Physical Exam

• Alert, Afebrile, EOMI, CN7 intact
• Left auricle slightly proptotic, preauricular
  swelling and periauricular cellulitis, tenderness
  to palpation anterior to tragus and with
  manipulation of the auricle approximate 2x2 cm
  firm mass 1 cm anterior to tragus edematous EAC,
  TM intact and mobile with no evidence of
  effusion. Right EAC and TM within normal limits.
  TF AgtB Bilateral, Weber .
• Boggy nasal mucosa with turbinate hypertrophy.
• O/P clear, 2 tonsils, mild trismus.
• Neck no adenopathy or masses
• CP exam WNL

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Work Up

• Labs
• CBC, Chem 7, UA
• cultures
• Imaging
• CT
• MRI
• US

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Differential for Preauricular Lesion

• V hemangioma, AVM, superficial temporal artery
  aneurism, lymphangioma
• I otitis externa, insect bite, acne, acute
  parotitis, actinomycoisis, cat-scratch disease,
  TB/NTB, furunculosis, synovial chondromatosis of
  the TMJ, facial/buccal cellulitis, orbital
  adenexa infections (Perinauds syndromepreauricul
  ar lymph node enlargement on the same side as
  conjunctivitis) any infection of the temporal
  scalp, upper face, and anterior pinna
• T foriengn body, piercing injury
• A Sjogrens syndrome, sarcoidosis, wegeners
  granulmatosis (unlikely)
• M unlikely
• I auricular chondritis, seborrheic dermatitis,
  Kimuras disease allergic otitis externa
• N parotid neoplasm, lymphoma, mandibular
  osteoma, auricular chondroma, preauricular
  pilomitricoma (benign hair follicle neoplasm),
  BCC/SCC, orbital tumors
• C branchial cleft cyst, preauricular sinus,
  keratosis obturans (faulty migration of canal
  epithelium, ass with chronic sinusitis and
  bronchiectasis)

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Diagnosis

• 1st Brancial cleft cyst

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Anatomy of Auricle
Helix Tuberculum Helix Crus helicis Antehelix
Antehelix Crus antehelicis Crus antehelicis
Fossa triangularis Scapha Tragus Incisura
anterior Antitragus Incisura intertragica
Sulcus posterior Lobulus Cymba conhae Cavum
conhae External Meatus
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EAC Anatomy

• General
• Approximately 2.5 cm long, but because TM is
  oblique, anterointerior canal is 6 mm
  (longer/shorter) than the posterosuperior canal
• Medial 2/3 bony, lateral 1/3 cartilaginous
  junction isthmus and is narrowest part of the
  canal
• Only cartilaginous EAC has subcutaneous adnexal
  structures (hair, glands, called apopilosebacous
  units)
• Blood Supply multiple. Deep auricular artery
  enters the canal at the bony cartilaginous
  junction and sends a group of vessels medially
  along the (?) canal wall.
• Lymphatics anterior to parotid, posterior to
  postauricular and superficial cervical nodes.
• Nervous CN 5 (ATant/sup),7, 9, 10 (Arnolds),
  and cervical plexus overlap responsible for
  referred otalgia, ear-cough reflex
• Fissures of Santorini Two or three
  vertically-oriented fissures in the
  anteroinferior aspect of the cartilaginous canal.
• Foremen of Huschke a passage formed by union of
  the tubercles of the tympanic ring it normally
  becomes ossified and disappears during childhood.
  Persists in 7 of the population. (position? A
  anterior)

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Auricular Embryology

• Most embryologic studies of the ear focus on the
  development of the 6 ear hillocks. These hillocks
  appear around the fundus of the first branchial
  groove by 38 days of gestation. As the groove
  closes and the first and second arches come
  together, the primitive ear is formed by day 50
  of gestation. The first 3 hillocks come from the
  first branchial arch and the second 3 from the
  second branchial arch.

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Branchial Apparatus Pyhologenetics Branchial
apparatus related to gill slits in fish.
Branchia (Greek) gills
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STRUCTURES DERIVED FROM BRANCHIAL ARCHES AND
POUCHES
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Types Fistula An abnormal passage extending
between mucosal surfaces. Sinus A blind
ending pit extending from an internal or external
surface. Cyst Persistant mucosal-lined,
fluid-filled cavity.
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1st Branchial cleft Unique

• 1st cleft is the only one that does not become
  obliterated completely by the eighth week of
  gestation
• It penetrates the underlying mesoderm toward the
  first pharyngeal pouch.
• The dorsal portion produces the external auditory
  meatus
• The middle portion forms the cavum conchae
• The ventral portion disappears.
• The membrane at the bottom of the cleft becomes
  the outer layer of the tympanic membrane.
• The ventral portion of the first pharyngeal pouch
  evolves to form the eustachian tube.
• The dorsal portion of both the first and the
  second pharyngeal pouches contributes to form a
  portion of the middle ear.

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1st Branchial Cleft Classification

• Arnot (1971)
• Type I any lesion in the parotid gland, lined by
  squamous epithelium, that presented in early
  adulthood. Theory these lesions were secondary
  to cell rests buried during obliteration of the
  cleft.
• Type II any lesion that developed during
  childhood in the anterior triangle of the neck,
  with a communicating tract to the external
  auditory canal. Theory These lesions resulted
  from incomplete obliteration of the cleft.
• Work (1972)
• Type I a duplication of the membranous external
  auditory canal. These cystic lesions are lined by
  squamous epithelium and end in a cul-de-sac at
  the bony plate at the level of the mesotympanum.
  Purely Ectodermal.
• Type II duplications of the membranous external
  auditory canal and pinna. These lesions contain
  skin and cartilage. Ectodermal and Mesodermal.
• Olsen (1980) Divided lesions into cysts,
  sinuses, and fistulas (surgical classification)
• Cyst no communication with the external ear
  canal or an external opening in the anterior
  triangle of the neck.
• Sinus a blindly ending space from an opening in
  the external ear canal.
• Fistula a patent ductlike structure with
  openings both in the external ear canal and in
  the anterior triangle of the neck.
• In practice, these classifications have not
  provided much clinical utility!

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Typical Depiction of the Work Classification.
Many have found this to be of limited utility
clinically, with up to 40 of lesions being
non-typable. Olsen's surgically oriented
classification seems to be the most useful scheme.
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A postauricular mass or abscess is seen in fewer
than 10 of patients.
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1st Branchial Cleft and CN7

• Facial nerve at risk !
• 1st branchial apparatus complete at 6 weeks,
  whereas facial nerve and muscles develop from
  weeks 6-8
• implies unpredicatble relationship of a 1st
  cyst/sinus to the facial nerve
• CN7 injury
• Injury most common in previously infected cysts.
• Temporary Injury
• nerve ID'ed vs. not-ID'ed 21 vs. 27
• Permanent Injury
• nerve ID'ed vs. not-ID'ed 1 vs. 12

Therefore, facial nerve monitoring and superfical
parotidectomy with CN7 identification is
advocated in all of these cases
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Membranous attachment (arrowheads) between the
floor of the external auditory canal and the
tympanic membrane. Left, Right ear. Right, Left
ear.
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First Arch Syndromes

• Malformations result from deficiencies in
  components of the first arch (primarly neural
  crest)
• Treacher-Collins Syndrome (mandibulofacial
  dyostosis)
• Abnormal external, middle and inner ear
• Malar and mandibular hypoplasia
• Lower eyelid defects
• Pierre Robin Syndrome
• Mandibular hypoplasia
• Cleft palate
• Eye and ear defects
• DiGeorge Syndrome
• Absence of the thymus
• Malformations of the mouth
• Nasal clefts
• Cardiac abnormalities

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Preauricular Pits/Cysts

• Can be associated with variety of syndromes
• Branchiootorenal syndrome (BOR) - Ear pits
• Beckwith-Wiedemann syndrome - Asymmetric earlobes
  with pits
• Mandibulofacial dysostosis (Treacher-Collins
  Syndrome) - Auricular pits/fistulas
• Oculoauriculovertebral dysplasia - Preauricular
  tags

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Preauricular Sinus

• Not the same as first branchial cleft cysts
• Inhereted in incomplete AD fashion
• 25-50 are bilateral
• Incidence in whites is 0.0-0.6, in African
  Americans and Asians is 1-10.
• Pathological event Failure of the 1st arch
  hillocks (of His) to fuse with the 2nd arch
  hillocks.

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Preauricular Sinus

• Histology
• consist of tubular structures of simple or
  arborized patterns
• tract may arborize and can be tortuous
• often full of keratin and are surrounded by dense
  connective tissue.
• duct of the sinus is lined with stratified
  squamous epithelium
• Duct usually connects to auricular perichondrium

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Fibrous walled cyst lined by ciliated,
respiratory-type epithelium.
Sinus tract through skeletal muscle.