Pinna

The gross and microscopic appearance is typical of keratoacanthoma: These are self-limited lesions that often regress on their own. Those that do not regress should be suspected of being squamous cell carcinomas. The typical squamous cell’ carcinoma does not regress. Basal cell carcinomas may also be raised lesions, but they also do not regress. A seborrheic keratosis tends to be a flatter (although raised), rough-surfaced, pigmented lesion that slowly enlarges over time. An actinic keratosis tends to be a flat, pigmented lesion that is tan to brown to red.

P. aeruginosa

Ear pain and drainage in an elderly diabetic patient must raise concern about malignant external otitis.  The swelling and inflammation of the external auditory meatus strongly suggest this diagnosis. This infection usually occurs in older diabetics and is almost always caused by P. aeruginosa.

(Braunwald, 15/e, p 190.) Ear pain and drainage in an elderly diabetic patient must raise concern about malignant external otitis. The swelling and inflammation of the external auditory meatus strongly suggest this diagnosis. This infection usually occurs in older diabetics and is almost always caused by P. aeruginosa. H. influenza and M. catarrhalis frequently cause otitis media, but not external otitis.

 Ans:A.)Ectoderm

• First branchial cleft is the precursor of external auditory canal.
• Around the sixth week of embryonic life, a series of six tubercles appear around the first branchial cleft

• Branchial clefts are ectodermal in origin.

Pinna is composed of a thin plate of yellow elastic cartilage, covered with integument

It is connected to the surrounding parts by ligaments and muscles; and to the commencement of the external acoustic meatus by fibrous tissue.

Thyroid cartilage is a type of hyaline cartilage. Hyaline cartilage is the most common type of cartilage, in adults this is replaced by bone by a process called enchondral ossification. In the articular surface of bone, costal cartilage, nose, larynx, trachea and bronchi hyaline cartilage persist throughout life and does not calcify.

Elastic cartilage: is highly flexible and is found in the external ear, walls of auditory tube, epiglottis and larynx.

Fibrocartilage is present in the intervertebral disc, pubis symphysis and certain joints.

Fibrocartilage is a white opaque structure due to dense collage fibres (type I and II).

When a fibrous tissue is subjected to pressure it is replaced by fibrocartilage.

It is seen in joints, symphysis, intervertebral discs, menisci and labra (shoulder joint and hip joint).

Pinna is a type of elastic cartilage. Elastic cartilages are seen at sites concerned with production or reception of sounds eg external acoustic meatus (lateral part), auditory tube and epiglottis.

A i.e. Eustachian tube opens at the level of inferior turbinate; B i.e. Pinna develops from the cleft of arch; C i.e. Growth of inner ear completed by 4^th month

Eustachian tube connects tympanic cavity with nasopharynx. It is about 36cm long in adults and runs downwards, forwards & medially at an angle of 45° with horizontal from bony tympanic end to slit like pharyngeal end. Tympanic end is in the anterior wall of middle ear, just above the level of floor. While nasopharyngeal end is situated in the lateral wall about 1 -1.25 cm behind the posterior end of inferiro turbinateQ

Auriculotemporal nerve, a branch of mandibular nerve (V₃)(2 supplies the external acoustic meatus, external surface of auricle above this, skin of temporal region and TM joint.

D i.e. Great auricular

A i.e. Vagus nerve; B i.e. Auriculotemporal nerve; C i.e. Great auricular nerve

A. i.e. Greater auricular nerve; B. i.e. Auriculotemporal nerve; C. i.e. Occipital nerve

Tympanic branch of glossopharyngeal (IX) nerve or Jacobson’s nerve supplies the medial (inner) surface of tympanic membrane. It does not supply pinnaQ.

Main nerves supplying the skin of auricle (pinna) are great auricular nerve (^c2, CP and auriculo temporal nerve (V3)(2 with a small contribution from lesser occipital nerve, (C2), auricular branch of vagus (X) nerve or Arnold’s nerve and facial nerve.

The great auricular supplies the whole of the cranial (medial /back) surface of auricle (C2, with a little overlap from the lesser occipital at the top) and the posterior part of lateral (front) surface (helix, anthelix, and lobule).

The auriculo temporal nerve (br. of CNV₃) supplies the upper part of lateral surface , skin of auricle anterior to external acoustic meatus, tragus, crus & adjacent part of helix and most of meatal skin.

Auricular branch of vagus (Arnold’s nerve) supplies skin on the concavity of concha & posterior part of eminentia , posterior wall & floor of meatus and adjoining tympanic membrane.

Ans. is ‘d’ i.e., Palm 

Skin over the pinna is closely adherent to the perichondrium on the lateral surface while it is loosely attached on the medial surface.

Ans. is ‘b’ i.e., Helix

• Darwin’s tubercle (or auricular tubercle) is a congenital earcondition which often presents as a thickening on the helix at the junction of the upper and middle thirds.
• The feature is present in approximately 10^.4% of the population.This acuminate nodule represents the point of the mammalian ear.

Ans. is ‘a’ i.e., Tragus and crux of helix

Incisura ternzinalis is the area between the tragus and crus of helix

Ans. is ‘a’ i.e., Hematoma ear

Hematoma of Auricle

• It is the collection of blood between the auricular cartilage and its perichondrium.
• It is often the result of blunt trauma seen in boxers, wrestlers and rugby players, so called Boxer’s ear.
• Extravasated blood may clot and then organize resulting in typical deformity of cauliflower ear.

The patient is presenting with features of postauricular subperiosteal abscess. Treatment for this is antibiotics along with drainage of abscess and cortical mastoidectomy.

This patient has developed this abscess as a complication of CSOM (History of chronic ear discharge) for which he requires meastoidectomy.