Sonography of the Ear Pinna - SKIN ULTRASOUND PINNA article.pdf · Sonography of the Ear Pinna Ximena Wortsman, MD, Gregor B. E. Jemec, MD, DMSc Objective. This study was undertaken

Sonography of the Ear Pinna

Ximena Wortsman, MD, Gregor B. E. Jemec, MD, DMSc

Objective. This study was undertaken to assess the scope of sonography for the diagnosis of diseasesof the external ear. Methods. We developed a description of the sonographic anatomy of the normalear pinna, including the thickness of the normal cartilage and lobule, through systematic scanning ofthe external ears of 11 healthy volunteers (2 male and 9 female), and reviewed clinical cases withpathologic entities. Results. Reproducible and recognizable images were collected from normal as wellas pathologic cases of the external ear. Images are presented for reference. Conclusions. Sonographypermits good visualization of the internal structure, including the cartilage, and it is possible to usesonography as a method of study to differentiate between inflammation, vascular lesions, and tumors.Key words: ear sonography; external ear imaging; pinna sonography; skin sonography; vasculartumor sonography.

Received November 1, 2007, from the Departmentof Radiology, Clinica Servet and Clinica Hospital delProfesor, Santiago, Chile (X.W.); and Department ofDermatology, Roskilde Hospital, University ofCopenhagen, Copenhagen, Denmark (G.B.E.J.).Revision requested November 21, 2007. Revisedmanuscript accepted for publication December 20,2007.

Address correspondence to Ximena Wortsman,MD, Department of Radiology, Clinica Servet,Almirante Pastene 150, Providencia, Santiago, Chile.

E-mail: [email protected]

he ear pinna is a highly specialized structure thatserves to collect sound and conduct it to the mid-dle ear. In broader terms, it is also a prominentaspect of the head and may be the seat of a num-

ber of diseases. Because the pinna is attached to the sideof the head in a relatively visible position, it can be trau-matized and exposed to sun damage easily. Althoughthere is much medical information about complicationsassociated with ear disorders and complications of hear-ing and the internal ear, there is not much written aboutcomplications of the outer ear, known as the pinna andauricle. The diagnosis of ear pinna diseases is done main-ly through clinical examination and biopsy, and, to ourknowledge, the possible benefit to physicians andpatients of supplementary noninvasive real-time imag-ing techniques has not been evaluated. Before a moreformal evaluation of such efforts, however, the scope ofnoninvasive sonographic imaging should be described.

With the appearance of high-frequency probes andhigh-resolution sonography machines, it is possible tovisualize layers of the skin,1 and this technology maytherefore aid in assessing the characteristics of thepinna’s internal structure, which is composed mainly ofskin layers and cartilage. To our knowledge, the normalsonographic structure of the ear pinna has not previous-ly been described.

© 2008 by the American Institute of Ultrasound in Medicine • J Ultrasound Med 2008; 27:761–770 • 0278-4297/08/$3.50

T

Image Presentation

27.5.jum.online.qxp:Layout 1 4/16/08 9:38 AM Page 761

Sonographic Technique

To establish the normal sonographic anatomy ofthe ear pinna, we studied the external ears of 11healthy volunteers (2 male and 9 female). Theirmean age ± SD was 35.3 ± 7 years (range, 24–46years). The pathologic images included in thisarticle were acquired from 16 patients (11 maleand 5 female) studied at the Department ofRadiology in one of the hospitals. The mean ageof the patients was 27.8 ± 25.9 (range, 1month–80 years). All of the patients or one ofthe parents in the case of the children signedtheir informed consent before the inclusion inthe study. Ethics Committee approval wasobtained for this study.

The sonography equipment used was an HDI5000 system (Philips Medical Systems, Bothell,WA) with compact linear array 15-7 MHz andlinear array 12-5 MHz transducers. Extendedfield-of-view software was used to acquireimages of the whole pinna length when needed.A copious amount of gel was used in patients toallow optimal visualization of the pinna. Nostandoff pad was necessary.

A piece of cotton inside the external meatuswas used during the examinations to prevententrance of the gel, and the patient was laiddown and rolled over to the opposite side of thelesion in the decubitus lateralis position, leav-ing the lesion side closer to the operator.

Children younger than 4 years with a suspi-cion of vascular tumors required sedation withchloral hydrate (50 mg/kg), administered orallyapproximately 30 minutes before the examina-tion, to prevent artifacts during flow detectionby color Doppler spectral curve analysis.

Transverse, longitudinal, and extended field-of-view images were obtained. Color Dopplerimaging and spectral curve analysis were usedto describe the vascularity of the auricularlesions.

Measurements in the healthy volunteers weretaken to establish the thickness of the cartilagein millimeters at the middle third of the antihelixin the transverse axis (Figure 1), and measure-ments of the lobule in millimeters were alsotaken from the anterior aspect of the epidermisto the posterior aspect of the epidermal layer inthe transverse axis.

Normal Sonographic Anatomy

On sonograms, it is possible to distinguish 2 dif-ferent zones of the ear pinna: an upper regionand a lower region. The anatomic difference ismainly the presence or absence of cartilageinside the layers. The upper region correspondsto the higher two thirds of the ear pinna and con-sists of 3 layers: anterior and posterior, eachdepicted as echoic thin skin layers, and a middlelayer containing cartilage, which is representedas a completely hypoechoic regular thin bandthat follows the different concavities and convex-ities of the ear pinna (Figures 2 and 3).

The cartilage is thick at the antihelix border ofthe auricula. The mean thickness in the normalcartilage at the antihelix border (middle third inthe transverse axis) of the 11 healthy individualswas 0.8 ± 0.1 mm (range, 0.7–0.9 mm).

The lower region is depicted by the ear lobule,which is a 1-layer structure and consists of onlyskin because of the absence of cartilage in thisarea. Sonographically, it is possible to recognizethe echoic epidermal and dermal layers as well asthe hypoechoic fatty tissue of the subcutaneous

762 J Ultrasound Med 2008; 27:761–770


Figure 1. Normal surface anatomy of the pinna.


component, comparable with the normal sono-graphic anatomy of skin elsewhere on the body(Figure 4). The mean thickness of the lobule inthe healthy individuals was 6.9 ± 1 mm (range,5.9–8.1 mm).

The blood supply could be traced to branchesof the external carotid artery.

Sonography of Pathologic Entities in theEar Pinna

The pinna has many features that render it partic-ularly amenable to evaluation with sonography.Its inherent superficial location, concavities, andskin-cartilage compound structure make it diffi-cult to study with other ionizing radiation imagingmodalities such as radiography and computedtomography. The multiplanar and real-timecapabilities of sonography without the necessityof using intravenous contrast agents can play anadvantage over magnetic resonance imaging.

Diseases that affect the ear pinna include acomplex range of entities that can be classified ascongenital malformations, inflammatory dis-eases, benign tumors, and malignant tumors.

Congenital MalformationsCongenital malformations of the pinna are relat-ed to developmental defects of the first and sec-ond branchial arches and the branchial groove,which joins the first pharyngeal pouch to formthe external ear canal.

Defective closure of the first branchial cleft orfailure of fusion of the primitive ear hillocks mayresult in formation of a small pit, sinus, or fistulain front of the pinna. These deformities can varyfrom a small dimple (preauricular pit) to a largersinus (preauricular sinus). Preauricular pits areshallow invaginations in the skin of the facelocated just in front of the anterior border of theanterior crus of the helix. A foul-smelling cheesydischarge of desquamated keratin debris can beencountered. A preauricular sinus is deeper thanthe pit and is lined with stratified squamous ker-atinizing epithelium. Preauricular pits andsinuses can become infected, and if they do, theinfection frequently recurs. If the opening of apreauricular sinus is occluded, the sinus will be

J Ultrasound Med 2008; 27:761–770 763

Wortsman and Jemec

Figure 2. Transverse image of the pinna showing a hypoechoicband of cartilage (C).

Figure 4. Transverse image showing the skin layers at the lobesegment of the pinna. Note that there is absence of cartilage inthe middle zone.

Figure 3. Longitudinal image at the upper two thirds of thepinna showing the different skin and cartilage layers.


converted into a cyst, which slowly becomesenlarged. With sonography, it is possible to followthe tracts to deeper planes and to establish thereal extension in the thickness of these lesions,even before any clinical inflammation is noticed.Inflamed preauricular sinuses can involve thecartilage and also can lead to inflammation ofdeeper structures in the vicinity such as theparotid gland (Figures 5 and 6).

Inflammatory DiseasesSeveral inflammatory disorders may appear onthe external ear. Some are identical to skin dis-eases seen elsewhere on sun-exposed skin, where-as others are unique to the ear.2 The causes ofinflammation can be mainly divided into trau-matic, infectious, autoimmune, and allergic types.

Acute or chronic friction that irritates the peri-chondrium of the auricular cartilage can inducea subperichondrial serous or serosanguineouseffusion. Blunt trauma encountered in boxing,rugby, football, and other physical activities inwhich the skin of the pinna is exposed to twistingor shearing forces can produce hematomas.Fluid collections are easy to identify with sonog-raphy as in any other segments of the humanbody. They are depicted as anechoic areas, andsonographically guided puncture or drainage ofthese collections is also possible.

Chondritis or PerichondritisAcute perichondritis of the auricle is a bacterialinfection of the perichondrium and underlyingcartilage. This type of acute bacterial infection is

potentially serious because if untreated, theunderlying auricular cartilage will becomeinfected and ultimately necrotic with the col-lapse of the pinna. Gram-negative bacteria, espe-cially Pseudomona aeruginosa and Proteus, arethe usual causative organisms. In the presence ofinflammation, the cartilage increases in thick-ness and echogenicity. At advanced states ofinflammation, the cartilage can appear beaded(Figures 7 and 8).

Sonographically, it is possible to detect thepresence of dissecting fluid collections of the car-tilage because these may divide the normallyuniform 1-layer hypoechoic cartilage into a 2-layer structure (Figures 9 and 10).

Depending on the density of the material, col-lections can be anechoic or echoic. During an

764 J Ultrasound Med 2008; 27:761–770


Figure 5. Ear pit–appearing lesion located at the anterosuperi-or aspect of the pinna in an 18-year-old female patient.

Figure 7. Prominent external auricular border (helix, arrow) in a20-year-old male patient.

Figure 6. Transverse image showing the real extension of thetract (between arrows) that corresponds to a deep ear sinusinvolving the cartilage (C).


examination, it is important to study the dynam-ic properties of any collection by compressing itwith the probe to confirm that it contains freefluid without inner septa. Drainage or punctureof these collections under sonographic guidanceis also possible if needed for diagnosis or therapy.

Postpiercing or Earring InflammationBecause of the wide use of earrings and piercingin different parts of the body, it is not uncom-mon to see complications from the use of theseitems. As shown in a study by Fisher et al,3 carti-

lage piercing may produce serious conse-quences because of the high risk of infections.Pseudomona aeruginosa is commonly involved,and ear piercing in the upper two thirds of theauricle is inherently more risky than piercinglocated at the lobe because of the possibility ofcartilage damage.4

The tract of the earring or piercing is detectableon sonography as a hypoechoic area that followsthe axis of installation (Figures 11 and 12). Ifthere is inflammation at the ear pinna, both thedermal layer and the cartilage increase in thick-ness and echogenicity.

J Ultrasound Med 2008; 27:761–770 765

Wortsman and Jemec

Figure 9. Chronic enlargement and suppuration of the pinna ina 59-year-old male patient.

Figure 11. Focal lump (arrow) in a 15-year-old female patientwith history of a piercing installed and subsequently removed atthe helix of the left pinna.

Figure 8. Transverse image from the patient in Figure 7 show-ing that the cartilage is increased in thickness and echogenicity.The cartilage has a beaded shape (between arrows), which iscompatible with chronic perichondritis.

Figure 10. Transverse image of the patient in Figure 9 showing adissecting fluid collection of the cartilage, not suspected by clinicalobservation (between arrows), that produces a double hypoechoiccartilage band. The high viscosity and debris present in the fluidproduce an appearance that is more echoic than usual. Also notethe increase in thickness and echogenicity, secondary to the edemaat the skin layers, compared with the normal pinna echo structure.


If there is any doubt about the presence ofinflammation, it is necessary to make a right-to-left side comparison at the pinna. A colorDoppler scan will show an increase in the vascu-larity of the affected area.

TumorsThe most frequently encountered tumors andtumorlike lesions of the ear pinna that can becharacterized on sonography are epidermalcysts, vascular tumors, cartilage tumors, and skintumors.

Epidermal CystsEpidermal cysts are slow-growing round, firmintradermal cysts that arise most commonlyfrom the infundibula of hair follicles. They are theresult of proliferation of epidermal cells within acircumscribed space of the dermis and subcuta-neous tissue. The most common sites fordevelopment of epidermal cysts are along thepostauricular sulcus and the medial aspect of thelobule at its junction with the face. They containcheesy debris composed of keratin. If an epider-mal cyst becomes infected, the lining of the cystmay rupture, and the keratin squames within thecyst can spill out into the surrounding soft tissue.An acute foreign body granulomatous reactioncan develop in response to the keratin squamesthat infiltrate the tissue surrounding an infectedepidermal cyst.

Sonography shows a hypoechoic round or ovalstructure that produces acoustic posteriorenhancement. The presence of cheesy densematerial inside the cyst can produce a misdiag-nosis of a solid mass by inexperienced operator,but the presence of acoustic posterior enhance-ment and the possibility of compression in thisthick fluid-filled cystic structure can help avoidthis pitfall. At later stages of inflammation, theshape of the cyst becomes irregular because ofrupture of the cyst and spillage of keratin into thesurrounding tissue.

Color Doppler imaging can show a scant pres-ence of vascularity in noninflamed cysts, butwith progression of inflammation, the vasculari-ty is increased in the periphery of the lesion(Figure 13).

Vascular TumorsHemangiomas and vascular malformations canbe present in the ear pinna. The external ear is thesecond most common site for extracranial arteri-ovenous malformations in the head and neck.5

The sonographic characteristics are not differentfrom those seen in vascular tumors in other partsof the body. Hemangiomas are benign tumorsconsisting of numerous vessels that frequentlyresolve spontaneously during the first decade oflife. It is important to differentiate hemangiomasfrom vascular malformations because the latterdo not resolve spontaneously. Also, it is impor-tant to know the depth of the involvement of thepinna and adjacent structures, which can com-plicate regression and lead to potential aestheticconsequences in a child.

Color Doppler sonography shows highly vascu-lar components that include arterial and venousflow between solid hypoechoic areas. It is also pos-sible to detect involvement of cartilage and sur-rounding structures such as the parotid gland andesternocleidomastoid muscle (Figures 14 and 15).

Vascular malformations are errors in the mor-phogenesis of the vessels. They can be dividedinto arterial, venous, capillary, lymphatic, ormixed types according to the nature of the ves-sels involved. They persist without changethroughout life. Sonographically, they appear asnumerous tortuous and serpiginous vessels fre-quently without solid hypoechoic areas in themiddle. On color Doppler sonography with spec-

766 J Ultrasound Med 2008; 27:761–770


Figure 12. Transverse image from the patient in Figure 11showing a hypoechoic tract (between arrows) suggestinginflammation left by the auricular piercing that crossed the car-tilage (C). This is associated with a hypoechoic dermal and sub-cutaneous area also caused by inflammation, which producedthe clinical lump on the pinna (dot).


tral curve analysis, the type of flow, mean thick-ness, and velocity of the vascular componentscan be detected (Figures 16–18). This fact could

be important in terms of planning or deciding ona cosmetic or surgical procedure; for example,arterial vascular malformations containing high-velocity vessels are not good candidates for laserprocedures, as are capillary flow malformations.

Lymphatic malformations appear as cystic orcomplex multiseptated masses without anydetectable flow. It is important to observe whetherthere is a feeding vessel susceptible to emboliza-tion in cases of arterial or venous malformationsand to determine the whole extension of thelesion, including any possible cartilage or adja-cent structure involvement, for which otherimaging modalities such as magnetic resonanceimaging and angiography can be required.

Cartilage TumorsChondromas are tumors derived from the carti-lage matrix. Extraosseous presentations of chon-dromas are uncommon compared with osseouspresentations. They may appear bilaterally onthe ears.6 On sonography, they appear as nodularsolid hypoechoic enlargements of the cartilage(Figures 19 and 20).

Malignant Skin TumorsSkin cancers such as basocellular and squamouscarcinomas are more frequent in persons whohave had long exposure to sunlight. The objectiveof sonography in these cases is to determine theamount of involvement of the pinna layers andadjacent structures and not to perform a histolog-ic diagnosis of the neoplastic lesion. Malignant

J Ultrasound Med 2008; 27:761–770 767

Wortsman and Jemec

Figure 14. Vascular lesion in the pinna and adjacent tissues in a1-month-old female patient.

Figure 13. A, Palpable lump at the lobule (arrows) in a 20-year-old male patient. B, Transverse image from the same patientshowing a round cystic lesion with some echoic debris inside(between calipers and arrow) at the lobular segment of thepinna. C, Transverse color Doppler image from the same patientshowing an increase in the presence of vascularity surroundingthe cystic lesion (arrows)

A

B

C


768 J Ultrasound Med 2008; 27:761–770


lesions generally appear as hypoechoic andheterogeneous areas with irregular borders.Sometimes ulcerations at the epidermal layer arerecognizable. The vascularity is increased insideand in the periphery of the tumor, mainly in thesubtumoral zone. Invasive growth of a tumor canbe detected and measured, which can help inplanning surgery or further deep imaging studies(Figures 21–23).

Discussion

Until now, the ear pinna has only been studied byclinical observation, occasionally supplementedwith biopsies. Imaging has rarely been done orneeded. Using an additional imaging modality,however, may have several advantages: it mayprovide structural information noninvasively, without the need for an intravenous contrast

agent; it may provide data for posterior longitu-dinal studies of biological processes; and it mayprovide new data because the images are gener-ated by principles that are different from those ofvisible light (eyesight of a clinician) and histolog-ic biopsy.

Sonography permits imaging of the knownstructures of the ear pinna and provides real-time helpful information about commonabnormalities. The appearance of sonographi-cally visible cartilage may be useful for develop-ment of therapeutic procedures. Similarly,quantification of structural components in vivonot only allows better preoperative planning butalso may be of diagnostic help.

Figure 15. Transverse gray scale (A) and color Doppler (B)images of a lesion showing a heterogeneous mass (betweenarrows) containing high vascularity (between arrows), compati-ble with a hemangioma.

A

B

Figure 16. Erythematous lesion on the helix of the pinna(arrows) in a 9-year-old female patient.

Figure 17. Transverse color Doppler image from the patient inFigure 16 showing a highly vascular arterial lesion with tortuousvessels, compatible with an arterial vascular malformation. Thereis no evidence of a solid tumor.


Current state-of-the-art technology makes itpossible to establish differential diagnosesbetween lesions and to characterize them bydiameter, thickness, whether they are solid orcystic in nature, and the amount and type of vas-cularity and to provide reliable presurgical infor-mation. The development of sonography as astandalone technology for diagnosis of skin andcartilage lesions is currently under study, but thetechnology already provides a guide for achiev-

ing better precision in procedures such as punc-tures, drainages, and biopsies.

Previously, simpler 20-MHz sonographicdevices have been used to evaluate the thicknessand state of the cartilage in reconstructed ears.7

Additional information about diseases, however,may also be obtained with more modern sonog-raphy machines. Some skin diseases have anestablished sonographic profile, as shown in pre-vious studies in dermatology,8 whereas, to ourknowledge, other entities, such as chondritis andpiercing complications, have not been describedpreviously. It may be speculated that early recog-nition of a condition such as chondritis wouldallow for more precise interventions and fewercomplications, although this obviously requiresspecific prospective investigations.

J Ultrasound Med 2008; 27:761–770 769

Wortsman and Jemec

Figure 18. Color Doppler spectral curve analysis from thepatient in Figures 16 and 17 showing arterial flow with a highpeak systolic velocity, which can be as high as the peak systolicvelocity normally seen in the external carotid artery.

Figure 20. Transverse image from the patient in Figure 19showing a solid nodule (between calipers) following the axis ofthe cartilage, which was confirmed as a chondroma of thepinna.

Figure 19. Protuberant nonpainful palpable lesion on the helixof the pinna (arrow) in a 26-year-old male patient.

Figure 21. Squamous carcinoma at the posterior aspect of thepinna in 79-year-old male patient.


It is suggested that sonography, as a widelyavailable imaging technology, can provide clini-cally relevant information for studying the earpinna. The composite images obtained providereal-time information about tissue characteris-tics, which otherwise would either remain hid-den or require biopsies.

References

1. Wortsman XC, Holm EA, Wulf HC, Jemec GB. Real-timespatial compound ultrasound imaging of skin. Skin ResTechnol 2004; 10:23–31.

2. Wortsman X, Jemec GB. High-resolution ultrasound appli-cations in dermatology [in Spanish]. Rev Chilena Dermatol2006; 22:37–45.

3. Fisher CG, Kacica MA, Bennett NM. Risk factors for carti-lage infections of the ear. Am J Prev Med 2005; 29:204–209.

4. Keene WE, Markum AC, Samadpour M. Outbreak ofPseudomonas aeruginosa infections caused by commercialpiercing of upper ear cartilage. JAMA 2004; 291:981–985.

5. Wu JK, Bisdorff A, Gelbert F, Enjolras O, Burrows PE,Mulliken JB. Auricular arteriovenous malformation: evalua-tion, management, and outcome, Plast Reconstr Surg2005; 115:985–995.

6. Quercetani R, Galli R, Pimpinelli N, Reali UM. Bilateral chon-droma of the auricle. J Dermatol Surg Oncol 1988; 14:436–438.

7. Danter J, Siegert R, Weerda H. Ultrasound measurement ofskin and cartilage thickness in healthy and reconstructedears with a 20-MHz ultrasound device [in German].Laryngorhinootologie. 1996; 75:91–94.

8. Wortsman X, Holm EA, Jemec GB. Ultrasound imaging ofthe subcutaneous tissue and adjacent structures. In: SerupJ, Jemec GB, Grove G (eds). Handbook of NoninvasiveMethods and the Skin. 2nd ed. Boca Raton, FL: CRC Press;2006:515–531.

770 J Ultrasound Med 2008; 27:761–770


Figure 22. Transverse image from the patient in Figure 21showing a hypoechoic solid lesion in the dermal and subcuta-neous tissue at the posterior aspect of the pinna with an ulcer-ation at the center, which is close but does not involve the car-tilage layer (C).

Figure 23. Transverse color Doppler image from the patient inFigures 21 and 22 showing high vascularity inside the lesion,which after surgery was histologically confirmed as a squamouscarcinoma.


Sonography of the Ear Pinna - SKIN ULTRASOUND PINNA article.pdf · Sonography of the Ear Pinna Ximena Wortsman, MD, Gregor B. E. Jemec, MD, DMSc Objective. This study was undertaken

Documents