Pseudocyst of the Auricle

Updated: Nov 02, 2016
  • Author: William P Baugh, MD; Chief Editor: Dirk M Elston, MD  more...
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Overview

Background

Pseudocyst of the auricle was first reported by Hartmann in 1846 and first described in the English literature in 1966 by Engel. [1] Historically, pseudocyst of the auricle has been addressed by many terms, including endochondral pseudocyst, intracartilaginous cyst, cystic chondromalacia, and benign idiopathic cystic chondromalacia. Because the condition is uncommon, it may be misdiagnosed or underreported by clinicians. Pseudocyst of the auricle is characterized as a benign, noninflammatory swelling to the ear, located on either the front or side surface. [2]

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Pathophysiology

The etiology of pseudocyst of the auricle is unknown, but several pathogenic mechanisms have been proposed.

Originally, Engel postulated that lysosomal enzymes might be released from chondrocytes and cause damage to the auricular cartilage. However, analysis of pseudocyst contents revealed a fluid rich in albumin and acid proteoglycans, with a rich cytokine milieu but lacking in lysosomal enzymes.

Analysis of the cytokine profile of the fluid indicates markedly elevated levels of interleukin (IL)–6, which is believed to stimulate chondrocyte proliferation. IL-1, an important mediator of inflammation and cartilage destruction, induces IL-6. IL-1 also stimulates chondrocytes to synthesize proteases and prostaglandin E2 while inhibiting the formation of extracellular matrix components.

Others have suggested that a defect in auricular embryogenesis contributes to pseudocyst formation. This defect causes the formation of residual tissue planes within the auricular cartilage. When subjected to repeated minor trauma or mechanical stress, these tissue planes may reopen, forming a pseudocyst.

Pseudocysts usually present spontaneously or following repeated minor trauma. [2] The observation that an auricular pseudocyst often results after repeated minor trauma, such as rubbing, minor sport injuries, ear pulling, sleeping on hard pillows, or wearing a motorcycle helmet or earphones, has led to the suggestion that these minor traumas may be the mechanism. In support of this traumatic etiology, elevated serum lactic dehydrogenase (LDH) values have been reported within the pseudocyst fluid. [3, 4] Two of the elevated isoenzymes, LDH-4 and LDH-5, are proposed as major components of human auricular cartilage. These enzymes may be released from auricular cartilage degenerated from repeated minor trauma.

One article reports that pseudocysts can be regarded as simply a variation of othematoma or otoseroma. [5]

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Epidemiology

Frequency

Tan and Hsu reported the epidemiological features, clinicopathologic characteristics, and success of surgical treatment in 40 patients of different Asian groups presenting with pseudocyst of the auricle. [6] Results showed a Chinese predominance (90%), followed by Malays (5%), and Eurasians (5%). All except one patient had unilateral presentations. Most (55%) presented within 2 weeks of auricular swelling. Few (10%) had a history of trauma.

Race

Most reports of pseudocyst of the auricle have involved Chinese or white patients; however, persons of all racial groups have been affected.

Sex

Males show a higher prevalence of pseudocyst of the auricle than females. [7]

Age

Most pseudocysts of the auricle are unilateral and occur in men aged 30-40 years, but lesions are documented in patients ranging in age from 15-85 years of both sexes.

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Prognosis

Without treatment of pseudocyst of the auricle, permanent deformity of the auricle may occur.

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Patient Education

Patients with pseudocyst of the auricle should be informed that even with optimal therapy, recurrence is common. Avoidance of triggers or exacerbating factors should be encouraged.

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