Clinical Geriatrics

An accumulation of fluid within a small chamber but with no epithelial or other membrane lining is called a pseudocyst. When this cyst-like structure develops within the cartilage of the auricle of the ear, also called the pinna, it is commonly referred to as an auricular pseudocyst, although it has also been referred to as cystic chondromalacia, intracartilaginous cyst, or endochondral pseudocyst in the medical literature.¹ Because auricular pseudocysts are benign and rare, they are easily overlooked or misdiagnosed by clinicians. When the condition is diagnosed correctly, medical or surgical interventions do not guarantee a successful outcome. We report a case of an auricular pseudocyst in an older man who we did not treat with medical or surgical intervention, but who was successfully monitored clinically. A literature review of the topic as well as typical therapeutic options and their usual outcomes are provided.

Case Report

During physical examination of a 74-year-old white man who was seen in our dermatology clinic for follow-up of bullous pemphigoid, we noted a noninflammatory fluctuant mass at the left superior antihelix that extended to the concha (Figure 1 [click thumbnail for larger view]). The mass was not tender, had no drainage, and was not associated with tinnitus. The patient stated he had no history of trauma, including chronic rubbing or scratching of the ear or sleeping on the left side. We determined that the mass was an auricular pseudocyst and elected not to treat, as the condition is not associated with disability, the treatments may cause discomfort, and there is a high incidence of recurrence following treatment. In addition, our patient was immunosuppressed secondary to his methotrexate and steroid use for bullous pemphigoid, so any interventional treatment at that time would have had an uncertain outcome.

The patient had two follow-up visits in our clinic within a 6-month time period for bullous

pemphigoid. We recorded that the auricular pseudocyst remained stable; it did not change in shape, there were no signs of inflammation, and no other symptoms had developed (Figure 2 [click thumbnail for larger view]). Based on these findings, we decided the best option would be continued clinical monitoring.

To our knowledge, this is the first reported case of a patient with an auricular pseudocyst being followed clinically with great success, without any medical or surgical intervention. Because of the immunosuppressed

state of our patient, any interventional procedure could result in significant complications. Physicians should be aware of the additional comorbidities of their patients, such as diabetes mellitus or immunosuppression from medications, when deciding whether to proceed with interventional therapy or to monitor the patient clinically.

 Discussion

Pseudocyst of the auricle is an uncommon benign condition that typically presents as a painless, fluctuant cystic mass commonly located at the triangular and scaphoid fossa of the ear.² The right ear is affected more frequently than the left, and only 13% of cases are bilateral.² Since auricular pseudocysts were first reported in the English literature by Engel³ in 1966 in a group of Chinese men,cases in white men,⁴ women, and other races have been reported, demonstrating no racial or gender predisposition to this clinical entity. The most common age of onset is the third decade of life, and it is uncommonly encountered in those younger than 20 years and in those older than 60 years.

Histologically, a pseudocyst of the auricle is characterized by an intracartilaginous cavity unlined by epithelium, hence the name pseudocyst. The most prominent histologic findings are intracartilaginous fibrosis and excessive granulation tissue along with a perivascular mononuclear infiltrate, which is lymphocyte predominant.^5,6 The lymphocytic infiltrate suggests an underlying inflammatory process in the pathogenesis of this condition. Aspiration of the lesion produces a viscous, sterile, straw-colored, albumin-rich fluid with an osmolarity and a glucose and protein concentration similar to that of plasma.⁷

Pathogenesis

The most prominent theory regarding the pathogenesis of an auricular pseudocyst is that of chronic minor trauma, which was first suggested by Engel,³ who thought the Chinese habit of sleeping on the right side against a hard pillow may have contributed to the occurrences he observed. Later evidence has shown that individuals who wear motorcycle helmets or frequently use stereo headphones are more prone to developing an auricular pseudocyst.⁸ Children with atopic dermatitis who constantly rub their ears have also been described as having this condition.⁹ It is possible that chronic trauma to the tissues from those activities can result in perichondral ischemia and cartilaginous degeneration, leading to the release of high amounts of hemosiderin and serum lactate dehydrogenase (LDH) into the cartilaginous fluid.^8,10 Two of the LDH isoenzymes—LDH-4 and LDH-5, in particular—have been reported to predominate in the cystic fluid, even when serum LDH levels have been normal.¹⁰

Congenital embryonic dysplasia of the auricular cartilage has been suggested to be the main predisposing factor in the formation of a pseudocyst. During the complex auricular developmental process, some residual tissue planes may be formed within the mesenchyme of the immature auricle, which may lead to the formation of an intracartilaginous pseudocyst upon reopening.⁷

High levels of interleukin-1 (IL-1) in the fluid have also been shown to play a significant role in the formation of an auricular pseudocyst in susceptible individuals.¹¹ IL-1 is well known for its central role in inflammation; it induces chemokine production to recruit leukocytes, activates endothelium to express adhesion molecules that are involved in cartilaginous inflammation, and triggers the synthesis of matrix metalloproteinases, leading to cartilage destruction.¹²