Volume 4, Issue 2 , Pages 80-83, March 2009
First branchial cleft cyst: A rare presentation with mesotympanic extension
Article Outline
Summary
A 2-year-old girl presented with a left middle ear cholesteatoma. A CT scan showed a mass in the left middle ear starting from the mesotympanum extending through a bony canal defect into the parapharyngeal space, deep to the facial nerve and ending in the submandibular region. The patient underwent surgical excision of the first branchial cleft cyst by superficial parotidectomy with facial nerve dissection and mastoidectomy with middle ear exploration. This case illustrates a rare presentation of a first branchial cleft cyst with histologic and anatomical features of both types of Work's classification of brachial cleft anomalies.
Keywords: First branchial cleft cyst, Cholesteatoma
1. Introduction
Anomalies of the first branchial cleft are relatively rare and often present with a variety of different signs and symptoms. Approximately 1–8% of all branchial anomalies are derived from the first branchial arch [1]. Other authors have found incidences of first branchial anomalies to be as high as 18–25% [2], [3].
First branchial anomalies may present as cysts or sinus tracts, all with an intimate relation to the external auditory canal and auricle [4]. However, the recognition and classification of these anomalies can be quite difficult and challenging. An unusual case of a 2-year-old female with a first branchial anomaly involving the mesotympanum and extending to the submandibular region is presented.
2. Case report
A 2-year-old girl presented with a left middle ear cholesteatoma. A CT scan showed a mass in the left middle ear starting just inferior to the incudostapedial joint and extending to hypotympanum with possible extension into the neck. A subsequent CT scan of the neck confirmed that the mass extended from the hypotympanum through a bony canal defect into the parapharyngeal space, deep to the facial nerve and ending in the submandibular region (see Fig. 1, Fig. 2).
Fig. 1.
Coronal CT showing cystic lesion in parapharyngeal space extending toward middle ear.
Fig. 2.
Coronal CT demonstrating branchial cleft cyst extending from parapharyngeal space toward submandibular region.
The patient underwent surgical excision of the first branchial cleft cyst with a superficial parotidectomy with facial nerve dissection and mastoidectomy with middle ear exploration. The cyst extended from the submandibular region anterior to the carotid sheath, and superiorly and deep to the parotid gland and facial nerve to enter the hypotympanum through a bony canal (which was lined by cartilage) ending in the mesotympanum (see Fig. 3, Fig. 4, Fig. 5). Histologic examination of the specimen demonstrated a cystic structure lined by squamous epithelium.
Fig. 3.
Intraoperative view of left middle ear: demonstrates cholesteatoma in mesotympanum.
Fig. 4.
Intraoperative view after superficial parotidectomy: demonstrates branchial cleft cyst extending from submandibular region, deep to facial nerve, and toward the hypotympanum.
Fig. 5.
Specimen.
At 5-month follow-up, the patient is doing well with no signs of recurrence and with normal facial nerve function and hearing.
3. Discussion
Arnot in 1971 proposed the first classification for first branchial cleft anomalies [5]. He designated as a Type 1 defect any cyst or sinus in the parotid gland that is lined by squamous epithelium and presents in early or middle adult life. Type II defects develop during childhood in the anterior triangle of the neck, with a communicating tract to the external auditory canal.
The more widely accepted classification of first branchial cleft anomalies was described in 1972 by Work and consists of Type I and Type II lesions [6], [7] (Fig. 6).
Fig. 6.
Adapted drawing of Work's classification of first brachial cleft cysts; Work WP. Newer concepts of first branchial cleft defects. Laryngoscope. September 1972;82(9):1581–1593.
A Type I lesion is of ectodermal origin, is free of cartilage, and is a duplication of the membranous external auditory canal. According to Work, in no cases of Type I lesions could cartilage be considered as a part of the duplicated external auditory canal. These lesions occur medial to the concha cartilage and extend to the post auricular crease. They pass superior to the facial nerve, parallel to the external auditory canal and end in a cul-de-sac on or near a bony plate at the level of the mesotympanum [6].
A Type II lesion contains both ectodermal and mesodermal components and is usually located as a sinus tract below the angle of the mandible. The tract will pass lateral, medial, or split the main trunk of the facial nerve. It may end inferior to the external auditory canal or end as a sinus tract at the bony cartilaginous junction. These lesions contain not only cartilage but skin as well. The middle ear is normal in these lesions.
Arohnson in 1976 reviewed Work's cases and concluded that the Type I anomalies were histologically epidermoid cysts and possess no cartilage or adnexal structure, and the Type II lesions contain skin, adnexal structures and cartilage [8].
However, as Finn noted, it may be difficult to correlate histological criteria of Work's Type I and Type II first branchial cleft anomalies in that skin, adnexae, and cartilage have been noted in anatomically type I malformations rather than ectodermal tissue alone [9]. Belenky and Medina also found that many cases of first branchial cleft anomalies do not fit neatly into these classifications [10]. Olsen et al. stated that classifications do not aid in the diagnosis or surgical management of such defects [11].
Our case illustrates all these points nicely. Our patient presented with a first branchial cleft anomaly that appears to have components of both Type I and II lesions. This lesion began as a keratin cyst in the mesotympanum, like a Type I anomaly; but it also extended through the parapharyngeal space and ended in the submandibular region. The lesion also had squamous epithelium and cartilaginous features, much like a Type II anomaly. The lesion required a combined approach for complete excision.
4. Conclusion
First branchial anomalies are uncommon and account for approximately 10% of all branchial defects. In our literature review, a first branchial cleft cyst presenting with extension into the mesotympanum is rare. Knowledge of this anatomical presentation, may help prevent incomplete treatment, decrease risk of recurrence, and should be considered in the differential for any middle ear mass with extension into the neck.
References
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PII: S1871-4048(08)00054-3
doi:10.1016/j.pedex.2008.08.001
© 2008 Elsevier Ireland Ltd. All rights reserved.
Volume 4, Issue 2 , Pages 80-83, March 2009
