Unusual presentation of a first Branchial cleft cyst associated with an abnormal bony canal -a case report

Abstract

Background: First branchial cleft anomalies are rare, accounting for only 10% of all branchial cleft anomalies. We report an even more rare and unique case of a branchial cleft cyst with features of both first and second arch derivatives.

Case presentation: A 6-year-old boy presented to us with a left conductive hearing loss associated with pre-tympanic keratin debris and an ipsilateral painful cervical mass. He had a past medical history of left ear surgery for presumed cholesteatoma 2 years prior and left neck abscess drainage 6 months prior. CT and MRI revealed a lesion originating in the external auditory canal and extending cervically through a bony canal located medial to the facial nerve and terminating as a parapharyngeal cyst. The complete removal was accomplished in one surgical stage consisting of three distinct steps: robotic assisted transoral resection of the pharyngeal cyst, an endaural approach and a parotidectomy approach.

Conclusion: We believe that our detailed description of this rare first branchial cleft cyst with pharyngeal extension, possibly a hybrid case between a first and second branchial cyst, can serve as a valuable tool to Otolaryngologists - Head and Neck Surgeons who come across a similar unusual presentations.

Keywords: Cholesteatoma; Cyst; First branchial; Parapharyngeal; Robotic.

Fig. 1

Imaging. a. Coronal CT scan and b. Coronal T2 weighted MRI key images demonstrating the bony canal lying medial to the facial nerve and a voluminous pharyngeal cyst

Fig. 2

Intra-operative photographs. a. Robotic-assisted photograph of the pharyngeal cyst excision. b. Microscope image of the bony fistulous tract. The facial nerve and the external auditory canal (EAC) are labeled

Fig. 3

Histopathological analysis. a. High power H&E slide of the pharyngeal cyst revealing squamous epithelium, intraluminal keratin debris and the absence of pilosebaceous units, respiratory epithelium or associated lymphoid tissue. b. Low power H&E slide of the external auditory canal lesion revealing keratinized squamous epithelium with abundant intraluminal keratin debris