A Case of Type I and Type II First Branchial Cleft Sinus and Fistula

2016-07-30 20:13:24

Category: Pediatric radiology, Region: Head-Muscular system / Connective tissue / Skin, Plane: Coronal

The diagnosis of head and neck masses and fistulas can be challenging. Differential diagnoses include tumors, infections, or congenital lesions. Knowledge of embryology and anatomy of both common and rare anomalies, as well as indications for imaging, is required for timely diagnosis. We describe a branchial anomaly with atypical presentation as an uninfected “pit” in the earlobe that required multiple procedures to achieve complete resection. Reviewing the challenges experienced in the treatment of this case and the literature, we discuss the role of imaging in surgical planning to avoid incomplete resection, prevent recurrence, and minimize need for multiple procedures. CASE REPORT A healthy 3-year-old girl presented to the Otolaryngology clinic with history of rare moisture draining from a pit in her left earlobe. Though the pit was present since her birth, she passed her newborn hearing test. One prior infection of the earlobe was reported which responded to oral antibiotics. There was a second miniscule pale spot (no opening) under the mandible which has never drained. On physical examination, the left auricle and external auditory meatus were normal without evidence of duplication of the external auditory canal. On the anterior surface of the left earlobe was a 1-mm punctum with no obvious cyst or mass. Scant moisture was expressed when massaged. In the level II neck below the border of the mandible, a 2–3-mm flat, pale spot was noted. On palpation, the left parotid and face were normal without masses or facial nerve paresis. A clinical diagnosis of congenital left earlobe pit/fistula with left neck branchial remnant was made. Surgical excisions of both lesions were offered, and preoperative imaging was not ordered. When elliptical surgical excision for the neck spot was performed, no tract was identified deep to the skin. A separate elliptical incision was made around the ear lobe pit, and a lacrimal duct probe was used to identify potential fistula or tract. The probe only passed about 2 mm and did not lead to any tract, and the wound was closed primarily. The patient presented 3 weeks postoperative with a swollen and erythematous ear lobe with mucopurulent, sticky drainage (Figure 1). Cephalexin did not lead to improvement. The patient was taken to the operating room for incision and drainage of presumed localized wound abscess. Intraoperative exploration within the left earlobe soft tissue showed no identifiable tract or meatus. The wound was loosely closed to allow healing by secondary intention, and the patient was treated postoperatively with a course of antibiotics and topical 2% mupirocin ointment. Cultures for aerobic and anaerobic organisms were negative. The patient developed recurrent symptoms and another excision was performed with extension of dissection to the tragus. After removing all granulation, the surgeon identified a fistula completely lined by skin from the earlobe towards the auricle, appearing to end at the inferior aspect of the tragus. This tract was followed, and no cysts were identified. The tract was ligated and removed, and the wound was irrigated and closed. A histology report identified a fistula lined by stratified squamous keratinized epithelium and chronic inflammation. Once again, postoperative antibiotics and ointment were prescribed. Eighteen days later, the child had recurrent symptoms of erythema and drainage from the left earlobe. At this time, the surgeon recommended an MRI with contrast to identify the exact extent of the fistula. Given that general anesthesia was required for this study, the family declined the MRI, concerned their child had already undergone several anesthetics. Instead, they opted to proceed with another attempt at excision. The parents met with a second surgeon in the group, who ordered a repeat attempt at complete excision. The second surgeon excised all granulation tissue from the left ear lobule to the tragal cartilage again, as well as the cartilage of the anterior and inferior external auditory canal. After careful exploration, no further fistula was identifiable and the wound was closed primarily. The child did well for one month after the excision of the granulation tissue, but symptoms recurred. She was admitted for IV antibiotics and an MRI of the face/neck with contrast. Gadoterate meglumine (Dotarem; Guerbet, Bloomington, IN, USA) was given at the standard dose of 0.1mmol/kg. MRI revealed a large-caliber fistula starting from the left ear lobe, traversing medially through the parotid gland, deep and parallel to the facial nerve, then diving deep inferiorly, exiting through a pin point where the prior neck dimple was excised (Figures 2, 3). The fistula tract was anterior to the expected location of the facial nerve. Complete excision was performed the next day through a parotidectomy approach with facial nerve monitoring (Figure 4). The histopathological findings of the specimen showed a fistula tract lined by squamous keratinizing epithelium and adjacent parotid gland tissue (Figure 5).The skin and cartilaginous part of the inferior aspect of the external ear was also resected to ensure a complete excision of the fistula. The child recovered well without any complications and was asymptomatic at the 12-month follow-up. Figure 1: Gross specimen showing left earlobe abscess with erythema, edema, and purulent drainage. Figure 2: Coronal T2 weighted fat saturated image through the mid parotid gland. Dark arrow shows the double dark lines representing the walls of the fistula (tubular structure) starting from the lower ear lobe extending medially in a horizontal fashion, diving down dividing the parotid gland (white arrows) into a medial and lateral part. Figure 3: Sagittal T2 weighted fat saturated image showing similar finding in a different plane. Black arrow shows the double black tube (fistula) dives anteriorly and inferiorly from the horizontal component of the fistula after making almost a 90-degree angle. The distal end of the fistula ends at the pit of the left mandibular angle. The fistula divides the parotid gland into an anterior and posterior part on this plane. Figure 4: Intraoperative gross specimen: Parotidectomy approach with facial nerve dissected and identified. The entire tubular fistula is found to be deep to the facial nerve. A lacrimal duct probe has been inserted though the fistula (dark arrow) proximally with an Ellis clamp. The fistula ends distally near the mandible. Figure 5: Image with H&E staining at 12.5x magnification. Fistula tract lined by stratified squamous keratinizing epithelium (single-headed arrow) and adjacent parotid gland tissue (double-headed arrow).