Branchial Arch Anomalies: Rates of Recurrence and Malignant Degeneration

BACKGROUND: Branchial cleft cysts represent one of the commonest neck masses in children and adolescents. Their etiology is controversial with some evidence suggesting lymphoid origin. Large case series are lacking with no studies addressing recurrence rates or risk of malignant degeneration.

METHODS: From 1/1/1976-7/29/2011, 422 subjects underwent excision of branchial cleft cysts at Mayo Clinic. Records were retrospectively reviewed. Features studied include age, gender, location, cyst type, symptoms, recurrence, extent of surgery, pathology as well as presence of tracts.  Associations with tracts, malignancy, and recurrence were evaluated using Wilcoxon rank sum, chi-square/Fisher exact tests and Cox proportional hazards regression models, respectively. 

RESULTS: Mean age was 26.2 years (range 0-87) with equal gender distribution. Frequencies of types 1, 2, 3 and 4 cysts were 19.4%, 75.6%, 4.3% and 0.7%, respectively. 39% of study participants had lesions associated with tracts. Mean age for the subjects with tracts was 15.7 years compared with 33.0 years for others (p<0.001).

Of the 416 subjects with available pathology, 76,8% had inflammatory changes  or cartilage with no identifiable epithelium. Various epithelial elements were identified in the remaining cohort. 2% had carcinoma or metaplasia. Mean age for the participants with carcinoma or metaplasia was 49.4 years compared with 25.9 years for others (p=0.002). Incidental discovery (p=0.002) and absence of tracts (p=0.013) were associated with carcinoma or metaplasia.

Among the 372 subjects with no previous surgery, 18 recurred at a mean of 38.7 months post-operatively. Among the 354 subjects who did not experience recurrence, mean follow-up was 94.9 months. Recurrence was more likely with bilateral cases (hazard ratio 5.11;p=0.030) and with drainage (hazard ratio 2.58;p=0.048). Other factors, including pre-operative imaging and extent of surgery, did not affect recurrence rates. While the presence of a tract was not associated with recurrence, subjects with tracts were more likely to have a history of previous excision (p<0.001) and more likely to be bilateral (p=0.007) and symptomatic (p<0.001).

CONCLUSION: Patients with bilateral cysts and those presenting with drainage should be followed more closely for recurrence the first 3 years post-operatively. Pre-operative work-up and extent of resection do not correlate with lower recurrence rates. Older patients presenting with incidental lesions should raise suspicion for malignancy.