HEREDITARY THYROGLOSSAL DUCT CYSTS

Objective: To examine the epidemiological and clinical characteristics of hereditary thyroglossal duct cysts (TGDCs). Data Sources: A comple te English-language literature review, assisted by MEDLINE and BIOSIS, of hereditary cases of TGDC was performed between 1975 and 1996. Thre e new cases from our institution were included in the study. Study Pop ulation: Patients with a diagnosis of hereditary TGDC. Data Extraction : All case reports were reviewed by multiple observers to confirm the diagnosis of hereditary TGDC. Data Synthesis: A review of the literatu re revealed that a hereditary pattern has been described in 18 patient s from 6 families; 11 of the 18 cases were reported in the United Stat es. We report 3 new cases of TGDC herein, bringing the total of US cas es to 14. In all 14 US cases, the patients were female, presented at a mean age of 6.1 years, and had a predominately autosomal dominant inh eritance pattern. These findings are in sharp contrast to those in int ernational cases (n=7), in which only 29% of the patients were female and the mean age at presentation was much older (16.2 years). An autos omal dominant pattern of inheritance was found in 2 of 3 foreign famil ies. Interestingly, the patients with an autosomal dominant pattern of inheritance were older than those with an autosomal recessive pattern (13.9 years vs 6.2 years, respectively). Conclusions: Cases of heredi tary TGDC are female predominant and usually have an autosomal dominan t pattern of inheritance. The sexual bias may be explained by genetic imprinting. Although no racial differences were noted in our study, di stinct variations in presentation based on nationality were present. T he recurrence rate after a Sistrunk procedure is similar to that in no nhereditary cases.