A Clinicopathologic Series of 685 Thyroglossal Duct Remnant Cysts

Abstract

The clinical features of thyroglossal duct remnant cysts (TGDC) have been well described, however the histopathologic aspects of these lesions have not been addressed in a detailed manner. In particular, there has been no large community practice based series evaluating TGDC histologically compared with management outcomes. A retrospective review of all TGDC diagnosed between 2005 and 2015 was performed. Six hundred eighty-five patients were identified (344 males; 341 females). Age at presentation was bimodal (first and fifth decades) and ranged from 0.8 to 87 years (mean 31.3 years). Males predominate in children (150:111); females in adults (230:194). Patients presented most frequently with a mobile midline neck mass in an infrahyoid location. An associated skin fistula (n = 67) was twice as common in pediatric as adult patients. The average cyst size was 2.4 cm (range 0.4-9.9 cm) by imaging studies and 2.6 cm (range 0.2-8.5 cm) by pathologic examination; pediatric patients had smaller cysts (mean 2.1 cm) than adults (mean 2.8 cm). Histologically, 257 (38 %) TGDC were lined by respiratory epithelium alone, 68 (10 %) squamous epithelium alone, 347 (51 %) exhibited both respiratory and squamous epithelium, and 13 (1 %) had no identifiable epithelial lining. Four hundred eighty-four (71 %) TGDC had associated thyroid gland tissue present within the cyst wall (n = 282), skeletal muscle (n = 71), adipose tissue (n = 34), or a combination of these sites (n = 97). The hyoid bone was identified in 647 (grossly and/or histologically), and absent in 38. Surgical management consisted of Sistrunk procedure (n = 647), cystectomy (n = 31), or thyroidectomy/thyroid lobectomy (n = 7). Treatment related complications were observed in 6 patients, which included vocal cord damage, seroma, and hematoma. Recurrences developed in 20 (3 %) patients, 14 of whom were managed initially by cystectomy. Papillary thyroid carcinoma was identified in 22 (3.2 %) TGDC. In summary, TGDC show a bimodal peak in the 1st and 5th decades, commonly presenting as a midline cervical lesion below the hyoid bone, associated with a skin fistula in 10 %. Histologically TGDC are most commonly lined by a combination of respiratory and squamous epithelium. Thyroid gland tissue is identified in 71 % of cases (0.45 cm mean size), although not limited to the cyst wall, but present in the surrounding soft tissues. Rare TGDC may harbor malignancy (3.2 %). TGDC are most effectively managed by Sistrunk procedure rather than excision, which carries low rates of complications (1 %) and recurrence (3 %).

Thyroglossal Duct Cyst Carcinomas: A Clinicopathologic Series of 22 Cases with Staging Recommendations

“…Identification of ectopic thyroid gland tissue further confirms the diagnosis [4,9]. Some also recommend documentation of a normal thyroid gland that is free of malignancy prior to classifying a tumor unequivocally as a TGDC carcinoma [16,18,51].…”

“…Unlike nonneoplastic TGDCs, which show no gender predilection [2][3][4], TGDCCa affect women more frequently than men with a 3:1 female to male ratio observed in the present series, or 2.3:1 overall when including the literature ( Most patients present with a mobile midline neck mass, clinically indistinguishable from benign TGDC [2,13,17,[19][20][21]. The finding of a fixed mass has been emphasized as a possible indicator of malignancy [3,20,36], but was present in only 2 patients in this series.…”

“…In a minority of individuals, the thyroglossal duct does not undergo complete involution. Persistent remnants of the thyroglossal duct may manifest clinically as thyroglossal duct remnant cysts (TGDCs), characteristically presenting as a mobile midline anomaly in the anterior neck [1][2][3][4].…”

“…The reported incidence of carcinoma occurring in TGDCs ranges from \1 to 19.6 % [5][6][7][8][9][10][11][12][13][14][15][16], although probably more in the 2 % range when referral and academic bias are removed from consideration [4]. The vast majority of TGDC carcinomas (TGDCCa) are papillary thyroid carcinomas (PTCs), thought to originate from the ectopic thyroid gland tissue which is commonly (approximately 70 % of cases) found in association with TGDCs [2,4,7,9,[16][17][18][19][20][21][22]. The clinical presentation of TGDCCa do not differ significantly from that of nonneoplastic TGDC, although a fixed mass is worrisome, with most cases of malignancy diagnosed postoperatively following pathologic evaluation of the lesion [2,17,20,21].…”

Papillary carcinoma in thyroglossal duct cyst: Diagnosis by fine‐needle aspiration cytology and immunocytochemistry

“…Thyroglossal duct cysts (TDC) are among the most common cervical lesions encountered in infancy and childhood . Carcinoma associated with TDC is extremely rare, occurring in about 1% of cases .…”