Incidence of occult thyroid carcinoma metastases in lateral cervical cysts

To establish the incidence of thyroid carcinoma metastasis in adult patients presenting with apparently benign cervical cysts. The authors report their experience with four cases of papillary thyroid carcinoma who present with a lateral cervical cystic mass and no palpable disease in the thyroid gland. A retrospective review of patients undergoing surgery for solitary cervical cysts in our clinic from 1994 to 2002 was performed. Patients with a clinically obvious primary malignancy, age less than 16 years were excluded from the study. Thirty-seven patients were identified. A diagnosis of benign cervical cyst was shown by histological examination of the resected specimen in 32 patients (86.4%), with a mean age of 34 years (range, 16–59 years). A diagnosis of squamous cell carcinoma metastasis arising from an occult tonsillary primary was confirmed histologically in one patient (2.7%). Papillary thyroid carcinoma metastasis was confirmed by histological examination of the resected specimen in 4 patients (10.8 %), with a mean age of 29 years (range, 18–37 years). Diagnostic studies performed included ultrasound, computed tomography scan, fine-needle aspiration (FNA), and excisional biopsy. FNA was found to be helpful in only one of the 3 cases with papillary thyroid carcinoma metastasis. Final histopathological examination exhibited primary focus in the thyroid gland in all 4 patients, with a mean size of 0.5 cm (range, 0.3–0.8 cm). Our data indicate that nearly 1 out of every 10 lateral cervical cysts in young adult patients represents lymphatic metastases from occult thyroid carcinoma. An excisional biopsy for definitive diagnosis should be undertaken without prolonged delay, even if FNA does not reveal malignancy.