Occult Papillary Thyroid Carcinoma Initially Presenting as Cervical Cystic Lymph Node Metastasis: Report of Two Cases

Cervical cystic lymph node metastasis as the first and sole manifestation of occult papillary thyroid carcinoma (PTC) is uncommon, and can be mistaken for branchial cleft cyst. The present study reports two cases of PTC initially presenting as upper lateral neck cysts. Ultrasound examination confirmed the presence of occult papillary carcinoma with neck metastasis. The critical importance of ultrasound examination of the soft tissue of the neck for the identification of the clinical manifestations and the imaging features of occult PTC are discussed, with an emphasis on factors that may contribute to misdiagnosis.