Occult papillary thyroid carcinoma presenting with cervical neck lymph node metastasis

Papillary thyroid cancer accounts for most cases of thyroid cancer. Although the prognosis is usually good, it often causes cervical neck lymph node metastasis. Cervical neck lymph node metastases have been reported even in the absence of a primary tumor in the thyroid glands, and these cases are referred to as occult thyroid cancer (OTC). The McGraw-Hill Concise Dictionary of Modern Medicine defines OTC as “unknown primary malignancy that is symptomless, which first manifests itself as metastases or secondary-paraneoplastic phenomena” [1]. Although the frequency of OTC has decreased owing to developments in cervical ultrasonography and improved accuracy of histological tests [2], rare cases are still reported. Due to the decreased frequency of OTC, a benign cervical neck lymph node mass is sometimes diagnosed, which can result in delays to more accurate diagnoses and appropriate treatment. Therefore, we report a case of OTC identified in a 74year-old male patient.