CLINICALLY UNDETECTABLE OCCULT THYROID PAPILLARY CARCINOMA PRESENTING WITH CERVICAL LYMPH NODE METASTASIS.

Background: Occult papillary thyroid carcinoma presented as isolated cervical lymphadenopathy without clinical and radiologic findings has been rarely reported.

Case Report: A 47 years old female patient admitted to otorhinolaryngology clinic with 4X3 cm sized cervical mass. Physical examination of the patient was noted as a nontender, firm, mobile lymph node at right lateral cervical region. There was no inflammatory or infection disease in the history of patients anamnesis and no abnormal value on laboratory tests. Ultrasound screening of the neck detected a lymph node with suspicious features for malignancy. Head and neck examination was normal and there is no evidence of a tumoral mass or nodule in the thyroid gland. Whole body scan of MRI showed no pathologic sign both in the neck and body. Excisional biopsy was performed and revealed a carcinoma with papillary morphology. Immunohistochemical staining features of the tumor confirmed a papillary carcinoma derived from the thyroid gland. Second look USG of the neck and thyroid was performed but it revealed no tumoral mass. The patient underwent total thyroidectomy with right functional and central lymph node dissection. Histological examination of the thyroid gland showed multicentric 2 mm sized, three foci of papillary carcinoma located in bilateral thyroid lobes and metastatic lymph nodes in the right side of the neck.

Conclusion: A metastatic cervical lymph node can be evidence of a clinically undetected occult papillary thyroid carcinoma. Specific immunohistochemistry staining of specimen may lead to appropriate surgery and progression of carcinoma may be hindered by application of additional RAI therapy.