IntroductionFollicular thyroid carcinoma (FTC) rarely metastasizes to regional lymph nodes, as they mainly metastasize through hematogenous route; in particular, a large FTC with only lateral lymph node metastasis and without distant metastasis has rarely been reported.Case reportWe present a 66-year-old male patient with a progressively growing thyroid for more than 20 years, causing tracheal compression and narrowing. Neck ultrasonography, computed tomography (CT), magnetic resonance (MR) imaging and positron emission tomography–computed tomography (PET/CT) were carried out to obtain images of the thyroid and surrounding tissues. Total thyroidectomy and cervical lateral and central lymph node dissection were undertaken, and histopathological, and immunohistochemical evaluations and molecular pathology confirmed the diagnosis of FTC with multiple cervical lymph node metastases.ConclusionWe have reported a rare case of large FTC with diffuse nodal involvement but no distant metastases. We present the thyroid ultrasound, neck CT, MR and whole body PET/CT.

IntroductionPapillary thyroid microcarcinoma (PTMC) that metastasizes to bone, especially metastasizes to contralateral humerus with so large mass, is rarely reported before.Case reportWe presented a 50-year-old female patient with a large painful mass in the right humerus for 5 years, presenting with swelling of the right shoulder with limited mobility. Positron emission tomography–computed tomography (PET/CT) showed a large mass in the right humerus, bilateral lung lesions, and enlarged lymph nodes in the right supraclavicular fossa. Right humerus lesion biopsy and immunohistochemical evaluations confirmed that the lesion originated from the thyroid tissue. Then, the thyroid ultrasonography showed a hypo-echoic solid nodule with an irregular taller-than-wide shape in the upper of left thyroid lobe and enlarged lymph nodes with the absence of fatty hilum in the contralateral right IV compartment. The total thyroidectomy and cervical lymph node dissection were undertaken; the histopathology confirmed the diagnosis of PTMC with contralateral cervical lymph node metastasis.ConclusionWe reported a case of PTMC with contralateral large humerus and cervical lymph node metastasis and demonstrated the PET/CT images of the metastatic large humerus and thyroid ultrasonographic appearances of the PTMC and enlarged cervical lymph node.