The pharyngoesophageal diverticulum in the lower part of the neck can be detected using neck ultrasonography. We present a case of pharyngoesophageal diverticulum mimicking a thyroid nodule, which was found incidentally by ultrasonography, and discuss its peculiar findings, which might be useful to diagnose pharyngoesophageal diverticulum and to prevent invasive procedures such as needle aspiration biopsy.
Aged ; Barium/diagnostic use ; Case Report ; Diagnosis, Differential ; Esophagus/radiography ; Human ; Male ; Thyroid Nodule/diagnosis/ultrasonography ; Zenker Diverticulum/diagnosis/*ultrasonography

Clinically evident metastases of carcinomas to the thyroid gland are rare, particularly from a colorectal primary tumor. We present a case of colonic adenocarcinoma metastatic to the thyroid gland with histopathologic and immunohistochemical findings. A 68-year-old woman with a history of Dukes' stage B colon carcinoma presented a mass in the thyroid gland. The tumor was confirmed to be metastatic adenocarcinoma from the colon. The immunohistochemical findings demonstrated positive staining for cytokeratin 20, low-molecular-weight cytokeratin, villin and carcinoembryonic antigen, but stains were negative for cytokeratin 7 and thyroglobulin.
Adenocarcinoma/secondary* ; Adenocarcinoma/radiography ; Aged ; Carcinoembryonic Antigen/analysis ; Carrier Proteins/analysis ; Case Report ; Colonic Neoplasms/pathology* ; Female ; Human ; Immunoenzyme Techniques ; Intermediate Filament Proteins/analysis ; Keratin/analysis ; Microfilament Proteins/analysis ; Thyroid Neoplasms/secondary* ; Thyroid Neoplasms/radiography ; Thyroid Nodule/radiography ; Thyroid Nodule/chemistry ; Tomography, X-Ray Computed ; Tumor Markers, Biological

Metastasis to the primary thyroid carcinoma is extremely rare. We report here a case of colonic adenocarcinoma metastasis to medullary thyroid carcinoma in a 53-yr old man with a history of colon cancer. He showed a nodular lesion, suggesting malignancy in the thyroid gland, in a follow-up examination after colon cancer surgery. Fine needle aspiration biopsy (FNAB) of the thyroid gland showed tumor cell clusters, which was suspected to be medullary thyroid carcinoma (MTC). The patient underwent a total thyroidectomy. Using several specific immunohistochemical stains, the patient was diagnosed with colonic adenocarcinoma metastasis to MTC. To the best of our knowledge, the present patient is the first case of colonic adenocarcinoma metastasizing to MTC. Although tumor-tumor metastasis to primary thyroid carcinoma is very rare, we still should consider metastasis to the thyroid gland, when a patient with a history of other malignancy presents with a new thyroid finding.
Adenocarcinoma/pathology/surgery ; Biopsy, Fine-Needle ; Carcinoma, Medullary/diagnosis/radiography/*secondary ; Colonic Neoplasms/*pathology/surgery ; Humans ; Male ; Middle Aged ; Neoplasms, Second Primary/*diagnosis ; Thyroid Gland/pathology ; Thyroid Neoplasms/diagnosis/radiography/*secondary ; Thyroid Nodule/diagnosis