Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

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Case report
Table of Contents - Year : 2016 | Month : June | Volume : 10 | Issue : 6 | Page : PD10 - PD12

Diagnostic Dilemma in a Thyroid Incidentaloma: Second Primary versus Metastatic Nodule? PD10-PD12

Abid Ali Mirza, Esha Pai, Kodaganur Gopinath Srinivas, Shankarappa Amarendra, K.S Gopinath

Correspondence
Dr. Esha Pai,
802, Olive 1, Prestige St. Johns Woods, 80 St. Johns Cross Road, Koramangala, Bangalore -560029, India.
E-mail: dr.eshapai@gmail.com

With the increasing use of 18F-Fluro-Deoxyglucose (FDG) Positron Emission Tomography (PET) the number of thyroid incidentalomas is on the rise. Focal thyroid incidentalomas identified by FDG-PET have been reported to have a high incidence of malignancy. Neuroendocrine tumours of the thyroid are rare entities. The most common neuroendocrine tumour of the thyroid is medullary carcinoma. A thyroid nodule in a patient with a known neuroendocrine tumour must be differentiated from a primary medullary carcinoma which can present a diagnostic challenge to the clinician. A 65-year-old female patient was referred for thyroidectomy for a FNAC diagnosed follicular neoplasm of the left lobe of the thyroid, detected on FDG PET follow up. She was a known case of neuroendocrine tumour of the pancreas with no features suggestive of familial Multiple Endocrine Neoplasia (MEN) syndrome. The patient had undergone Whipple’s procedure elsewhere, 5 years back. Following total thyroidectomy, the final histopathology report was suggestive of a primary neuroendocrine tumour. We present this case to highlight the clinical dilemma in diagnosing a thyroid incidentaloma as a second primary neuroendocrine tumour versus a solitary metastatic nodule in the background of metastatic gastroentero pancreatic neuroendocrine tumour. Although clinically, a metastatic nodule should have been the obvious diagnosis, the histopathological and immunohistochemical features were in favour of a primary non-medullary Neuroendocrine Tumor (NET) of the thyroid.