TY - JOUR
T1 - Medullary thyroid cancer with undetectable serum calcitonin
AU - Brutsaert, Erika F.
AU - Gersten, Adam J.
AU - Tassler, Andrew B.
AU - Surks, Martin I.
N1 - Publisher Copyright:
Copyright © 2015 by the Endocrine Society.
PY - 2015/2/1
Y1 - 2015/2/1
N2 - Context: Calcitonin is a sensitive biomarker that is used for diagnosis and follow-up in medullary thyroid cancer (MTC). In patients with tumors > 1 cm, it is uncommon for preoperative serum calcitonin to be in the normal laboratory reference range in patients with MTC, and even more unusual for serum calcitonin to be undetectable. The Case: A 39-year-old woman was found to have a left thyroid nodule on magnetic resonance imaging done for neck pain. Ultrasound and fine-needle aspiration biopsy were performed, and cytopathology was positive for malignant cells. The cells also had features suggestive of a neuroendocrine tumor, and the specimen was immune-stained with calcitonin. There was positive immunoreactivity for calcitonin in isolated cells of the cytospin, highly favoring a diagnosis of MTC. Serum calcitonin was < 2 pg/mL (<6 pg/mL), and serum carcinoembryonic antigen was 3.1 ng/mL (<5.2 ng/mL). Given the low calcitonin levels, procalcitonin was also tested and was elevated at 0.21 ng/mL (< 0.1 ng/mL). The patient subsequently underwent a total thyroidectomy and central and ipsilateral lateral lymph node dissection. Histopathology confirmed a 2.6 × 2.0 × 1.2-cm MTC, with strong, diffuse immunostaining for calcitonin. Postoperatively, serum calcitonin has remained undetectable, carcinoembryonic antigen has remained within the reference range, and procalcitonin has become undetectable. Conclusions: We present a rare case of a patient with MTC with undetectable preoperative serum calcitonin, whose tumor demonstrated strong, diffuse immunohistochemical staining for calcitonin. We discuss the possible pathogenesis of calcitonin-negative MTC and the challenges in following patients with this condition.
AB - Context: Calcitonin is a sensitive biomarker that is used for diagnosis and follow-up in medullary thyroid cancer (MTC). In patients with tumors > 1 cm, it is uncommon for preoperative serum calcitonin to be in the normal laboratory reference range in patients with MTC, and even more unusual for serum calcitonin to be undetectable. The Case: A 39-year-old woman was found to have a left thyroid nodule on magnetic resonance imaging done for neck pain. Ultrasound and fine-needle aspiration biopsy were performed, and cytopathology was positive for malignant cells. The cells also had features suggestive of a neuroendocrine tumor, and the specimen was immune-stained with calcitonin. There was positive immunoreactivity for calcitonin in isolated cells of the cytospin, highly favoring a diagnosis of MTC. Serum calcitonin was < 2 pg/mL (<6 pg/mL), and serum carcinoembryonic antigen was 3.1 ng/mL (<5.2 ng/mL). Given the low calcitonin levels, procalcitonin was also tested and was elevated at 0.21 ng/mL (< 0.1 ng/mL). The patient subsequently underwent a total thyroidectomy and central and ipsilateral lateral lymph node dissection. Histopathology confirmed a 2.6 × 2.0 × 1.2-cm MTC, with strong, diffuse immunostaining for calcitonin. Postoperatively, serum calcitonin has remained undetectable, carcinoembryonic antigen has remained within the reference range, and procalcitonin has become undetectable. Conclusions: We present a rare case of a patient with MTC with undetectable preoperative serum calcitonin, whose tumor demonstrated strong, diffuse immunohistochemical staining for calcitonin. We discuss the possible pathogenesis of calcitonin-negative MTC and the challenges in following patients with this condition.
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U2 - 10.1210/jc.2014-3095
DO - 10.1210/jc.2014-3095
M3 - Article
C2 - 25490273
AN - SCOPUS:84922511533
SN - 0021-972X
VL - 100
SP - 337
EP - 341
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 2
ER -