Endocrine Abstracts

Introduction: The cases of paragangliomas (PGLs) mimicking thyroid nodules were also reported in literature rarely. We will present a case of PGL (a carotid body tumor) that we initially evaluated as a thyroid nodule, and then diagnosed as a PGL.

Case report: A 74-year-old woman was admitted due to a mass in the right side of neck growing rapidly within the last 1 month. Physical examination revealed a hard and painless mass with smooth surface, extending from right thyroid lobe level to angulus mandibula. THS, free triiodothyronine, and free tetraiodothyronine were within normal ranges. Multinodular goitre was detected on ultrasound (US). US-guided fine-needle aspiration biopsy was performed in 3 nodules, and the nodules were reported to be benign. Core needle biopsy was performed for the nodules in right thyroid lobe due to suspected thyroid malignancy, and histopathological findings were found to be consistent with neuroendocrine tumor. Bilateral total thyroidectomy were performed, and during the surgery, a mass of 4×3 cm was seen in the right carotid artery bifurcation and excised. Microscopically, the tumor cells were arranged in well-defined nests (Zellballen) and encircled by a thin layer of S-100 protein and GFAP positive, and spindle-shaped sustentacular cells. Tumor cells vary in size and shape, and have a finely granular cytoplasm. The nuclei were round to oval with coarsely granular chromatin with a so-called salt- and-pepper appearance. In tumor cells, immunohistochemical CD56, synaptophisin, neuron specific enolase and chromogranin A were positive, but calcitonin, TTF-1 and Tg were negative. In light of these findings, the case was diagnosed with PGL, and the histopathologic findings of other thyroid nodules were consistent with colloidal nodules.

Conclusion: Cervical PGLs are uncommon tumors, so healthcare providers should take the likelihood of PGLs into account in the differential diagnosis of neck masses.