ATYPICAL PRESENTATION OF THYROID MALIGNANCIES: A CASE SERIES

Abstract

Introduction: Differentiated thyroid cancer mainly metastasizes to regional lymph nodes and rarely to distant organs. Papillary thyroid carcinoma can metastasize via lymphatic pathway and follicular thyroid neoplasms through vascular channels. Here we present 3 cases with atypical presentations and synchronous/metachronous primary tumours (non-endocrine). Case Reports: Case 1: A 43-year-old female with no known comorbidities presented with right shoulder pain. X-ray showed a missing rib incidentally. A CT thorax suggested metastatic bony mass. PET CT for finding primary malignancy showed uptake in thyroid. Her TFT was normal. FNAC thyroid with bone biopsy confirmed follicular carcinoma thyroid with bone metastasis. Case 2: A 33-year-old male presented with hematuria was diagnosed to have renal cell carcinoma. He underwent right radical nephrectomy. A follow up PET CT as per protocol showed hypermetabolic hypodense nodule in the left lobe of thyroid gland. His TFT showed hypothyroidism, but patient had no related complains. Biopsy confirmed papillary thyroid carcinoma. Case 3: A 48-year-old female came with fever and cervical lymphadenopathy. USG neck showed TIRADS 4 lesion with retrosternal extension. FNAC taken from the lymph node showed chronic granulomatous lymphadenitis suggestive of TB with Mantoux test being positive. She was started on ATT but thyroid lesions still persisting with lymphadenopathy. She underwent total thyroidectomy and biopsy showed infiltrating neoplasm arranged in papillary pattern. Here, her TB was masquareding the thyroid malignancy. Conclusion: The clinical presentation of thyroid metastases to uncommon sites are difficult to diagnose. Thyroid malignancies presenting with atypical features are not uncommon, but at times diagnosis and timely management is difficult in such cases.