Aggressive thyroid malignancy presenting with unusual site cutaneous metastasis

Abstract

Introduction: Anaplastic thyroid carcinoma (ATC) presenting with cutaneous metastasis is rare and only few cases have been reported so far. Commonly involved sites are the cervical region and the thorax. Anaplastic thyroid carcinoma has poor prognosis and no standard treatment has been documented however extensive surgery with curative treatment often with adjuvant radiation and chemotherapy are effective. Most common genetic mutation in ATC is P53 (20-83% cases), RAS mutation (up to 50%), BRAFV600E mutation (25%) p13KCA mutation (12-23%) and copy gain leading to Akt activation (38-61%). Case Presentation: In our study, we have reported a case of a 66 years old male patient who presented with thyroid, back and the ribs (right side) swelling with a radiological diagnosis of malignant thyroid lesion, FNAC was done from all of the above mentioned sites. FNAC smears from all sites showed pleomorphic atypical cells. A diagnosis suggestive of High Grade Epithelial Neoplastic lesion was given with a possibility of Anaplastic thyroid carcinoma with cutaneous metastasis. Conclusion: Anaplastic thyroid carcinomas (ATC) with cutaneous metastasis often present with solitary or multiple swellings as seen in many studies. Very few cases has been reported which has been diagnosed on FNAC. The case reported highlights multiple nodular swelling in neck, right side back and ribs. Cytomorphologically it was suggestive of anaplastic thyroid carcinoma with cutaneous metastasis, which is rare and only few cases documented. Keywords: Anaplastic Thyroid Carcinoma, Bethesda Thyroid cytopathology, Cutaneous metastasis, Squamoid differentiation, Thyroid Fine Needle Aspiration.