Cytological Diagnosis of an Uncommon High Grade Malignant Thyroid Tumour: A Case Report

Anaplastic Thyroid Carcinoma (ATC) is a relatively uncommon highly malignant tumour originating from the follicular cells of thyroid gland having poor prognosis. It accounts for 2% to 5% of all thyroid carcinomas and patients typically present with a rapidly growing anterior neck mass with aggressive symptoms. A 53-year-old male presented with diffuse neck swelling measuring 8x6 cm and right cervical lymph node measuring 2x2 cm since one month which was associated with dyspepsia and dyspnoea. Ultrasound and Contrast Enhanced Computed Tomography (CECT) neck revealed enlarged right lobe of thyroid and multiple enlarged cervical lymph nodes with soft tissue density nodules in bilateral lungs. Fine Needle Aspiration (FNA) from the swelling revealed giant cell, spindle cell and squamoid pattern. Focal areas showed follicular epithelial cells arranged in repeated microfollicular pattern suggesting an underlying follicular neoplasm. FNAC smears from the lymph node also revealed similar findings. Based on the cytomorphological and radiological findings, final diagnosis of ATC probably arising from underlying follicular carcinoma with cervical lymph node and lung metastasis was given. FNAC leads to prompt and definitive diagnosis, so that therapy can be initiated as soon as possible for better outcome. Multimodality therapy (surgery, external beam radiation, and chemotherapy) is the mainstay of treatment.