Fine Needle Aspiration and Core Biopsy of Liver Mass as First Time Diagnosis of Sarcomatoid Anaplastic Thyroid Carcinoma, A Rare Malignancy Presenting at an Unexpected Body Site

Abstract

Abstract Introduction/Objective Anaplastic thyroid carcinoma (ATC) is a fatal malignancy. We report an unusual case of a patient with ATC whose chief complaint and clinical history were listed as “jaundice and liver mass” without mention of disease in the neck. Methods/Case Report A 66-year-old female presented to the emergency department with worsening “yellow-green skin discoloration” for a few weeks. She also reported worsening dyspnea and recent dysphagia with solid foods, fatigue, abdominal pain and recent hemoptysis. Physical examination revealed conjunctival icterus, jaundice, a tender neck mass, right upper chest wall tenderness and palpable lymphadenopathy in the lower neck. Assessment notes indicated inability to carry out self-care and being bedridden, even though she reported having been active, swimming and cycling, up to one month before her presentation. Computed tomography studies confirmed findings compatible with widespread malignancy with mass lesions in her liver, lungs, adrenals, kidneys, neck, pancreas, gallbladder, and brain. Mild anemia, hemoglobin 10.5g/dL, mild leukocytosis, leukocytes 17,000/mm3, were confirmed. Bilirubin was 15µmol/L, and hepatic enzymes were elevated. An ultrasound-guided liver biopsy was performed and evaluated for cytologic features, histologic features and pattern of immunoreactivity. The combined cytomorphologic and histologic features were those of a pleomorphic sarcomatoid high-grade malignancy with variably spindled to epithelioid morphology and associated necrosis. Immunohistochemical studies performed on sections from the accompanying core biopsy confirmed the malignant cells to be positive with CK-AE1/AE3, CK 7, TTF-1, GATA3, PAX8, SATB2, and BRAF V600E. The malignant cells were nonreactive with CK 20, thyroglobulin, calcitonin, napsin, CDX2, PCEA, and ER. The combined clinical setting, imaging findings, cytomorphology, histomorphology and ancillary testing results together allowed for a specific diagnosis of metastatic anaplastic thyroid carcinoma. The patient was referred for palliative care services and died within a few days of diagnosis. Results (if a Case Study enter NA) NA Conclusion Metastatic disease from a sarcomatoid ATC, as diagnosed in this case, is an important differential diagnosis to keep in mind when an elderly patient presents with multisite metastases from an undefined primary source. Clinical, radiological and laboratory correlations are of paramount importance in correlating with cytomorphology/histomorphology and in helping to determine the best panel of IHC studies to consider.