Anaplastic thyroid carcinoma:a clinicopathological study of 15 cases / 临床与实验病理学杂志

ABSTRACT

Purpose To investigate and summarize the clinicopathological features,immunophenotype,diagnosis and differential diagnosis of anaplastic thyroid carcinoma(ATC).Methods The clinicopathological features and follow-up data of 15 patients with ATC were reviewed and retrospectively ana-lyzed,and the histological features,immunophenotypic,and molecular features were observed.Results There were 8 males and 7 females with a mean age of 63.5 years.The largest tumor diameter was 45.9 mm(range,20-73 mm).Macroscopically,the tumors appeared nodular or lobulated,mostly firm to hard,with a cut surface of gray-white or gray-yellow in color,and were accompanied by hemorrhage,necrosis,and cystic changes.Mi-croscopically,the tumor exhibited diverse structures and cellular morphology mainly composed of epithelioid,spindle,multinu-cleated giant cells,rarely rhabdoid morphology(2 cases)and heterologous osteosarcomtoid differentiation(1 case).Two cases showed squamous cell carcinoma morphology as well.Among them,there were pure ATC in 11 cases while three cases had mixed papillary thyroid carcinoma components and one case had coexisting high-grade differentiated thyroid carcinoma compo-nent.Cervical lymph node metastasis was present in 6 cases.CK(AE1/AE3)expression was observed in 80%of the cases while PAX8 expression was seen in53.3%.Varying degrees of BRAF(VE1)expression were found in 42.9%whereas weak focal TTF-1 expression occurred only in two cases;and all cases did not express TG.Overall,genetic testing was performed in 8 cases(53.3%).The TP53 gene was the most frequently muta-ted gene(5/8,62.5%),followed by the RAS(3/8,37.5%)and BRAF(3/8,37.5%)genes,while the TERT combined with PIK3CA gene was mutated in only one case.Moreover,multiple gene mutations occurred simultaneously in five cases.Of the total fourteen patients who underwent follow-up,the mean and median survival times were 13.9 and 5.0 months,respec-tively.The disease-specific mortality rate reached 78.6%.Conclusion ATC is extremely rare,displaying unique histolog-ical characteristics,often accompanied by various gene muta-tions.It has a poor prognosis;therefore,establishing a defini-tive pathological diagnosis provides valuable evidence for predic-ting patient outcomes and guiding clinical management.