ANAPLASTIC CARCINOMA OF THE THYROID AT TH E NSTITUTO-NACIONAL-DE-LA-NUTRICION-SALVADOR-ZUBIRAN

Background. Anaplastic thyroid carcinoma (ATC) is a highly aggressive tumor with a median survival rate of 6 months. Aim. To analyze present ation, treatment, morphology, immunohistochemistry, and nuclear DNA an alysis of a cohort of patients with ATC. Patients and methods. Twelve patients with ATC (11 female) with a mean age of 65 years were seen at our hospital from 1970-1995. The data were obtained from the clinical records and the morphology, immunohistochemic studies and DNA pattern were performed in slides obtained from archival specimens. Results. P revious or coexisting thyroide disease was documented in 10 patients ( 9 multinodular goiters and one Grave's). The most frequent presentatio n was a rapidly growing tumor associated with dysphagia, cervical pain , hoarseness and dyspnea. A cold thyroid nodule was detected by thyroi d scan in 10 patients. The most frequent subtype was the spindle cell variety. Papillary thyroid carcinoma coexisted in eight cases, two of them corresponded to the tall cell variant. Reactivity for S-100 prote in and vimentin was studied in six patients: all were positive for S-1 00 protein and vimentin, 5/6 for epithelial membrane antigen, half for carcinoembriogenic antigen, 2/6 for thyroglobulin and calcitonin, and one for neuronal specific enolase. These six tumors showed a diploid DNA pattern. Tumor resection was achieved in 2/11 and none survived si x years after diagnosis. Conclusions. ATC is a highly aggressive tumor coexisting with thyroid pathologies. Spindle cell variant is the most frequent with positive reactivity for S-100 protein, vimentin and epi thelial membrane antigen. Most tumors have a diploid DNA content.