RESUMO
The PAX8/PPARgamma (PPFP) fusion-oncogene is moderately specific for follicular thyroid carcinomas (FTC). It remains unknown whether this can be translated into improved diagnosis, classification, or outcome prediction. We studied a cohort of well-characterized follicular adenomas (FA), FTC, and Hurthle cell carcinomas (HCC) from patients with complete clinical follow-up, to determine whether PPARgamma immunohistochemistry (as a surrogate of PAX8/PPARgamma expression) helps to distinguish FA from FTC and to assess its diagnostic accuracy as an adjunct to frozen section. We also correlated PPARgamma staining with clinical outcomes to assess its role as a prognostic marker.PPARgamma staining was more common in FTC (31 of 54; 57%) than in HCC (one of 23; 4%) or FA (four of 31; 13%) (P < 0.000001). Adjunctive use of PPARgamma immunohistochemistry improved diagnostic sensitivity of intraoperative frozen section from 84% to 96% (P < 0.05) but reduced specificity from 100% to 90% (P < 0.05). PPARgamma staining was associated with favorable prognostic indicators (female gender, better tumor differentiation, and lesser risk of metastases).PPARgamma staining may be helpful in the differential diagnosis of FA, FTC, and HCC, particularly when diagnostic sensitivity of histomorphology is reduced (e.g. during intraoperative frozen section). PPARgamma staining also shows an association with favorable prognosis and may have a role in risk stratification.
Assuntos
Adenoma/química , Proteínas de Ligação a DNA/genética , Proteínas Nucleares/genética , Oncogenes , PPAR gama/análise , PPAR gama/genética , Proteínas Recombinantes de Fusão/genética , Neoplasias da Glândula Tireoide/química , Transativadores/genética , Adenoma/genética , Adenoma/patologia , Adulto , Idoso , Feminino , Secções Congeladas , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fator de Transcrição PAX8 , Fatores de Transcrição Box Pareados , Coloração e Rotulagem , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologiaRESUMO
Rosai-Dorfman disease (RDD), otherwise known as sinus histiocytosis with massive lymphadenopathy, is a rare histiocytic syndrome of unknown etiology, dominated by histiocytic and lymphocytic infiltration of enlarged lymph nodes. Thyroid involvement is rare and its impact unknown. We report a case of RDD involving the thyroid, initially diagnosed and managed as anaplastic carcinoma, and review the literature for previously reported cases of thyroid involvement. A 71-year-old woman sought further evaluation after treatment elsewhere for a 4-month history of a rapidly enlarging goiter causing local compression. Pathology was reported to show anaplastic thyroid carcinoma with prominent histiocytic infiltration. On review, we found characteristic features of RDD within the thyroid and cervical lymph nodes. The patient showed serologic evidence of autoimmune thyroid disease. Two years after thyroidectomy, there was no evidence of recurrent disease. We have identified only three previously reported cases of RDD involving the thyroid, all of them in women. In all cases, the patient has survived without evidence of disease progression, suggesting that thyroid involvement may not change the generally good prognosis of RDD. The description of autoimmune thyroid disease in our case and in two of the three previously reported cases, suggests a link with autoimmune thyroid disease.