poorly differentiated thyroid carcinoma
Poorly differentiated (PD) thyroid carcinomas lie both morphologically and behaviorally between well-differentiated and undifferentiated (anaplastic) carcinomas.
A consensus meeting was held in Turin, Italy, where an agreement was reached concerning the diagnostic criteria for PD carcinoma. These include (1) presence of a solid/trabecular/insular pattern of growth, (2) absence of the conventional nuclear features of papillary carcinoma, and (3) presence of at least one of the following features: convoluted nuclei; mitotic activity >or=3 x 10 HPF; and tumor necrosis. (17667551)
References
Volante M, Collini P, Nikiforov YE, Sakamoto A, Kakudo K, Katoh R, Lloyd RV, LiVolsi VA, Papotti M, Sobrinho-Simoes M, Bussolati G, Rosai J. Poorly differentiated thyroid carcinoma: the Turin proposal for the use of uniform diagnostic criteria and an algorithmic diagnostic approach. Am J Surg Pathol. 2007 Aug;31(8):1256-64. PMID: 17667551