Review of XXXX with focus on clinical and pathobiological aspects.

@entity1377 @entity548 @entity39 @entity5 @entity1358 @entity2008 @entity2909 @entity703
Recent studies have shown that @entity1358 ( @entity1358 ) is clinically and genotypically a distinct entity. @entity1377 account for about 10-15% of @entity703 . Macroscopically, the cut surface is yellow or brown in color and large @entity5 frequently show cystic change. @entity548 and @entity39 are common. Histologically, Delahunt and Eble have classified @entity1377 (small cells, single layer) and type 2 (large cells, pseudostratification) according to the cytoplasmic volume and thickness of the lining cells. In chromosomal analysis, gain of chromosomes 7 and 17, loss of Y chromosome and additional gains (chromosome 3q, 8p, 12q, 16q and 20q) are frequently found in type 1 @entity1377 , but the @entity2008 @entity1377 seems to be more heterogenous than that of type 1 @entity1377 . Mutations of MET proto-oncogenes in some cases of both hereditary and sporadic @entity1377 have recently been detected. Furthermore, all hereditary and sporadic @entity1377 with MET proto-oncogene show type 1 histological features. Type 1 @entity1377 generally seem to have a favorable prognosis, but type 2 @entity5 have a worse prognosis than do type 1 @entity5 . @entity1377 with @entity5 with predisposition to @entity2909 and @entity1377 , the histological features of which are basically different from those of usual @entity1377 , have also been recently reported. Since @entity1377 seem to constitute clinically, histologically, and even genetically more heterogenous groups than previously thought, further investigations are needed to characterize the subtype of papillary @entity1358 .
