Thymic carcinomas are rare tumors thought to derive from thymic epithelium. Because of the complex embryological origin of the thymus, whose development includes contributions from the third and, to a lesser extent, the fourth pharyngeal pouches, thymic carcinomas are endowed with great morphologic heterogeneity. A large number of histologic types have been described that resemble tumors arisin...

In this pa~r the morphologic characteristics of renal adenoma are studied in 4 groups of kidneys from 500 unselected autopsies performed for legal reasons, 5.000 autopsies from the files ofa general hospital, 16 kidneys with adenom3 and without carcinoma, and 200 kidneys with carcinoma. All the tUlnors were classified by pattern. cytology and sclerosis of lhe renal nontl.lmoral stroma The relat...