1/3. Epithelial and mixed hepatoblastoma in the adult. Histological observations and general considerations.Two instances of hepatoblastoma in adults are reported, with one case representing a purely epithelial, the other a mixed epithelio-mesenchymal variant. The purely epithelial tumour, consisting entirely of so-called fetal elements, was present in the liver of a 35-year-old woman without any other hepatic changes, whereas the mixed tumour developed in the coarsely nodular liver of a 73-year-old man with a currently inactive cirrhosis. Besides the epithelial component, this case held predominantly indifferent spindle-shaped and histiocytic mesenchymal cells which frequently gave rise to osteoid and to bony trabeculae, and on occasion also to vascular structures, biliary ducts and even to groups of hepatocytes. The cytological and histological picture of both cases is comparable even in its details to that seen in the hepatoblastomas of early childhood. This concordance should be insisted upon as a diagnostic pre-condition if a mixed tumour in the adult, consisting of several components, is to be accepted as a hepatoblastoma. This similarity also enables us to recognize the purely epithelial variant of the hepatoblastoma in the older patient as belonging to this tumour category, and to separate it from other hepatic carcinomas. It is suggested that in these tumours the pluripotent cells, or the cells that have again become pluripotent, are derived from differentiated hepatocytes; no evidence in favour of the existence of a particular cellular subpopulation or of "stem cells" has been found.- - - - - - - - - - ranking = 1keywords = mixed tumour (Clic here for more details about this article) |
2/3. adenocarcinoma of the colon with choriocarcinoma in its metastases.A 49-year-old woman died from metastases from a colon carcinoma. This was predominantly an ordinary tubular adenocarcinoma but it included arease of much less differentiated appearance with giant cells, while the hepatic and pulmonary metastase were poorly differentiated and contained choriocarcinoma, as established by means of morphologic and immunocytochemical examination. The choriocarcinoma appeared to be due to metaplasia within the carcinomatous tissue. This and other similar cases of mixed tumours suggest that unexpected trophoblastic differentiation may result from aberrant differentiation of locally proliferating cells, rather than originating in ectopic germ cells or in foci of embryonic totipotent cells. Implications for possible origin and for classification of tumors are briefly discussed.- - - - - - - - - - ranking = 0.5keywords = mixed tumour (Clic here for more details about this article) |
3/3. neuroblastoma IV-S followed by extra-adrenal pheochromocytoma 15 years later.Common origin of sympathoblasts and pheochromoblasts from the neural crest cells is generally accepted. neuroblastoma and pheochromocytoma result from an abnormal proliferation of these committed cells. They are included in the group of neuroendocrine neoplasms, formerly named Apudomas. Previous reports of mixed tumours of neuroblastoma and pheochromocytoma, and ganglioneuroma and pheochromocytoma, support this hypothesis. A case of extra-adrenal pheochromocytoma in an adolescent who 15 years before was successfully treated for a stage IV-S neuroblastoma without evidence of primitive tumour is reported. Two hypothesis are formulated: (1) the second neoplasm may have arisen from the unlocated primitive tumour, probably silent evolution could be due to its maturation into ganglioneuroma-pheochromocytoma; (2) taken into account a common origin of both neoplasms, the patient may have a genetic predisposition to develop neuroendocrine tumours. Whatever the mechanism, second neoplasms, as the case reported, late relapses, and late toxic effects may justify long follow-up of neuroblastoma survivors.- - - - - - - - - - ranking = 0.5keywords = mixed tumour (Clic here for more details about this article) |