Intramitochondrial lamellar bodies in acute myeloblastic leukemia.

Intramitochondrial lamellar bodies were observed in three cases of acute myeloblastic leukemia. Two of the patients had M1 leukemia and the remaining patient M4 leukemia, by the FAB classification. In all three cases neoplastic cells contained dilated mitochondria that varied in size and shape and contained decreased numbers of cristae. Some mitochondria contained lamellar structures that resembled myelin figures and, occasionally, primary granules; these structures were more conspicuous in the central portion of the mitochondria. Regardless of the proliferating cell type (lymphoblasts, myeloblasts, or monoblasts), there are common ultrastructural changes that represent abnormal metabolic function, such as disorders of intramitochondrial protein synthesis. The exact meaning of these findings is not known; adequate interpretation will require further investigation of the biology of these neoplastic processes.

[Anatomopathologic and ultrastructural study of cardiac myxomas]. / Estudio anatomopatológico y ultraestructural de los mixomas cardíacos.

For clinicians, cardiac myxomas has been a diagnostic challenge. It may simulate a valvular disfunction. The present paper displays the morphologic aspects on 17 patients with the diagnosis of atrial myxoma. In 14 cases the tumor was located in the left atrium. In all the cases stellate shaped cells were seen within a myxoid matrix. The findings in this report support the idea that myxomas are tumors and not thrombi as it has been speculated in the literature. We also consider that the cell of origin of this neoplasm is a pluripotential cell which needs further studies.