Renal cell carcinoma with syncytial giant cell component.

We report a case of clear cell renal cell carcinoma in which a prominent multinucleated giant cell component was intermingled with clear, granular, and spindle cells. Histological, ultrastructural, cytometric, and cytogenetic features of giant cells were similar to those of mononucleated cells in the tumor, and therefore they were not from stromal or osteoclast derivation. These giant cells had homogeneous, finely granular, abundant cytoplasm, often with scalloped cell borders, and contained from 5 to more than 50 nuclei, all of them very similar in size and shape, with prominent central nucleoli.

Osteoblastic proliferation in bone biopsies from patients with end-stage chronic renal failure.

Osteoblasts have traditionally been considered to be terminally differentiated cells and therefore unable to divide. Data in recent years, however, indicate that cellular differentiation does not usually preclude preservation of proliferative ability and that most differentiated cells are able to divide under adequate stimuli. The aim of this study was to assess whether cubic osteoblasts undergo proliferation during the formation phase of the remodeling cycle under a stimulus that increased bone turnover.

DNA amplification in glial cells of progressive multifocal leukoencephalopathy: an image analysis study.

JC virus (JCV), the agent of progressive multifocal leukoencephalopathy (PML), has been shown by both immunohistochemistry and flow cytometry to be associated with p53 protein stabilization. Since stabilization/inactivation of p53 is associated with the development of genomic instability, abnormal cell DNA contents are to be expected in JCV-infected cells of PML. This work explores that possibility by image analysis evaluation of DNA content in PML-infected oligodendrocytes and bizarre astrocytes.