Tumour-induced osteomalacia: a rare cause of chronic pain and weakness.

Tumor-induced osteomalacia is a rare and often misdiagnosed condition that presents with progressively worsening unexplained chronic pain and proximal muscle weakness. The osteomalacia leads to multiple stress fractures which do not heal properly, leading to progressive disability. It is caused by chronic hypophosphatemia due to inappropriate urinary phosphate wasting. This is due to a typically benign mesenchymal tumor that over-secretes a phospaturic hormone. Neurologists need to appreciate the relevance of chronic hypophosphatemia in people with chronic unexplained pain, as timely diagnosis and treatment of tumour-induced osteomalacia can be curative.

Right pneumonectomy for resection of a posterior mediastinal follicular dendritic cell sarcoma arising from Castleman's disease.

Follicular dendritic cell sarcoma is a rare malignant neoplasm of immune accessory follicular dendritic cells and may be associated with Castleman's disease which is a known precursor to follicular dendritic cell sarcomas. We report a case of a follicular dendritic cell sarcoma arising in Castleman's disease in a 63-year-old man who presented with a large posterior mediastinal mass, which required a radical pneumonectomy for complete resection.

Peripheral blood smears of myelodysplasia patients: scanning electron microscope findings.

The utility of scanning electron microscopy in the evaluation of ordinary glass peripheral blood smears of patients with myelodysplasia and those uncertain for myelodysplasia is emphasized. Attention is directed to changes in segmented granulocytes. Comparison of ultrastructural findings in abnormal blood smears with control cases is made. Important findings include reduced cytoplasmic granule number, increased cell size, large cytoplasmic vacuoles, condensation of the peripheral cytoplasm, prominence of large cytoplasmic granules, irregular cytoplasmic perimeter, abnormal nuclear morphology, abnormal cell shape, and a necklace-like arrangement of cytoplasmic granules. Of these findings, reduced cytoplasmic granule number was the most specific finding, while condensation of peripheral cytoplasm was the most sensitive. Combination of these two morphologic findings may provide a strong predictor of myelodysplasia. The study included a limited test of unknown cases evaluated by one author, including two uncertain for myelodysplasia. Pitfalls in evaluating temporary pancytopenia not associated with myelodysplasia are noted.

Scanning electron microscopy of peripheral blood smears: comparison of normal blood with some common leukemias.

Peripheral blood smears prepared routinely from nonneoplastic and leukemia cases were studied using the scanning electron microscope (SEM). The peripheral blood glass slide is examined directly in the SEM following application of a thin carbon coat. The morphology of the nonneoplastic and neoplastic smears is described in detail utilizing the SEM secondary electron detector and backscattered electron detectors. Certain cell features are measured as well with the use of the measuring software resident in the SEM. The appearance of the SEM images of peripheral smear slides is compared to that of slides from fixed, processed, and sectioned bone marrow cases previously reported. The problem of cell constituent loss and overall shrinkage in the routinely processed and sectioned material is noted. The lack of these problems in the peripheral blood smear slides and their better appearance is emphasized. The resemblance of neoplastic cells to their normal counterparts is discussed. The monoblast resembles the normal monocyte but both cell size and nuclear size are greater; the moderately reticulated nuclear chromatin distinguishes the monoblast. Neoplastic lymphoid cells maintain the wispy extensions of the cytoplasm perimeter resembling microvilli and thereby differ from myeloid and monocytic cells. The neoplastic lymphoid cell shows coarse clumping of nuclear chromatin and in some instances coarse chromatin anastomoses to distinguish it from the normal lymphocyte. Lymphoid cells of acute lymphoblastic leukemia are 33% larger than those of chronic lymphocytic leukemia and normal lymphocytes. The neoplastic myeloblast has a finely granular nuclear chromatin, maintains a smooth cytoplasmic perimeter, and may show cytoplasmic reticulations. The myeloblast differs from the lymphoblast in that the former has a smooth cytoplasm perimeter. Further, myeloblasts show nuclear lobulations more frequently than lymphoblasts. Comparison of SEM findings with the three case studies by flow cytometry indicates satisfactory correlation. In case 15, flow cytometry indicated a monocyte subset positive for CD14 and CD64 among the neoplastic myeloid forms. A candidate for such a cell is recognized morphologically as well. The availability for SEM ultrastructural study of all the cells, both neoplastic and nonneoplastic, on a routine diagnostic smear slide is emphasized.

Diffuse alveolar hemorrhage after infliximab treatment of Crohn's disease.

Infliximab (Remicade), a chimeric monoclonal antibody to tumor necrosis factor-alpha (anti-TNF-alpha), is being used with increasing frequency in the treatment of Crohn's disease. Infliximab's safety profile to date has been good with reported adverse events being mild to moderate. We report a case of diffuse alveolar hemorrhage after the second infliximab infusion in a patient with Crohn's disease. The mechanism by which infliximab may have caused the observed pulmonary insult remains unknown. Physicians should be aware of the possible association between infliximab treatment and the development of alveolar hemorrhage. Future cases should be reported.

Bone marrow leukemias and lymphoproliferative disorders: scanning electron microscope diagnosis.

This work considers the primary diagnosis of bone marrow leukemias and lymphoproliferative disorders by using the scanning electron microscope (SEM). A total of 14 cases are studied, including 2 demonstrating bone marrow hyperplasia only. The utility of employing the ordinary pathology glass microslide with routine stain is emphasized, as well as certain capabilities of the SEM, including backscattered electron image, secondary electron image, and measurement program. Bone marrow hyperplasias, myeloid leukemias, and lymphoproliferative disorders are analyzed by comparing specific ultrastructural features, such as cell sizes, nuclear chromatin configuration and composition, nucleoli, nuclear contour, and cytoplasmic constituents, including granule population with sizes of such granules. These features set apart the common bone marrow neoplasms and can be a determinant in case diagnosis.