T-cell lymphoproliferative disorders are among the most challenging diagnoses in hematopathology.Unlike the more common B-cell disorders, in which clonality is often readily discernible by surface immunoglobulin light chain restriction, there is no specific immunophenotypic signature that is diagnostic of a clonal T-cell population. Immunophenotypic criteria that are helpful in the diagnosis of T-cell neoplasms include T-cell subset antigen restriction, anomalous T-cell subset antigen expression, deletion or diminution of one of the pan T-cell antigens, a precursor T-cell phenotype, and expression of additional markers (e.g., CD30, CD20, major myeloid antigens, and TCR␥␦). Analysis of the inherent forward and orthogonal light scatter properties of the cell can also provide important diagnostic clues. None of these features is 100% specific, however, for aberrant expression of pan-T antigens may be seen in viral infections, B-cell malignancies, or in reactive changes following administration of certain medications. An increased CD4:CD8 ratio is often observed in Hodgkin's lymphoma. Based on the analysis of 87 neoplastic and 80 control cases, we conclude that flow cytometric features that are most suspicious for malignancy include the loss or markedly dim expression of CD45; complete loss of one or more pan-T antigens; diminished expression of more than two pan-T antigens in conjunction with altered light scatter properties; and CD4/CD8 dual-positive or dual-negative expression (except thymic lesions). Cytometry (Clin. Cytometry) 50:177-190, 2002.

Metastasis of renal cell carcinoma to the head and neck, especially the larynx, is an extremely rare event. Most previously reported cases have involved a presenting laryngeal lesion that lead to the discovery of an underlying primary renal cell carcinoma. Even more unusual is the occurrence of an isolated laryngeal metastasis revealing itself years after nephrectomy, with an interim of undetected recurrence. We believe this case to be the first reported example of an isolated supraglottic laryngeal renal cell carcinoma metastasis occurring 7 years after radical nephrectomy. Local excision of such isolated lesions seems to offer a favorable prognosis.

Context.—As rejection in renal transplantation has become better controlled, gastrointestinal complications have become increasingly important. Ischemic colitis and colonic perforation are the most common of these lesions, contributing to morbidity and mortality in the early postoperative period. Objective.—We undertook this study to identify factors contributing to the risk of intestinal ischemia in patients undergoing renal transplantation and to define circumstances that may affect that risk. Methods.—We studied 356 patients undergoing renal transplantation during a 40-month period. We reviewed medical records, surgical pathology reports, autopsy reports, and pathology slides. Results.—Eleven (3.1%) of the patients developed ischemia of the small or large bowel or both within 20 days after transplantation, and 6 (54.5%) died as a result. Ten of these patients had received cadaveric kidneys and were older than 40 years. There was no sex predilection. The most common segment involved was the terminal ileum and ascending colon. We discuss possible reasons underlying these observations in this article. Conclusion.—The mechanism behind posttransplantation intestinal ischemia is multifactorial, but regardless of etiology, it is important to emphasize the risk of intestinal ischemia in patients who develop abdominal symptoms during the early posttransplantation period, particularly in patients older than 40 years who have received cadaveric kidneys.