Typical and atypical chronic lymphocytic leukemia differ clinically and immunophenotypically.

We compared the features of 17 cases of atypical chronic lymphocytic leukemia (aCLL) with those of a clinical control group of 24 cases of CLL. Quantitative flow cytometric data, available for 12 cases, were compared with an immunophenotypic control group of 58 cases using a relative fluorescence indexfor CD5, CD23, CD79b, and surface immunoglobulin light chain (sIg). Compared with the clinical control group, patients with aCLL had a higher mean WBC count and a lower platelet count. Patients with aCLL had a significantly higher probability of disease progression. Compared with an immunophenotypic control group of 58 CLL cases, 12 cases of aCLL demonstrated significantly higher expression of CD23. There was no significant difference in expression of sIg, CD79b, or CD5 between the groups. CD38 expression was noted in only 1 (9%) of 11 tested cases; 2 (18%) of 11 cases had trisomy 12. aCLL can be distinguished from typical CLL morphologically, clinically, and immunophenotypically. Atypical morphologic features in CLL seem to be a marker of aggressive clinical behavior.

Usefulness of CD79b expression in the diagnosis of B-cell chronic lymphoproliferative disorders.

We evaluated anti-CD79b for its usefulness in the diagnosis of B-cell chronic lymphoproliferative disorders (BCLPDs), particularly chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). We analyzed 100 BCLPDs for CD5, CD19, CD20, CD23, CD79b, and surface immunoglobulin light chain (sIg) expression by 4-color flow cytometry. CD20, CD79b, and sIg expression were quantified. Correlational analysis and univariable and multivariable logistic regression models were used to determine the best combination of antigens for the immunophenotypic classification of CLL vs other BCLPDs. Positive and statistically significant Spearman pairwise correlations between CD20, CD79b, and sIg fluorescence intensity were demonstrated. In the simplest models in which a single variable was considered, cutoff points were chosen that gave misclassification rates for CLL of 16% for CD79b, 19% for sIg, and 18% for CD20. Low-intensity CD79b, CD20, and sIg are associated highly with CLL. A panel containing CD5, CD19, CD23, and sIg allowed correct classification of most cases. Addition of CD20 or CD79b improved diagnostic accuracy; CD79b was slightly better than CD20. CD79b seems to be a useful addition to a standard flow cytometry panel for the evaluation of BCLPDs.

The neuropathology of orthotopic liver transplantation: an autopsy series of 16 patients.

OBJECTIVE: To examine the neuropathologic findings seen in the setting of orthotopic liver transplantation (OLT) and to asses the role, if any, that the neuropathology had in the patient's death. DESIGN: Retrospective autopsy series of 16 patients. SETTING: Tertiary referral center with a high volume of liver transplantation. PATIENTS: Sixteen OLT patients who died and in whom a complete autopsy, including examination of the brain and spinal cord, was performed. RESULTS: Sixteen patients, including 13 women and 3 men, comprised the study group. Patients ranged in age from 25 to 64 years (mean 44.8 years). Postoperative OLT survival ranged from 1 to 1962 days (mean 236 days). Reasons for the initial OLT included hepatitis (n = 6), fulminant hepatic failure (n = 4), cryptogenic cirrhosis (n = 2), methotrexate toxicity (n = 1), postoperative complication (n = 1), primary biliary cirrhosis (n = 1), and hepatocellular carcinoma (n = 1). Autopsies in 13 (81%) patients showed neuropathology; in only 2 patients, however, was the primary cause of death attributable to these findings. The most common neuropathology was related to anoxia or infarction, specifically, ischemia or focal neuronal necrosis (n = 9), infarction (n = 4), and diffuse anoxic encephalopathy (n = 3). Other central nervous system findings included infection with Aspergillus, Candida, and Toxoplasma (n = 3). The most common cause of death was infection-related in 8 patients. One patient died of pulmonary hypertension, 1 of acute rejection, and 1 of possible hyperacute rejection. Two patients died directly as a consequence of neuropathology findings; one had massive central edema with herniation, and the other had a large intracerebral hemorrhage with herniation. The exact cause of death was unclear in 3 patients. CONCLUSIONS: The most common neuropathology findings in this series were related to ischemia and infarction. Neuropathology findings are a significant cause of morbidity, but were only rarely the main cause of death (n = 2) in the OLT patients in this study.

Plexiform neurofibroma with and without associated malignant peripheral nerve sheath tumor: a clinicopathologic and immunohistochemical analysis of 54 cases.

Plexiform neurofibroma (PNF) is an important part of the diagnostic criteria for neurofibromatosis type 1 (NF1) and is a known precursor lesion of malignant peripheral nerve sheath tumor (MPNST). We studied the clinicopathologic features of 54 cases of PNF for which the hematoxylin- and eosin-stained slides and paraffin blocks were available and adequate clinical follow-up could be obtained. In addition, in all cases, a representative section of the PNF and, when present, MPNST, was evaluated immunohistochemically with an antibody for p53 (DO7). The cohort included 28 male patients and 26 female patients, with an age range from 4 to 79 years (mean, 27 yr). Of these 54 patients, 46 (85%) met the strict diagnostic criteria for NF1. Thirty-nine patients had PNF alone; 15 patients had an MPNST arising from the PNF (PNF/MPNST). Those patients with PNF/MPNST tended to be older (38 yr vs. 22 yr) and to have larger tumors (10.5 cm mean vs. 7.4 cm mean) than those with PNF alone. In 9 patients (23%) of 39 with PNF alone, local recurrence developed, whereas in 7 patients (47%) of 15 with PNF/MPNST, recurrent MPNST developed, and metastases developed in 3 (20%) of the 15. Immunohistochemically, only 1 case (2.5%) of 39 cases of PNF alone stained for p53. On the other hand, 12 (80%) of 15 cases of PNF/MPNST showed p53 immunoreactivity in the MPNST component, 2 of which also showed staining in the PNF areas. In conclusion, we found that the vast majority of patients with PNF met the strict diagnostic criteria for NF1. The immunohistochemical detection of intranuclear p53 protein is common in the malignant areas of PNF/MPNST but is rare in the PNF regions. The rarity of p53 staining in the PNF regions precludes its use in predicting those tumors that are likely to progress to MPNST.