Net Inflow: An Important Target on the Path to Aquifer Sustainability.

Aquifers supporting irrigated agriculture are a resource of global importance. Many of these systems, however, are experiencing significant pumping-induced stress that threatens their continued viability as a water source for irrigation. Reductions in pumping are often the only option to extend the lifespans of these aquifers and the agricultural production they support. The impact of reductions depends on a quantity known as "net inflow" or "capture." We use data from a network of wells in the western Kansas portions of the High Plains aquifer in the central United States to demonstrate the importance of net inflow, how it can be estimated in the field, how it might vary in response to pumping reductions, and why use of "net inflow" may be preferred over "capture" in certain contexts. Net inflow has remained approximately constant over much of western Kansas for at least the last 15 to 25 years, thereby allowing it to serve as a target for sustainability efforts. The percent pumping reduction required to reach net inflow (i.e., stabilize water levels for the near term [years to a few decades]) can vary greatly over this region, which has important implications for groundwater management. However, the reduction does appear practically achievable (less than 30%) in many areas. The field-determined net inflow can play an important role in calibration of regional groundwater models; failure to reproduce its magnitude and temporal variations should prompt further calibration. Although net inflow is a universally applicable concept, the reliability of field estimates is greatest in seasonally pumped aquifers.

Best Practice Guidelines for Pre-Launch Characterization and Calibration of Instruments for Passive Optical Remote Sensing.

The pre-launch characterization and calibration of remote sensing instruments should be planned and carried out in conjunction with their design and development to meet the mission requirements. The onboard calibrators such as blackbodies and the sensors such as spectral radiometers should be characterized and calibrated using SI traceable standards. In the case of earth remote sensing, this allows inter-comparison and intercalibration of different sensors in space to create global time series of climate records of high accuracy where some inevitable data gaps can be easily bridged. The recommended best practice guidelines for this pre-launch effort is presented based on experience gained at National Institute of Standards and Technology (NIST), National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA) programs over the past two decades. The currently available radiometric standards and calibration facilities at NIST serving the remote sensing community are described. Examples of best practice calibrations and intercomparisons to build SI (international System of Units) traceable uncertainty budget in the instrumentation used for preflight satellite sensor calibration and validation are presented.

Water Well Hydrographs: An Underutilized Resource for Characterizing Subsurface Conditions.

Many of the world's major aquifers are under severe stress as a result of intensive pumping to support irrigated agriculture and provide drinking water supplies for millions. The question of what the future holds for these aquifers is one of global importance. Without better information about subsurface conditions, it will be difficult to reliably assess an aquifer's response to management actions and climatic stresses. One important but underutilized source of information is the data from monitoring well networks that provide near-continuous records of water levels through time. Most organizations running these networks are, by necessity, primarily focused on network maintenance. The result is that relatively little attention is given to interpretation of the acquired hydrographs. However, embedded in those hydrographs is valuable information about subsurface conditions and aquifer responses to natural and anthropogenic stresses. We demonstrate the range of insights that can be gleaned from such hydrographs using data from the High Plains aquifer index well network of the Kansas Geological Survey. We show how information about an aquifer's hydraulic state and lateral extent, the nature of recharge, the hydraulic connection to the aquifer and nearby pumping wells, and the expected response to conservation-based pumping reductions can be extracted from these hydrographs. The value of this information is dependent on accurate water-level measurements; errors in those measurements can make it difficult to fully exploit the insights that water-well hydrographs can provide. We therefore conclude by presenting measures that can help reduce the potential for such errors.

Sources of Differences in On-Orbital Total Solar Irradiance Measurements and Description of a Proposed Laboratory Intercomparison.

There is a 5 W/m(2) (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underfill the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here.

Ethnic patterns of Hodgkin's disease incidence among children and adolescents in the United States, 1973-82.

The descriptive epidemiologic findings were summarized on 1,109 patients (white, black, and Hispanic) under 20 years of age who were diagnosed with Hodgkin's disease as reported to the Surveillance, Epidemiology, and End Results ("SEER") Program of the National Cancer Institute from 1973 to 1982. Across all ethnic strata, incidence rates increased with advancing age at diagnosis, with white adolescents 15-19 years old exhibiting the highest rates (male, 3.67; female, 4.18). Gender difference among children 0-14 years of age was most evident in blacks (male:female ratio: 4.0 for blacks, 1.0 for whites). Highest adolescent:childhood ratios of incidence rates were noted for females (5.81 for whites and 8.29 for New Mexico Hispanics) and lowest, for Hispanic males (1.25, New Mexico; 2.15, Puerto Rico). Whites exhibited the highest percentage of the nodular sclerosis histologic subtype (65%) and Hispanics, the lowest (45%). Conversely, Hispanics had higher rates of histologic types associated with a poorer prognosis (mixed cellularity and lymphocyte depletion). These differing age and histologic patterns were consistent with previously described international patterns of disease occurrence. Analysis of secular trends for whites from 1969 to 1982 revealed relatively stable rates for youngest ages and male adolescents. Rates increased over time for white female adolescents, but the trend was not statistically significant.

Nucleic acid flow cytometry in large cell lymphoma.

Between 1978 and 1985, 140 patients with large cell lymphoma (27 follicular, 92 diffuse, 5 immunoblastic, and 16 transformed) had DNA-RNA cytometry performed on involved tissue. DNA-RNA features were correlated with treatment outcome and compared to other established prognostic factors in 63 newly diagnosed patients who received uniformly intensive therapy. Significantly better outcome was noted for previously untreated patients with intermediate RNA content (RNA index, 1.0-1.8), diploid DNA content, and (during the initial 12-month follow-up) low proliferative activity. Of patients followed beyond 12-24 months, those with high proliferative activity appeared to have the most durable remissions, although this was not statistically significant. These findings suggested a preferential impact of intensive chemotherapy on patients with intermediate RNA content and possibly those with high proliferative activity, since previous studies and our own experience with relapsing patients have indicated a progressively worse outlook with higher proliferative activity and RNA index values. In newly diagnosed patients, multivariate analysis identified RNA content as the most important prognostic factor, followed by proliferative activity and serum lactate dehydrogenase. Thus, for patients with large cell lymphoma, DNA-RNA cytometry appears to be a valuable prognostic parameter for identifying a subset of patients who have a high likelihood of cure with intensive chemotherapy.

Stage III follicular lymphoma: durable remissions with a combined chemotherapy-radiotherapy regimen.

From 1975 to 1982, 74 patients with stage III follicular lymphoma were treated with a combined modality protocol which included chemotherapy with cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin (CHOP-Bleo), and radiotherapy to involved regions. This program resulted in a complete remission (CR) rate of 81%, a 5-year survival of 75%, and 5-year relapse-free survival (RFS) of 52% for all patients. Analysis of potential factors affecting treatment outcome revealed a significantly better CR rate for patients with small cleaved cell type (97%) than for patients with mixed (73%) or large-cell (57%) histologies. The 5-year survival was significantly better for patients with small cleaved (91%) and mixed (84%) cell types than for large cell (40%). In addition, bulky abdominal disease and elevated serum lactate dehydrogenase (LDH) were significant adverse prognostic factors for CR and for survival. Toxicity was moderate. No secondary leukemias have occurred. This combined modality regimen resulted in prolonged remission and potential cure for over half of patients who achieved CR, and is particularly encouraging for those with follicular small cleaved and mixed histologies.

Discordant bone marrow involvement in diffuse large-cell lymphoma: a distinct clinical-pathologic entity associated with a continuous risk of relapse.

From 1975 to 1988, 50 patients with lymph node biopsy-documented diffuse large-cell lymphoma (DLCL) presented with bone marrow involvement. Twenty-four patients (48%) had large-cell lymphoma (LCL) in the bone marrow and were compared with 19 (38%) patients who had small cleaved-cell lymphoma (SCCL) in the marrow. Additionally, seven patients (14%) had mixed small- and large-cell lymphoma (ML) in the marrow. Patients who had LCL marrow involvement were younger (P less than .02) and more frequently had elevated lactic dehydrogenase (LDH) levels (P less than .001), high tumor burden (P less than .01), and more sites of extranodal disease (P less than .05) than those with SCCL in the marrow. The complete response (CR) rate to multiagent chemotherapy was 16.7% in the LCL group and 89.4% in the SCCL group (P less than .001). One third of the patients with LCL in the marrow developed CNS involvement, compared with only one patient in the SCCL group (P = .06). Overall 5-year survival was 79% in patients with SCCL marrow involvement, compared with only 12% in patients with LCL in the marrow (P = .002). Despite a high CR rate, patients with marrow involved by SCCL were at a high continuous risk of relapse with only a 30% failure-free survival at 5 years. We conclude that bone marrow involvement with LCL predicts for extremely poor prognosis with low response rate and short survival. Patients with SCCL in the bone marrow have a high rate of CR and a high rate of 5-year survival; however, there is a high risk of late relapse, and only 15% are in a continuous remission at 8 years.

Factors predicting for response and survival in adults with advanced non-Hodgkin's lymphoma.

Knowledge of the prognostic factors that characterize a disease can assist in planning and analyzing clinical trials. The present study was conducted to determine the characteristics related to response and survival in patients with stage III and IV non-Hodgkin's lymphoma who were treated with combinations of cyclophosphamide, vincristine sulfate, and prednisone. Considering each characteristic individually and using stepwise regression analysis, tumor bulkiness, prior therapy, sex, and pretreatment lymphocyte count were selected as the four most important prognostic variables. Tumor architecture (diffuse or nodular pattern) and cell type, hemoglobin level, and symptoms although not important in predicting response were found to be important in predicting survival. The hemoglobin level had only marginal importance in predicting response. Factors found not be important were age, stage, symptoms, cell type, nodularity, marrow involvement, prior extensive radiotherapy, and bone involvement. A logistic regression equation has been derived that can be used to predict response rate.

Bootstrap calibration and uncertainty estimation of downhole NMR hydraulic conductivity estimates in an unconsolidated aquifer.

Characterization of hydraulic conductivity (K) in aquifers is critical for evaluation, management, and remediation of groundwater resources. While estimates of K have been traditionally obtained using hydraulic tests over discrete intervals in wells, geophysical measurements are emerging as an alternative way to estimate this parameter. Nuclear magnetic resonance (NMR) logging, a technology once largely applied to characterization of deep consolidated rock petroleum reservoirs, is beginning to see use in near-surface unconsolidated aquifers. Using a well-known rock physics relationship-the Schlumberger Doll Research (SDR) equation--K and porosity can be estimated from NMR water content and relaxation time. Calibration of SDR parameters is necessary for this transformation because NMR relaxation properties are, in part, a function of magnetic mineralization and pore space geometry, which are locally variable quantities. Here, we present a statistically based method for calibrating SDR parameters that establishes a range for the estimated parameters and simultaneously estimates the uncertainty of the resulting K values. We used co-located logging NMR and direct K measurements in an unconsolidated fluvial aquifer in Lawrence, Kansas, USA to demonstrate that K can be estimated using logging NMR to a similar level of uncertainty as with traditional direct hydraulic measurements in unconsolidated sediments under field conditions. Results of this study provide a benchmark for future calibrations of NMR to obtain K in unconsolidated sediments and suggest a method for evaluating uncertainty in both K and SDR parameter values.

Cartilage formation in a hollow fiber bioreactor studied by proton magnetic resonance microscopy.

The ideal in vitro system for investigating the regulation of cartilage formation and maintenance would allow for three-dimensional tissue growth, a wide range of biochemical interventions, and non-destructive evaluation. We have developed a hollow fiber bioreactor (HFBR) system which meets these criteria. After injection with embryonic chick sternal chondrocytes, neocartilage is elaborated around the hollow fibers, reaching a thickness of up to a millimeter after four weeks of growth. This process was monitored over time with nuclear magnetic resonance (NMR) microimaging and correlative biochemical and histologic analyses. Tissue volume and cellularity increased greatly during development. This was accompanied by changes in magnetic resonance properties consistent with increased macromolecular content. Further, tissue heterogeneity, observed as regional variations in cell size in histologic sections, was also observed in quantitative NMR images.

Refractoriness to chemotherapy and poor survival related to abnormalities of chromosomes 17 and 7 in lymphoma.

PURPOSE: Lymphoma cells usually show cytogenetic abnormalities, but their relationship to prognosis has not been as extensively studied as in leukemia. A group of previously untreated cases of lymphoma with evaluable metaphases was examined for the association between cytogenetic abnormalities and clinical outcome. PATIENTS AND METHODS: The study consisted of 104 patients, from whom fresh tumor samples were obtained for cytogenetic tests. Because of the complexity of lymphoma karyotypes, the cases were divided into four patterns according to the type of abnormality of chromosome 17 or 7 present. Treatment of patients was given based on histologic grade and stage of disease. Response to treatment was evaluated according to previously described methods. RESULTS: Patients with true abnormalities of chromosome 17 or 7 (defined as those with either structural abnormalities of the short arm of these chromosomes or monosomy of these chromosomes with no associated unidentified markers) were observed to have an adverse prognosis. The overall response rate and tumor-related mortality were less favorable for patients with these cytogenetic abnormalities. By applying multivariate analysis, we found that this observation was independent of the effect of serum lactic dehydrogenase level, histologic grade, or tumor burden. CONCLUSION: True abnormalities of chromosome 17 or 7 in patients with lymphoma are associated with a poor response to chemotherapy, short time to treatment failure, and high tumor-related mortality rate. These findings raise the question of the potential involvement of some gene or oncogene, perhaps the p53 oncogene, which might impart a survival advantage to the malignant cells.

Hodgkin's disease: correlation of clinical characteristics with probabilities for negative lymphangiogram vs. negative laparotomy findings in patients with Stage I supradiaphragmatic presentations vs. those in patients with Stage II.

PURPOSE: At a time both when late complications and second malignancies have become a growing concern and when staging laparotomy has been largely abandoned and comparative studies for staging Hodgkin's disease by state of the art computed tomography (CT) vs. lymphangiography have revealed minimal differences in results for these procedures, our purpose for undertaking this study was twofold. Our initial reason was to determine and compare probabilities for negative abdominal findings for patients with Stage I presentations with those for patients with Stage II as determined by lymphangiography and subsequently by laparotomy for those patients who had negative lymphangiograms. Our second reason, being an extension of the first, was to create a resource that can be used in conjunction with other information for arriving at appropriate treatment decisions including giving either more or particularly less than standard institutional therapy and especially with respect to the abdomen. METHODS AND MATERIALS: Data on 714 patients with prelymphangiogram Stage I-II upper torso presentations of Hodgkin's disease were entered prospectively in our database between 1968 and 1987. Twenty-eight with lymphocyte predominant disease, who had both negative lymphangiogram and negative laparotomy findings and 17 with questionable diagnoses of lymphocyte-depleted or unclassified disease were excluded from subsequent analyses of 669 patients with nodular sclerosis (NS) and mixed cellularity (MC) diagnoses. RESULTS: Stage I: in final logistic models, negative lymphangiogram findings were associated strongly with a combination of no constitutional symptoms and nodular sclerosis histology, whereas negative laparotomy findings correlated strongly with a combination of no constitutional symptoms and female sex. Predicted probabilities depended on the ratios of favorable to unfavorable characteristics. Stage II: in final logistic models, negative lymphangiogram findings were associated strongly with a combination of no constitutional symptoms, nodular sclerosis histology, age <40 years, and <4 involved sites, whereas negative laparotomy findings correlated strongly with a combination of <4 involved sites and mediastinal disease. Predicted probabilities again depended on the ratios of favorable to unfavorable characteristics. CONCLUSION: This study demonstrated that probabilities for negative abdominal findings for patients with supradiaphragmatic presentations of NS and MC Hodgkin's disease depended on: 1) whether the disease presented as Stage I or as Stage II; 2) whether staging was limited to a lymphangiogram or whether it included a laparotomy; and 3) or whether the clinical features associated with the presenting stage and methods of staging were favorable or unfavorable.

Hypocellular paratrabecular foci of treated small cleaved cell lymphoma in bone marrow biopsies.

Because of the new drug combinations being used to treat follicular lymphomas, the small cleaved cell lymphomatous foci in bone marrow biopsies appear to be altered. They become progressively hypocellular and contain a few and sometimes no small cleaved cells within oligocellular paratrabecular fibrous foci. These hypocellular paratrabecular foci (HPF) (a) are a clue that deeper sectioning is necessary to determine whether there are diagnostic foci of residual involvement by small cleaved cell lymphoma, (b) may indicate that other portions of the patient's bone marrow still contain viable foci of small cleaved cell lymphoma, and further, (c) should alert the clinician to the possibility of recurrence of small cleaved cell lymphoma in subsequent bone marrow biopsies. A comparison of patients who developed HPF in one or more of their bone marrow biopsy specimens with those who did not indicates that the changes are related to combinations of chemotherapy other than CHOP-Bleo (cyclophosphamide, adriamycin, vincristine, prednisone, bleomycin). Eighty-one percent of patients who developed HPF had received additional chemotherapeutic regimens, whereas 75% of patients whose bone marrows did not contain HPF had received only CHOP-B. The older age of the HPF-negative patients (median age 64 versus median age 43 for HPF-positive cases) may reflect more aggressive chemotherapy in the younger age group. While HPF appear to reflect some increased chemotherapeutic cytotoxicity affecting the lymphomatous foci in bone marrow, they do not appear to predict for a longer survival or cure.

Clinical implications of progressive transformation of germinal centers.

Fifty patients whose lymph node biopsies showed reactive follicular hyperplasia with the presence of progressive transformation of germinal centers were evaluated for current status of health, prior or subsequent development of Hodgkin's disease, and etiology of the lymph node hyperplasia. Histologically, on a background of reactive follicular hyperplasia, the nodes contained one or more germinal centers showing progressive transformation. These were three to four times the diameter of the other germinal centers and composed predominantly of small, round lymphocytes admixed with scattered immunoblasts and occasional benign histiocytes. Clinically, the majority of these patients were young males presenting with an asymptomatic solitary enlarged lymph node. fifteen had prior Hodgkin's disease. Five had concurrent progressive transformation of germinal centers and lymphocytic predominance Hodgkin's disease (two of these also had a subsequent biopsy showing only progressive transformation of germinal centers). All are currently free of Hodgkin's disease at 1-21 years. The largest group of 31 patients had no prior or subsequent Hodgkin's disease. One of the 50 developed multiple myeloma. Recognition of this phenomenon is important so that it will not be misconstrued as recurrent Hodgkin's disease, as de novo Hodgkin's disease, or as follicular lymphoma, which occurred in 12 (24%) of the cases.

Proteinaceous lymphadenopathy with hypergammaglobulinemia.

Three cases of a morphologically distinctive "sclerosis" of lymph nodes are presented. Two patients experienced recurring lymph node enlargement with associated mild malaise over an extended period. The first patient had unilateral axillary lymph node enlargement, but was asymptomatic and died of chronic obstructive pulmonary disease 17 years later with no evidence of lymph node enlargement at autopsy. Each patient had at least transient hypergammaglobulinemia, one with elevated IgM and IgA, one with elevated IgM, and one (from 1958) not further analyzed. Lymph node biopsies revealed extensive deposition of eosinophilic material in all three patients. Identical changes in lymph nodes have been described in chronic diseases. The eosinophilic material may be related to amyloid, but differs from it histochemically and ultrastructurally. The relationship of this lesion to the few cases reported as amyloidosis presenting as lymph node enlargement is discussed. Malignant lymphoma with sclerosis is the most important consideration in the differential diagnosis.

Paraimmunoblastic variant of small lymphocytic lymphoma/leukemia.

We report 16 cases of a distinctive, biologically aggressive variant of small lymphocytic lymphoma/leukemia (SLL/L) that is characterized by the diffuse proliferation of cells normally comprising the pseudoproliferation centers (so-called paraimmunoblasts). Demographically, the patients differed in no significant regard from patients with SLL/L of usual type. Rapidly progressive, generalized lymphadenopathy was the dominant clinical finding in 15 of the 16 patients; one patient presented with symptoms related to lymphomatous involvement of the stomach and regional lymph nodes. Splenomegaly was observed in five patients. Seven patients, two of whom had a history of indolent-phase chronic lymphocytic leukemia, had an absolute lymphocytosis at diagnosis. In most patients, bone marrow involvement was noted at diagnosis. It consisted predominantly of small lymphocytic infiltrates indistinguishable from those observed in SLL/L of usual type; significant paraimmunoblastic infiltration was infrequent and generally occurred late in the disease course. Immunohistochemical and cytogenetic study further substantiated the hypothesized relationship of these cases to SLL/L. Findings included (a) coexpression of sIg and Leu-1 antigen in the majority of cases and (b) the presence of a t(11;14) (q13;q32) chromosome translocation in two of three cases with analyzable metaphases. Although treatment protocols were not uniform, follow-up data indicated an accelerated clinical course. Eleven patients have died of their disease between 3 and 39 months after diagnosis; the median survival was 28 months.

The value of immunophenotyping on paraffin sections in the identification of T-cell rich B-cell large-cell lymphomas: lineage confirmed by JH rearrangement.

Immunophenotyping of lymphomas using paraffin-embedded lymphoid tissue, not previously distorted by frozen section, is useful in identifying the large neoplastic B cells that may be in the minority in T-cell rich B-cell lymphoma (TCRBCL). Even in cases in which frozen tissue sections are available, the improved morphology in unfrozen sections allows the proper classification of these lymphomas as large cell and identifies their B-cell lineage, which is important for clinical therapeutic studies. Seven cases initially believed to be diffuse mixed cell lymphoma of possible peripheral T-cell lineage showed the large cells to be immunoreactive with L-26 (pan B-cell marker) with the majority of smaller lymphocytes immunoreactive for UCHL-1 and Leu-22 (pan T-cell markers). K/lambda immunostaining on frozen sections was equivocal. In these cases, the diagnosis of large-cell lymphoma of B-cell lineage was confirmed by detection of immunoglobulin heavy- (all seven cases) and light- (six of seven cases) chain gene rearrangements, with germ-line configuration of the T-cell receptor beta-chain gene (all cases). Some cases of TCRBCL may not show detectable rearrangement of the immunoglobulin genes because of the low concentration of neoplastic cells in the samples submitted. The presence of rearrangements in these seven cases, however, supports the diagnosis of TCRBCL based on paraffin immunophenotyping when frozen tissue is not available or when molecular studies are not feasible. Although these seven cases are classified as large-cell lymphoma, an intermediate-grade lymphoma, the influence of the reactive T-cell population on the clinical behavior will require follow-up studies.

Malignant lymphoma presenting as a renal mass: four cases.

Primary lymphoma of the kidney is extremely rare; most lymphomatous renal masses represent extension from adjacent sites of disease or involvement by generalized disease (4,9,12). Three men and one woman, 45 to 71 years of age, presented with solitary renal masses clinically thought to be renal cell carcinoma. Each experienced abdominal pain, one with hematuria and one with "B" symptoms. Physical examination revealed no peripheral lymphadenopathy or hepatosplenomegaly. Lactic dehydrogenase (LDH) was elevated in three cases, and blood urea nitrogen (BUN) and creatinine were slightly increased in two. Two cases were diagnosed correctly from needle biopsy, with ultrastructural confirmation in one case and marker studies, DNA flow cytometry, and cytogenetics in the other. Because of a presumptive diagnosis of renal cell carcinoma, two patients underwent nephrectomy. Three cases were large-cell lymphoma, and one, small noncleaved cell lymphoma.

Pancreatic acinar ectasia and intraoperative needle biopsy.

Intraoperative needle biopsy of the pancreas showing pancreatic acinar ectasia can present a problem in differential diagnosis from pancreatic carcinoma. Although this event has previously been described as an incidental postmortem finding, with the increasing use of intraoperative pancreatic biopsy, it is probable that it will be encountered more frequently. The surgical pathologist must be able to distinguish this entity from well-differentiated primary pancreatic adenocarcinoma on frozen section.