TEP/TDM dans le diagnostic et la stadification des lymphomes

Histological subtypes of lymphomas are important because FDG uptake is much greater in aggressive than in indolent lymphomas and this, results in lower sensitivity of PET for the staging of indolent lymphomas. Staging is especially useful when treatment is changed according to staging. Staging with imaging methods has traditionally been performed using a CT scanner and has been based on the detection of nodal enlargement, an increased number of small nodes and in the presence of extranodal masses. However, CT is limited by its poor sensitivity in the detection of extranodal sites of involvement, in the identification of tumour involvement of normal size lymph nodes and in the differentiation between malignant and inflammatory enlarged lymph nodes. The uptake of FDG detected with PET images reflects metabolic activity rather than the size of the tissue masses, localizing tumoral activity in enlarged and in normal size lymph nodes. In the literature review that compares PET with CT, PET usually indicates more lesions than CT would and PET improves sensitivity without losing specificity. However, the majority of studies report that PET, improves the staging in a relatively limited number of patients (10-20%) and may change treatment in less than 10% of patients. Diagnostic accuracy of PET may improve with the use of hybrid PET/CT systems that combine metabolic and morphological imaging, in the same scanner and without moving the patient. This is a promising technique that will overcome the limitations of both modalities and may enhance diagnostic accuracy in lymphoma patients. This hybrid equipment allows the use of PET/CT with contrast-enhanced full dose CT (a diagnostic CT) instead of carrying out PET and CT on different days.     

Algorithm for a DNA-cytophotometric diagnosis and grading of malignancy

An algorithm for processing data on nuclear DNA content obtained cytophotometrically was developed (1) to obtain an objective discrimination between benign and malignant lesions in conventional cytologic smears secondarily stained according to Feulgen and (2) to obtain an objective degree of tumor malignancy on a continuous scale of malignancy grades. Investigations in 258 malignant tumors (95 malignant lymphomas, 52 uterine cervix carcinomas, 28 prostate carcinomas, 18 breast carcinomas, 45 malignant bone tumors and 19 larynx carcinomas) and in 74 benign lesions in these organs yielded a diagnostic accuracy of no false-positive, no false-negative and 21% suspicious diagnoses. The probability that "suspicious" cases were malignant was 81%. The overall diagnostic accuracy for non-negative cases thus amounted to 100%. Results in 95 patients with different malignant lymphomas and in 16 patients with squamous-cell carcinoma of the larynx demonstrated the prognostic validity of the DNA-grading system.     

Cytomorphology and immunocytochemistry of fine needle aspirates from blastic non-Hodgkin's lymphomas

Fine needle aspirates from 54 consecutive patients with primary or recurrent blastic (high-grade malignant) non-Hodgkin's lymphomas (NHLs) were analyzed by cytomorphology and immunocytochemistry. The cytologic diagnoses induced follicular center-cell-derived (centroblastic or anaplastic centrocytic) lymphoma (31 cases), immunoblastic lymphoma (11 cases), lymphoblastic lymphoma (9 cases) and histiocytic lymphoma (3 cases). Immunocytochemistry showed a B-cell phenotype of the neoplastic lymphocytes in all lymphoblastic lymphomas, 29 follicle center-cell lymphomas and 4 immunoblastic lymphomas. Four of the immunoblastic lymphomas were of T-cell origin while one case was not evaluable due to necrosis. A histiocytic origin was confirmed in two of the three cases that had a cytologic diagnosis of histiocytic lymphoma; the third case was shown by immunocytochemistry to be a true Ki-1-positive large cell lymphoma. Histologic and immunohistochemical analysis were performed on surgical biopsies from 18 patients. The results were in agreement with those on the fine needle aspiration (FNA) material in 14 cases. Three lymphomas could be phenotyped on aspirated material while marker studies on excised material were inconclusive. One lymph node aspirate contained mostly necrotic cells, which were unsatisfactory for adequate immunocytochemistry. However, sections from a removed tonsil from the same patient could be used for conclusive histology and phenotyping. In conclusion, the high diagnostic accuracy of combined cytomorphologic and immunocytochemical assessment of FNA samples validates the use of the technique in the diagnostic work-up of blastic (high-grade malignant) NHLs. In fact, the diagnostic accuracy seems so high that the technique can safely be used in the final diagnosis of blastic NHLs.     

Preoperative cytologic diagnosis of primary gastrointestinal malignant lymphoma

This report is based on the review and study of primary gastrointestinal malignant lymphomas as seen in cytologic brushing and washing specimens. During a period of 12 years (1970 to 1981), a total of 2,675 patients with malignant lymphoma involving the gastrointestinal tract were seen at Memorial Sloan-Kettering Cancer Center. Of these patients, 73 were diagnosed as having primary malignant lymphoma of the gastrointestinal tract. A total of 49 preoperative cytologic specimens obtained from 29 patients with histologically confirmed primary gastrointestinal malignant lymphoma were examined and are the basis for this study. Twenty-four patients had gastric primaries; three tumors were in the colon and two were small intestinal lymphomas. Thirty-three cytologic specimens taken from 25 patients were considered diagnostic for malignant lymphoma. A positive cytologic brushing was the only diagnostic preoperative specimen for 9 of the 29 patients. Combined cytologic and biopsy specimens provided a diagnosis of malignant lymphoma for 16 patients. Cytologic washings did not add to the diagnostic accuracy. The 29 cases of malignant lymphoma reviewed here were histologically subclassified as 23 large-cell, poorly differentiated and six small-cell, well-differentiated lesions. The cytomorphologic features of malignant lymphoma as observed in gastrointestinal specimens are outlined, and differential diagnoses are discussed. Clinicopathologic implications of the cytologic findings are considered.     

Accuracy of [18F]FDG PET/MRI for the Detection of Liver Metastases

Background

The aim of this study was to compare the diagnostic accuracy of [¹⁸F]FDG-PET/MRI with PET/CT for the detection of liver metastases.

Methods

32 patients with solid malignancies underwent [¹⁸F]FDG-PET/CT and subsequent PET/MRI of the liver. Two readers assessed both datasets regarding lesion characterization (benign, indeterminate, malignant), conspicuity and diagnostic confidence. An imaging follow-up (mean interval: 185±92 days) and/-or histopathological specimen served as standards of reference. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for both modalities. Accuracy was determined by calculating the area under the receiver operating characteristic (ROC) curve. Values of conspicuity and diagnostic confidence were compared using Wilcoxon-signed-rank test.

Results

The standard of reference revealed 113 liver lesions in 26 patients (malignant: n = 45; benign: n = 68). For PET/MRI a higher accuracy (PET/CT: 82.4%; PET/MRI: 96.1%; p<0.001) as well as sensitivity (67.8% vs. 92.2%, p<0.01) and NPV (82.0% vs. 95.1%, p<0.05) were observed. PET/MRI offered higher lesion conspicuity (PET/CT: 2.0±1.1 [median: 2; range 0–3]; PET/MRI: 2.8±0.5 [median: 3; range 0–3]; p<0.001) and diagnostic confidence (PET/CT: 2.0±0.8 [median: 2; range: 1–3]; PET/MRI 2.6±0.6 [median: 3; range: 1–3]; p<0.001). Furthermore, PET/MRI enabled the detection of additional PET-negative metastases (reader 1: 10; reader 2: 12).

Conclusions

PET/MRI offers higher diagnostic accuracy compared to PET/CT for the detection of liver metastases.     

Cytogenetics in malignant lymphoma.

There appear to be four primary areas of interest in the application of cytogenetic techniques to the study of malignant lymphomas: (1) the role of cytogenetics in the diagnosis of lymphoma in problem cases, (2) as an aid to the classification of malignant lymphomas, (3) whether specific chromosomal patterns will have prognostic significance for response to therapy or survival, and (4) the role of cytogenetics in staging of malignant lymphomas. A case of reactive lymphoid hyperplasia is reported in which cytogenetic studies demonstrated an aneuploid clone suggesting that cytogenetic abnormalities of lymphoma may precede the diagnostic histopathologic picture. The occurrence of 14q+ marker chromosomes in plasmacytic myeloma, plasma cell leukemia, malignant lymphomas, Burkitt's lymphoma, and ataxia-telangiectasia suggest that a common etiologic or pathogenetic mechanism may be present in some of these disorders. A preliminary pilot study of spleens removed at staging laparotomy for Hdgkin's disease suggests that cytogenetic studies may be able to detect Hodgkin's disease that is not apparent histologically. Further studies are required to provide answers to these areas of interest in cytogenetics in malignant lymphoma.     

Diagnostic value of EBUS-TBNA for lung cancer with non-enlarged lymph nodes: a study in a tuberculosis-endemic country

Background

In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET.

Methods

We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA.

Results

The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET.

Conclusion

In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred.     

Diagnostic Accuracy of PET/CT-Guided Percutaneous Biopsies for Malignant Peripheral Nerve Sheath Tumors in Neurofibromatosis Type 1 Patients

Background

Malignant peripheral nerve sheath tumors (MPNST) are one of the most frequent causes of death in patients with neurofibromatosis type 1 (NF1). Early detection is crucial because complete surgical resection is the only curative treatment. It has been previously reported that an ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) image with a T/L (Tumor/Liver) SUV_max ratio > 1.5 provides a high negative predictive value; however, it is not specific enough to make a NF1-related MPNST diagnosis. A formal proof of malignant transformation from a histological analysis is necessary before surgical excision because the procedure can cause mutilation. The objective of the present work was to investigate the effectiveness of and complications associated with PET/CT-guided percutaneous biopsies for an NF1-related MPNST diagnosis.

Methods

PET/CT-guided percutaneous biopsy procedures performed on 26 NF1 patients with a clinical suspicion of MPNST and a suspect lesion from a PET/CT scan (T/L SUV_max ratio > 1.5) were retrospectively evaluated. The localization of the suspected malignant site was determined using PET/CT. A stereotactic (ultrasonic and CT control) core biopsy technique was used with a local anesthesia.

Results

The first PET/CT-guided percutaneous biopsies enabled a pathological diagnosis for all of the patients (no "inconclusive " results were obtained), and no secondary procedures were needed. Among the 26 patients, the histopathological results from the biopsy were malignant in 17 cases and benign (BPNST with atypical cells) in nine cases. No complications from the diagnostic procedure were observed. A surgical resection was performed in 18 patients (seven benign and 11 malignant biopsies), removing the fine needle biopsy scar. In addition, six locally advanced/metastatic MPNST were treated with chemo/radiotherapy, and two BPNST had no progression after a follow-up of 14 and 39 months, respectively. The PET/CT-guided percutaneous biopsy gave 25 accurate diagnoses and one false negative (BPNST with atypical cells on the biopsy and MPNST on the operated tumor), resulting in a diagnostic accuracy rate of 96%. This false negative case may be explained by the high heterogeneity of the tumor: benign areas were contiguous with the malignant ones and associated with inflammation.

Conclusions

PET/CT-guided percutaneous biopsies are an effective and relatively non-traumatic procedure for diagnosis of NF1-related MPNST. It is the most reliable approach for early detection of MPNST.     

直径小于1 cm孤立性肺结节的18F-FDG PET/CT诊断研究进展

孤立性肺结节的鉴别诊断一直是胸部影像学的研究热点。早期且准确地鉴别肺内小结节的良恶性,对于患者治疗方案的确定以及随访情况的评估均具有重要的临床意义。~(18)F-FDG PET/CT在鉴别诊断恶性肿瘤方面具有明显优于其他传统检查的高特异性和高敏感性,其公认的恶性肿瘤的诊断阈值是最大化标准摄取值(maximum standard uptake value, SUVmax)为2.5,然而部分临床数据显示一些直径小于1 cm的恶性肺结节的SUVmax数值小于2.5。因此在早期研究中,~(18)F-FDG PET/CT在诊断直径较小的肺结节的其临床价值仍存在争议。为了尽量降低SUVmax的测量误差,提高~(18)F-FDG PET/CT诊断的准确率,衍生出了许多SUVmax辅助诊断方法以及优化的重建算法、放射性显像剂的联合应用等手段。本文将对~(18)F-FDG PET/CT鉴别诊断直径小于1 cm孤立性肺结节的研究进展进行综述。     

Molecular genetic analysis in the diagnosis of lymphoma in fine needle aspiration biopsies. II. Lymphomas versus nonlymphoid malignant tumors

The configurations of immunoglobulin genes and T-cell receptor beta chain genes were analyzed by Southern blotting in DNA derived from nonlymphoid malignant tumors and lymphomas. Gene rearrangements were not detected in any of the 35 cases of nonlymphoid malignant tumors. On the contrary, they were shown in all 14 cases of non-Hodgkin's lymphomas, 2 of 3 cases of Hodgkin's disease and 2 cases diagnosed as non-Hodgkin's lymphoma or angioimmunoblastic lymphadenopathy. The differentiation by light microscopy between lymphoma and nonlymphoid malignant tumors was a diagnostic problem in five cases; the molecular genetic analysis of DNA was contributory in all five diagnostically difficult aspirates. By gene rearrangement studies, the diagnosis of lymphoma was confirmed in two cases and nonlymphoid malignant tumors were accurately indicated in aspirates diagnosed finally as rhabdomyosarcoma (one case) and carcinoma (two cases).     

Cytodiagnosis of malignant non-Hodgkin's lymphomas in effusions (author's transl)

Body cavity effusions in malignant non-Hodgkin's lymphomas, particularly in the early stages of those neoplasms, are rare in comparison to the far more common effusions in other malignant diseases and in inflammatory processes. Therefore, the cytological differential diagnosis is of great importance. Of 7,000 pleural and 1,700 ascitic effusions, only 42 cases were malignant non-Hodgkin's lymphoma and in 30 lymphoma was suspected. When lymphoma is suspected, particularly low-grade lymphoma, there are great difficulties in making a differential diagnosis. Using the more or less typical cellular and nuclear criteria of the various lymphoma types, an attempt was made to classify the unequivocal lymphomas according to the Kiel classification of malignant non-Hodgkin's lymphomas. In principle these criteria are the same in cytological and histological examinations. In 31 cases the lymphoma subtype could be specified and confirmed in part by subsequent histological examination. Apart from the suspect lymphoma cases (40%), cases of a low grade of malignancy were predominantly observed (28%). Lymphomas with a high grade of malignancy were less frequently encountered (15%), a proportion similar to that of unclassifiable lymphomas (16%). Apparently the cytological and karyological criteria are not yet adequate to classify lymphomas from conventionally prepared cytological specimens with a higher degree of accuracy.     

Diagnostic accuracy of cytology and immunocytology in carcinomatous effusions

Background: Immunocytology substantially improves the diagnostic accuracy of conventional cytology in the diagnosis of carcinomatous effusions. Due to the unequivocal characterization of the various cell populations, a sensitivity of 92% and specificity of 100% was achieved by immunocytology, examining samples of 1234 serous effusions. Objective: Cytology plays a central role in the aetiological clarification of serous effusions. The sensitivity of this method for the diagnosis of carcinomatous effusions varies between 40% and 80%. The aim of the present study was to investigate whether immunocytology substantially improves the diagnostic quality of the cytological examination in the diagnosis of carcinomatous effusions. Method: Consecutive serous effusions were examined by conventional cytology and by immunocytology. The immunocytological examination was performed on smears, using a standard panel of three antibodies against pancytokeratin, human epithelial antigen 125 and calretinin. Results: Altogether, 1234 effusion samples were examined. A total of 603 effusions were caused by carcinomas, five by malignant mesotheliomas, 11 by malignant lymphomas and 615 by non‐malignant disorders. In conventional cytology, carcinomatous effusions were correctly diagnosed in 314 samples, corresponding to a sensitivity of 52%. In 31 specimens (5%) tumour cells without further specification were described and in 161 samples (27%) the presence of tumour cells was suspected (84% overall sensitivity). A total of 97 carcinomatous effusions (16%) were diagnosed false‐negatively and 50 (8%) of the 615 non‐malignant effusions false‐positively (92% specificity). In immunocytology, 561 carcinomatous samples were correctly diagnosed, representing a sensitivity of 93%. In six cases (1%) the presence of tumour cells was suspected. A total of 36 carcinomatous effusions (6%) were diagnosed false‐negatively (94% over‐all sensitivity). Out of the 615 non‐malignant specimens, there were no false‐positive diagnoses (100% specificity). Conclusion: Immunocytology is a simple, cost‐effective, routinely practicable method which substantially improves the diagnostic accuracy of conventional cytology in the diagnosis of carcinomatous effusions. Therefore, we recommend the use of immunocytology in all those cases where cytology on its own is not completely unequivocal.     

The diagnostic value of on-site cytopathological evaluation and cell block preparation in fine-needle aspiration cytology of liver masses

OBJECTIVE: The aims of this study were to evaluate the typing accuracy of conventional smear (CS), cell block (CB) preparations and combined use of both procedures (CS + CB) for the diagnosis of hepatic malignancies and to determine whether immediate on-site cytopathological evaluation improves the diagnostic yield of liver fine-needle aspiration cytology (FNAC). METHODS: Ultrasound-guided FNABs were performed on 323 consecutive cases with liver masses between December 2002 and December 2004. Histologically and/or clinically correlated 167 cases were included in the study. Preliminary FNAB results, results of CS, CB, and combined use of CS and CB were compared regarding diagnostic sensitivity, specificity, and accuracy for the diagnosis of malignancy. Subtyping accuracies of different methods were also compared. RESULTS: The sensitivity of on-site cytopathological examination and CS were both 92.8%. The sensitivity of CS + CB was slightly better than that of CB (93.5% versus 84.8%). Specificity of all procedures was achieved 100%. Diagnostic accuracy of on-site cytopathological evaluation, CS, CB, and CS + CB were 93.9%, 93.9%, 87.2%, and 94.5%, respectively. A specific subtype diagnosis of malignant tumours could be rendered accurately on the basis of preliminary diagnosis in 71%, CS in 75.4%, CB in 78.3% and combined approach in 92% of cases. In terms of typing accuracy, 87.5% of HCCs, 93.2% of adenocarcinomas, 92.3% of neuroendocrine carcinomas, 100% of lymphomas and 100% of other malignant tumours were correctly subclassified in the final cytopathological diagnosis. The agreement between preliminary diagnosis and final cytopathological diagnosis was 77.2%. CONCLUSION: With use of on-site cytopathological evaluation and combined use of CS and CB, the diagnostic accuracy of liver tumours approaches 100% and also significantly improve diagnostic and subtyping accuracy of liver malignancies.     

Cost-effective PET investigations in oncology

The authors have reviewed the financial considerations of oncological FDG PET examinations by the guidelines of the Health Care Financing Administration (USA). By critical assessment of large number of clinical investigations,the cost-effectiveness of FDG PET scans has been confirmed in the following cases: differential diagnosis of solitary pulmonary nodule, diagnosis,staging and restaging of non-small cell lung cancer, colorectal cancer, malignant lymphomas, melanoma malignum, esophageal neoplasms and cancers of the head and neck. The role of this method in breast cancer is currently under intensive investigation. Due to the correct staging, PET examinations in these indications enable the clinicians to choose the optimal treatment ensuring the maximum probability of recovery and being cost-effective as unnecessary medical interventions become avoidable.     

Carcinoembryonic antigen in effusions. A diagnostic adjunct to cytology

A total of 189 effusion specimens (100 benign and 89 malignant) submitted for cytologic examination were assayed for carcinoembryonic antigen (CEA) by an enzyme immunoassay to determine whether the addition of CEA evaluation to cytologic study would improve the diagnostic accuracy for the detection of malignancy. The sensitivity and specificity were 78% and 90%, respectively, for a cytologic diagnosis of malignancy and 68% and 99%, respectively, for a positive CEA (greater than 5 ng/mL). CEA assay was negative in the most common epithelial malignancies of the female genital tract (15 of 17 cases), mesotheliomas (5), lymphomas (7) and alveolar-cell carcinoma of lung (1). CEA assay was positive in 55 of 89 cases of malignancy, including 14 cases with cytologically negative malignant effusions. The CEA assay sensitivity for lung carcinoma (95% for adenocarcinoma, 100% for oat-cell carcinoma and 100% for carcinosarcoma), breast carcinoma (95%), and gastrointestinal carcinoma (100%) were all over 90%. No significant difference in the levels of CEA was noted between gastrointestinal and lung adenocarcinomas. Oat-cell carcinomas and squamous-cell carcinomas had lower values. In cases of an effusion with an unknown primary, an elevated CEA in the fluid is diagnostic of metastatic carcinoma arising from the breast, lung or gastrointestinal tract.     

Cytochemical examination of acid phosphatase and beta-glucuronidase enzymes in low-grade B cell non-Hodgkin's lymphomas

The differential diagnostic significance of acid phosphatase and beta-glucuronidase were studied in 77 cases of low-grade B cell non-Hodgkin's lymphomas. In most cases the results of cytochemical enzyme studies performed on malignant cells of the bone marrow were evaluated. B cell chronic lymphocytic leukaemia, centrocytic and centroblastic/centrocytic lymphomas were characterized by a weak or a negative acid phosphatase and beta-glucuronidase activity. Stronger positivity was observed in immunocytoma and in Waldenstr?m's macroglobulinaemia, while the highest activity was found in multiple myeloma. Hairy cell leukaemia of B cell origin showed intensive tartrate-resistant acid phosphatase activity. The cytochemical examination of these lysosomal enzymes may be useful in the diagnosis of low-grade malignant lymphomas of B cell origin by completing other methods.     

Diagnostic Performance of Magnetic Resonance Cholangiopancreatography in Malignant Obstructive Jaundice

Malignant obstructive jaundice is caused by tumors arising from the head of the pancreas and biliary tree, or seen due to secondary metastases in the porta hepatis lymph nodes. Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive diagnostic technique that can be used for imaging the entire biliary tree and pancreatic duct system. The objective of this study was to evaluate the accuracy of MRCP in the diagnosis of malignant obstructive jaundice. The methods used involved comparative review of the images obtained by using magnetic resonance imaging and MRCP as well as comparison between MRCP- and pathology-based diagnoses. The accuracy of MRCP-based diagnosis of malignant obstructive jaundice was analyzed. Our data show that the positive rate of anatomical diagnosis and the detection rate of bile ducts on the proximal side of obstruction are 100%. The diagnostic accuracy of malignant obstruction was 82.9%. MRCP was found to have high diagnostic specificity for determining the location and extent of obstruction. We, therefore, concluded that MRCP had significance for clinical diagnosis of malignant obstructive jaundice. The positive rate of localization diagnosis was 100%. Distinguishing the quality of obstruction was also important. The diagnostic accuracy of MRCP for malignant obstructive jaundice was remarkably higher.     

The pathogenesis of diabetes mellitus. Possible usefulness of spontaneous hyperglycemic syndromes in animals.

Systematic studies of the patterns of anatomic distribution, pathways of probable spread, and prognosis of the malignant lymphomas have been greatly aided by the development of new histopathologic classifications and the introduction of more sophisticated and precise diagnostic techniques, such as lymphangiography and laparotomy with splenectomy and retroperitoneal node biopsy. Concomitantly, megavoltage radiotherapy apparatus has made total-lymphoid radiotherapy feasible and practical, and the availability of a widening spectrum of chemotherapeutic agents has ushered in a new era of combination chemotherapy. Collectively, these diagnostic and therapeutic advances have already begun to yield a dramatic improvement in the prognosis of Hodgkin''s disease and the other malignant lymphomas.     

Flow cytometry as an accurate tool to complement fine needle aspiration cytology in the diagnosis of low grade malignant lymphomas

S. Schmid, M. Tinguely, P. Cione, H. Moch and B. Bode
Flow cytometry as an accurate tool to complement fine needle aspiration cytology in the diagnosis of low grade malignant lymphomas Objective: Diagnosis of low grade non‐Hodgkin B‐cell lymphomas on cytological material may be problematic and in the past frequently required lymph node excision. We analysed our experience of the value of flow cytometry (FC) as an additional tool for the diagnosis of lymphoproliferative processes in the setting of a university cytology division with a busy fine needle cytology service. Methods: Consecutive cytological specimens with FC over a period of 3 years were retrospectively analysed and correlated with histology and follow‐up if available. FC was performed with the following antibodies: CD3, CD4, CD8, CD2, CD7, CD19, CD5, CD10, CD23, lambda and kappa chains. Results: Of 299 probes (273 fine needle aspirations and 26 fluids from 285 patients), 179 cases (60%) were diagnosed as reactive, 91 cases (30%) as malignant or suspicious and 29 cases (10%) as inconclusive. The results of histological examination of the lymph nodes were available in 41 of 91 (45%) malignant or suspicious cases and in 13 of 179 (7%) reactive cytological diagnoses. Cytologically diagnosed malignancy was confirmed in all histologically examined cases. In 12 of 13 reactive cytological cases (92%), a benign process was diagnosed histologically. In 34 of 299 cases (11%) additional molecular investigations of B‐cell clonality or specific translocations were performed. The lymphomas most frequently diagnosed were follicular lymphoma and lymphocytic lymphoma, followed by mantle cell and marginal zone lymphomas. Correlation with histology showed a sensitivity of 98% and a specificity of 100% for cytology in our series. Conclusions: FC is an important additional tool in the cytological diagnosis of lymphoproliferative disorders. The combined approach has a high diagnostic value that allows a reliable subclassification of low grade B‐cell non‐Hodgkin lymphomas.     

胸部疾病FDGPET、PET／CT显像的假阳性和假阴性陷阱

^18F-FDGPET显像正在被越来越多用于临床鉴别良、恶性疾病,特别在胸部疾病的诊断中较传统影像发挥着更大的作用。然而,氟脱氧葡萄糖（FDG）不是肿瘤特异性显像示踪剂,由于存在设备显像精确度的局限,造成了它在一些脏器、组织和细胞中的生理性和病理性,特异性和非特异性的代谢摄取,也造成了假阳性和假阴性的产生。因此,熟悉这些假阳性和假阴性的结果,能帮助临床医生更加正确地解读PET影像的真实含义,避免误诊和漏诊。本文阐述了^18F-FDGPETPET／CT显像在多种胸部疾病中出现的假阳性和假阴性结果。