Transformation of hairy cell leukemia to high-grade lymphoma: a case report and review of the literature

The coexistence of hairy cell leukemia (HCL) and non-Hodgkin's lymphoma is extremely rare. In the few reports demonstrating such coexistence, the relationship between the 2 entities was mostly inconclusive. We report a case of HCL that transformed to large cell lymphoma. This case has been followed for more than 4 years with immunohistochemical, flow cytometric, and molecular genetic studies on multiple bone marrow biopsy specimens, a splenectomy specimen, and a lymph node biopsy. In our case, the immunophenotype and tartrate-resistant acid phosphatase stain confirmed that the large cell lymphoma was of HCL origin. The markedly increased Ki-67 staining (proliferation fraction) in the lymph node biopsy specimen compared to the earlier splenectomy specimen indicated the transformation of a low-grade leukemia to a high-grade lymphoma. The overexpression of p53 in the lymph node implies that p53 mutation was probably involved in the pathogenesis of HCL transformation.     

Evaluation of the tissue microarray technique for immunohistochemical analysis in rectal cancer

BACKGROUND: Immunohistochemical staining for tumor-associated proteins is widely used for the identification of novel prognostic markers. Recently, a tissue-conserving, high-throughput technique, tissue microarray, has been introduced. This technique uses 0.6-mm tissue core biopsy specimens, 500 to 1000 of which are brought into a new paraffin array block, which can be sectioned up to 100 times. METHODS: We evaluated the tissue microarray technique for immunohistochemical analysis in 20 rectal cancers. Immunohistochemical staining was performed for the proliferation marker Ki-67 and the tumor suppressor protein p53 in whole tissue sections and in tissue core biopsy specimens. RESULTS: The whole tissue sections were assessed by counting all cells in 10 high-power fields (x40), which resulted in a mean fraction of Ki-67-expressing tumor cells of 0.81 (range, 0.54-1.0). p53 expression assessed in whole tissue sections showed nuclear staining in 15 (75%) of 20 rectal carcinomas. For the tissue microarray technique, a median of 3 (range, 3-5) 0.6-mm tissue core biopsy specimens were studied from each of the 20 tumor specimens. The tissue microarray method gave a mean Ki-67 expression of 0.85 (range, 0.50-1.0) in tumor cell nuclei and showed p53 protein expression in the same 15 of 20 tumors as in the whole tissue sections. CONCLUSION: We conclude that the tissue microarray technique for immunohistochemical staining in rectal cancer yields staining of good quality and expression data for Ki-67 and p53 comparable to those obtained with whole tissue staining. The feasibility of tissue microarray thus enables time- and tissue-preserving studies of multiple markers in large tumor series.     

Proliferative rates of non-Hodgkin's lymphomas as assessed by Ki-67 antibody

The Ki-67 antibody, a monoclonal antibody that reacts with nuclei in actively proliferating cells, was used in an immunohistochemical study to assess the growth fractions of non-Hodgkin's lymphomas and related disorders. The lowest proliferative indices were found in small lymphocytic lymphoma/chronic lymphocytic leukemia and intermediate lymphocytic/mantle zone lymphoma. An intermediate proliferative index was seen in the follicular lymphomas and diffuse small cleaved cell and diffuse mixed cell lymphomas. A high index was seen in the diffuse large cell lymphoma and lymphoblastic lymphoma. The highest and most consistent proliferative index was seen in small noncleaved cell lymphoma. Cases of reactive follicular hyperplasia had a significantly higher proliferative index than those of follicular lymphoma. We conclude that the Ki-67 antibody has great utility in providing an estimate of the proliferative rate of non-Hodgkin's lymphomas. Prospective studies may show this information to have prognostic value independent of histologic classification.     

A comparison of nucleolar organizer region staining and Ki-67 immunostaining in non-Hodgkin''s lymphoma

Eighty cases of non-Hodgkin's lymphomas were examined independently using the monoclonal antibody Ki-67 and an argyrophilic method for the demonstration of nucleolar organizer regions. The evidence that Ki-67 immunoreactivity may be used as a marker of cell proliferation is described and the nature of nucleolar organizer regions reviewed. The proportion of tumour cells with nuclear Ki-67 immunoreactivity and the mean number of nuclear organizer regions are shown to be linearly related (r = 0.86, P less than 0.001) although some scatter was observed. These data suggest that the mean number of nucleolar organizer regions may reflect the cellular kinetics of a tumour. This study also provides further evidence supporting the thesis that the mean nucleolar organizer region score is related to the histological grade of non-Hodgkin's lymphoma. Ki-67 immunostaining and nucleolar organizer region staining would seem to provide comparable data, at least in non-Hodgkin's lymphoma, but the latter method has the advantage of being applicable to conventionally fixed and processed paraffin sections.     

Prognostic importance of DNA flow cytometry in non-Hodgkin''s lymphomas.

Eighty one cases of non-Hodgkin's lymphoma were examined by DNA flow cytometry, using fixed embedded histological tissue. The frequency of detection of DNA aneuploidy and the values for S phase fractions depended on the histological subtype and grade of lymphoma. Twenty two of the patients with low grade centroblastic/centrocytic non-Hodgkin's lymphoma had repeat biopsies. Eleven of these patients remained histologically and cytometrically stable, but the remaining eleven transformed into high grade non-Hodgkin's lymphoma. The mean value for the S phase fraction in the initial biopsy specimens from patients which transformed was higher than that for patients whose lymphomas remained stable (p less than 0.001). It is proposed that estimates of S phase fraction prospectively identify patients with low grade non-Hodgkin's lymphoma at risk from transformation.     

Localization of the cell proliferation and apoptosis-associated CAS protein in lymphoid neoplasms.

We have evaluated the expression and distribution of the cellular apoptosis susceptibility (CAS) protein in normal lymphoid tissue and malignant lymphomas. CAS protein, the product of the CAS gene, is associated with microtubules and the mitotic spindle. Immunohistochemistry with an antibody to CAS shows many CAS-positive cells in normal tonsils. The majority of strongly CAS-positive cells were localized to the dark zone of the follicles, whereas the mantle zone and interfollicular areas were essentially negative. Double staining for CAS and Ki-67 revealed co-expression of the two proliferation markers in approximately 85 to 90% of the CAS-positive cells. Different subtypes of lymphomas exhibited varying patterns of CAS expression. Low-grade non-Hodgkin's lymphoma generally revealed weak staining with CAS, with 10 to 60% of all cells being positive. In contrast, highly malignant non-Hodgkin's lymphoma and malignant cells of Hodgkin's disease displayed very strong CAS positivity, with staining of up to 80% of the atypical cells. Overall, the staining pattern of CAS and Ki-67 was superimposable within a particular lymphoma subtype. However, in all lymphomas we observed a significant fraction of CAS-positive normal and malignant lymphocytes that were Ki-67 negative, probably because they were momentarily noncycling cells. We conclude that a high expression of CAS correlates with proliferation of normal and malignant lymphoid cells. The fact that detection of CAS protein identifies a higher portion of proliferating and malignant cells than Ki-67 warrants further evaluation of CAS protein as a marker with a diagnostic potential.     

Growth fraction in non-Hodgkin's lymphomas and reactive lymphadenitis determined by ki-67 monoclonal antibody in fine-needle aspirates

The fraction of proliferation cells was analysed in fine needle aspirates from a series of 448 non-Hodgkin's lymphomas and 199 reactive hyperplasias using an immunoperoxidase staining with monoclonal antibody Ki-67. There was a good correlation between proliferation fraction and cytologic assignment to high and low grade lymphomas. Thus high grade lymphomas had a high median percentage of Ki-67 positive cells with a figure of 82.1 for lymphoblastic, 60.0 for immunoblastic, and 59.7 for centroblastic lymphomas. For low grade lymphomas the figures were 17.1 and 11.1 percent for centroblastic/centrocytic and CLL/immunocytoma, respectively. the fraction of proliferation cells in reactive lymphadenitis varied between 1–50% with a median of 11.5%. Analysis of Ki-67 positivity can accordingly not be used to differentiate benign from neoplastic proliferations. Within all lymphoma subgroups but lymphoblastic lymphoma, there was a marked variation in fraction of Ki-67 positive cells, which resulted in a certain overlap between high and low grade lymphomas. the results show that cells procured through fine-needle aspiration can be used to analyse the fraction of proliferating cells which contributes information about the growth rate of the individual tumours that can not be obtained through cytologic classification. © Wiley-Liss, Inc.     

Role of flow cytometry in the diagnosis of lymphadenopathy in children

To evaluate the combination of fine-needle aspiration (FNA) and flow cytometric immunophenotyping (FCI) in the diagnosis of lymphadenopathy in children, we reviewed a total of 71 FNA specimens from pediatric patients with persistent lymphadenopathy. Two cases were deemed inadequate. In the remaining 69 cases, 54 (78%) were diagnosed as benign lesions, 9 (13%) as Hodgkin's lymphoma, 4 (6%) as non-Hodgkin's lymphoma or leukemic infiltrate, and 2 as metastatic tumors. Of the 69 cases, 25 cases (38%) were diagnosed based on cytomorphology alone, 30 (43%) by combined cytomorphology and FCI, and 19 (28%) by surgical biopsy. In conclusion, FNA is an easy, safe, and reliable procedure in the diagnosis of lymphadenopathy in children. In difficult cases, FCI can be used to exclude non-Hodgkin's lymphomas.     

Growth fractions in human prostatic carcinoma determined by Ki-67 immunostaining

Until recently, [3H]-thymidine incorporation, DNA analysis by flow cytometry, and cell doubling times have been the main methods of studying tumour cell kinetics. All these techniques are laborious, expensive, and difficult to perform in a routine diagnostic laboratory. This study examined fresh frozen sections from 31 prostatic biopsy specimens with the hybridoma antibody Ki-67, a marker of proliferating cells, using a modified avidin-biotin-peroxidase complex technique. The percentage of glandular cells decorated by this antibody, representing the growth fraction, was determined for both benign and malignant samples. Benign prostatic glands showed an average Ki-67 score of 4 per cent, significantly less than the 16.3 per cent mean growth fraction found in prostatic carcinomas. There was a significant correlation between the tumour growth fraction as assessed by Ki-67 staining, and the histological grade. A positive correlation was also found between the Ki-67 score and the intensity of staining, and a definite trend was noted between the Ki-67 score and the tumour clinical stage. Ki-67 promises to be a useful marker in determining the prognosis of prostatic cancer.     

Fine-needle aspiration biopsy in the evaluation of lymphadenopathy associated with cutaneous T-cell lymphoma (mycosis fungoides/Sézary syndrome)

We studied the role of fine-needle aspiration (FNA) in the evaluation of lymphadenopathy associated with cutaneous T-cell lymphoma (CTCL) in 11 patients with lymphadenopathy and compared findings with corresponding histologic material. Molecular genetic analysis for T-cell clonality by polymerase chain reaction (PCR) was performed on all aspirates. Immunophenotyping was successful in 4 of 7 cases in which flow cytometry was attempted from the aspirated material. Cytologic evaluation of FNA samples correlated strongly with histologic rating of involvement based on numbers of atypical cerebriform lymphocytes in the nodal specimen. Of 7 nodal specimens with scattered or small groups of atypical cells in the background of dermatopathic lymphadenopathy (LN1-2), the cytologic diagnosis was interpreted as reactive in all instances. Of 4 specimens with highly suspect (LN3) or definite histologic involvement (LN4), the cytologic diagnosis was likewise suspect or malignant. The correlation between molecular genetic studies on FNA samples and studies on tissue was not significant; in 2 cases, a T-cell clone was detected in the nodal tissue sample but not in the FNA sample, suggesting undersampling. A T-cell clone was detected by PCR in 5 of 7 nodal specimens judged reactive by FNA biopsy or histologic assessment. FNA for cytologic and molecular genetic analysis is a useful method to evaluate lymphadenopathy associated with CTCL and may obviate the need for surgical biopsy.     

Improved detection of lymphoid cell surface antigens in tissues fixed in periodate-lysine-paraformaldehyde (PLP)

Stabilization of cell surface antigens and preservation of tissue morphologic characteristics are important for diagnostic immunologic studies. Current reports continue to regard unfixed frozen sections as the material of choice for immunoperoxidase studies of lymphoproliferative diseases. In this study, periodate-lysine-paraformaldehyde (PLP) is shown to be a valuable fixative for the improved detection of surface antigens in lymphoid tissue. In cases of non-Hodgkin's lymphoma and Hodgkin's disease, more frequent detection of diagnostic markers and ease of interpretation was demonstrated by use of PLP-fixed frozen tissue as compared with unfixed frozen tissue. Immunoglobulin staining was more easily interpreted in 30% of B-cell non-Hodgkin's lymphoma. In Hodgkin's disease, Ki-1 antigen, a diagnostic marker of Reed-Sternberg cells, was found in PLP-fixed tissue from two cases in which this antigen was not detected in corresponding unfixed frozen tissue. The authors have demonstrated that PLP-fixed tissue can be sent to a central reference laboratory at ambient or room temperature, avoiding the expense and inconvenience of transporting specimens on dry ice. The authors conclude that PLP fixation is the preferred method for immunopathologic study of human lymphomas.     

Improving fine needle aspiration to predict the tumor biological aggressiveness in pancreatic neuroendocrine tumors using Ki-67 proliferation index,phosphorylated histone H3 (PHH3), and BCL-2

IntroductionSurgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells.Materials and methodsA retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed.ResultsAfter excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs.All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains).Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs.ConclusionGrade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.     

Fine-needle aspiration cytology and immunocytochemistry of orbital masses

A series of 85 fine-needle aspiration (FNA) biopsies from orbital space occupying lesions of 82 patients are reviewed. A total of 32 benign lesions and 49 malignant lesions were conclusively diagnosed. In two cases the aspirates were insufficient for diagnosis. Of two cases, which were cytologically suspicious for lymphoma, a repeat FNA resulted in a conclusive diagnosis of lymphoma in one case, while the second case proved to be a pseudotumor on an open biopsy material. Of the 32 benign lesions seven were fibrosis, six pseudotumors, four epidermal cysts, four meningiomas, and three pleomorphic adenomas. The remaining cases included two hematomas, one granuloma, three inflammations, and one malformation. In 43 of 49 malignant tumors cytomorphology was corroborated with immunocytochemistry. Thirty five of these were low- or high-grade lymphomas, nine metastases, two sarcomas, two plasmacytomas, and one chloroma. All lymphomas were of B phenotype with monoclonal light chain expression. The rate of cell proliferation as measured by Ki-67 immunostaining varied between 4-25% and 30-80% for low- and high-grade lymphomas, respectively. These results confirm previous reports on the usefulness of FNA biopsy in diagnosing orbital masses and emphasize the value of immunocytochemistry in tumor characterization.     

DNA flow cytometry of follicular non-Hodgkin''s lymphoma.

S-phase fraction, an index of cellular proliferation, and DNA ploidy were measured by DNA flow cytometry in a retrospective study of lymph node biopsy specimens from 83 cases (before treatment) of follicular non-Hodgkin's lymphoma, Working Formulation categories B and C. The correlations between these measures and survival, clinical stage, symptoms and histopathological factors were investigated. Aneuploidy was rare (n = 16) and had no effect on length of survival or transformation to high grade lymphoma. The overall mean S-phase fraction was 3.6%; for the whole series increasing S-phase fraction was associated with decreased survival. A high S-phase fraction (more than 5%) in initial biopsy specimens was also associated with an increased risk of subsequent high grade transformation at relapse. There was no difference between the survival or proliferative activity of tumours composed of mainly small cleaved cells compared with those composed of mixed small and large cells. There was no difference in survival or proliferative activity between tumours showing a pure follicular growth pattern and those with a mixed follicular and diffuse growth pattern. Multifactorial analysis showed that an S-phase fraction of more than 5% and B symptoms were the most important factors determining survival in these follicular non-Hodgkin's lymphomas.     

Accuracy of diagnosis of malignant lymphoma by combining fine-needle aspiration cytomorphology with immunocytochemistry and in selected cases, Southern blotting of aspirated cells: a tissue-controlled study of 86 patients.

Fine-needle aspiration (FNA) cytology of lymph nodes in malignant lymphoma is fraught with difficulty. In certain clinical situations, cytology has been documented to be useful in patients with malignant lymphoma. The intent of our investigation was to determine the accuracy of a multiparameter approach in diagnosing lymphoma. We reviewed the results of FNA cytology combined with the immunocytochemistry and, in some cases, the Southern blots of aspirated cell suspensions obtained from 86 suspected lymphoma patients who subsequently underwent surgical biopsy of the aspirated site. In four cases, in which FNA was unable to retrieve sufficient material for diagnosis, the histology showed extensive fibrosis. When the FNA diagnoses were compared with the histologic diagnoses, the diagnosis concurred in 69 cases (56 malignant lymphomas, 12 reactive, 1 atypical lymphoid proliferation). There was one false-positive, six false-negatives, and eight cases diagnosed as atypical lymphoid proliferation. Overall accuracy was 91%. There were two types of false-negative cases: those in which a diagnosis of another malignancy or unspecified malignant neoplasm was made and those that were diagnosed as reactive when the histology showed lymphoma. In seven cases, the DNA rearrangement studies of the antigen receptor genes were successfully performed on the aspirated cells and were useful in establishing lineage and clonality of both B and T lymphoid cells. Our study indicated that the use of a multiparameter approach in the diagnosis of malignant lymphoma by FNA enhanced the accuracy of diagnosis of the non-Hodgkin's lymphomas. In Hodgkin's disease, no benefit was derived from the approach.     

Fine needle aspiration cytology diagnosis of malignant lymphoma and reactive lymphoid hyperplasia.

AIMS: To assess the diagnostic accuracy of lymph node fine needle aspiration (FNA) cytology to distinguish reactive lymphoid hyperplasia from malignant lymphoma, and to evaluate the contribution of ancillary techniques applied to cytological material. METHODS: Two hundred and seventy seven consecutive lymph node FNA specimens reported to be consistent with reactive lymphoid hyperplasia (n = 213) or suggestive/diagnostic of malignant lymphoma (n = 64) were reviewed. Follow up data were obtained by case record review or by histological correlation. The value of immunocytochemistry, in situ hybridisation for immunoglobulin light chain mRNA, and polymerase chain reaction (PCR) towards the final clinicopathological diagnosis was assessed in 92, 61, and 45 cases, respectively. RESULTS: Sixty one of 67 lymphomas and 207 of 209 reactive lymph nodes were accurately diagnosed by FNA cytology. There were six false negative aspirates including three cases of follicular lymphoma, two cases of Hodgkin's disease, and one chronic lymphocytic leukaemia. Two FNA specimens considered suspicious of lymphoma proved reactive on histology or clinical follow up. One metastatic small cell carcinoma was wrongly diagnosed as lymphoma. Ancillary studies contributed to the correct diagnosis in most cases although occasional misleading results were obtained, particularly with PCR. CONCLUSIONS: FNA cytology accurately distinguished reactive lymphoid hyperplasia from malignant lymphoma in 97% of cases. However, occasional wrong diagnoses occurred owing to sampling error or misinterpretation. Ancillary studies can be applied to cytological samples and contribute to the diagnosis in most cases.     

Primary non-Hodgkin's lymphoma and malakoplakia of the vagina: a case report.

The vagina is a rare site for both primary non-Hodgkin's lymphoma and malakoplakia. We report a case of concurrent diffuse large B-cell lymphoma and malakoplakia of the vagina in a 67-year-old woman presenting with a vaginal discharge and a vaginal mass. The patient had two biopsy specimens reported as showing malakoplakia only, followed by a third biopsy specimen 10 months later which was diagnosed as diffuse large B-cell lymphoma. Review of the first two biopsy specimens showed areas of histiocytes with Michaelis-Gutman bodies merging with areas of cells with slightly larger nuclei and more amphophilic cytoplasm. Immunohistochemistry for the B-cell marker L-26 (CD20) and polymerase chain reaction analysis of the immunoglobulin heavy chain gene were helpful in retrospectively distinguishing the population of diffuse large B-cell lymphoma from the areas of malakoplakia. The third biopsy specimen showed sheets of large atypical lymphoid cells characteristic of a large cell lymphoma. Malakoplakia has been described in association with a variety of cancers, and this is only the second report of malakoplakia associated with non-Hodgkin's lymphoma. Considering the rarity of these two entities in the vagina, it is unlikely that the association in this case is coincidental, raising the possibilities of an unusual reaction to the presence of lymphoma or a common pathogenesis such as underlying chronic inflammation. Epstein-Barr virus DNA was detected in the second biopsy specimen, suggesting a possible role in the pathogenesis of this lymphoma.     

Comparison of the diagnostic value of bone marrow biopsy and bone marrow aspiration in neoplastic disease

The Jamshidi-Swaim biopsy needle was utilized to perform 205 bone marrow biopsies, accompanied by simultaneous bone marrow aspirates, on patients with lymphoma, leukaemia, and a variety of solid tumours. There was no significant morbidity. There were 67 positive findings with biopsy and 42 with aspiration. The two techniques were complementary in Hodgkin's disease, non-Hodgkin's lymphoma, breast carcinoma, bronchogenic carcinoma, malignant melanoma, and in leukaemia. We have examined the bone marrow biopsies and aspirates with respect to the adequacy of the bone marrow biopsy specimen, the number of positive biopsies in the various categories of neoplasia, and the disparity of biopsy and aspirate, finding that 28 of the 67 positive biopsies (41.8%) had negative aspirates. These data and specimens obtained compared quite favourably with other series in which a modification of the Vim-Silverman needle was used.     

Primary diagnosis and REAL/WHO classification of non-Hodgkin's lymphoma by fine-needle aspiration: cytomorphologic and immunophenotypic approach

The Revised European American lymphoma (REAL) and World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) relies on the constellation of cytologic, phenotypic, genotypic, and clinical characteristics of NHL. For the most part, the classification does not rely on architectural pattern for classification of neoplasms. This classification makes it possible to diagnose and classify lymphomas by fine-needle aspiration (FNA). In this study, we attempted to evaluate the accuracy of FNA in diagnosing and classifying NHL within the context of the REAL/WHO classifications. Cases included only those in which FNA was the primary diagnosis, followed by a surgical biopsy for confirmation. Flow cytometry (FCM) for phenotyping was carried out whenever material was available. Two groups of pathologists were identified. Group A consisted of pathologists with background training in cytopathology and/or hematopathology (three pathologists). Group B consisted of experienced surgical pathologists with no training in cytopathology and/or hematopathology (four pathologists). Seventy-four cases were included in the study. FCM phenotyping was performed in 53 cases (71%). Large cell lymphoma constituted 63% of the cases. The remaining lymphomas included Burkitt's, small lymphocytic, lymphoblastic, follicle center cell, Ki-1, mantle cell, marginal zone, and natural killer cell lymphoma. The diagnosis of lymphoma was rendered for all cases. The correct classification was seen in 63% of the cases. Classification was more accurate in immunophenotyped than in nonimmunophenotyped cases (84% vs 33%; P = 0.00004). Group A pathologists showed higher incidence of proper classification than group B (80% vs 56%; P = 0.046). The diagnosis and classification of NHL can be achieved in a large number of cases on FNA material. This accuracy can be increased if cytomorphologic criteria are established for different entities of NHL aided by FCM for phenotyping.     

Comparative Ultrastructure of Needle Aspiration Biopsy and Surgical Resection Specimens of Lung Tumors

Ultrastructural examination affords conclusive evidence for classification of lung tumors. Tissue properly fixed for electron microscopy is not available in many cases, however. Ultrastructural diagnosis of resected specimens obviously follows, rather than directs, the surgical treatment. Fine-needle aspiration (FNA) of lung masses is recommended as a means to obtain lung tumor tissue for electron microscopy. Nevertheless, no comparison has been made between ultrastructural information gained from aspiration specimens and resected specimens. Electron microscopy was performed on transthoracic FNA specimens of 10 lung tumors for which surgical resection was subsequently performed. Glutaraldehyde-fixed specimens from FNA and surgical resection were prepared for electron microscopy according to routine procedures. Fixation of the FNA specimens was equivalent or superior to that of the resected specimens in 9 of the cases. Three of the FNA specimens contained necrotic as well as viable tissue. Features essential for diagnosis such as desmosomes, junctions, neurosecretory granules, intermediate filaments, glycogen, lipid, mucin, and microvilli were identifiable in both FNA and resected specimens. FNA specimens therefore yield a representative sample of the ultra-structural features of lung tumors when adequate cellular material is obtained. Use of a coaxial needle sampling technique with immediate microscopic assessment reduces the likelihood of retrieving only blood or necrotic tissue in the electron microscopy specimens.