ANATOMIC PATHOLOGY

 

Role of fluorescent microscopy in detecting Mycobacterium leprae in tissue sections

Nayak SV, Shivarudrappa AS, Mukkamil AS.

Authors compared the sensitivity of the fluorescent method with that of the modified Fite-Faraco method in the detection of Mycobacterium leprae in tissue sections. Fifty-six skin biopsies were obtained from patients having leprosy, particularly the paucibacillary type. Minor alterations were made in the deparaffinization and staining technique, as compared with Kuper and May's method, to obtain optimum fluorescence. Of 56 biopsies studied, 39 showed organisms by the fluorescent method and only 25 showed organisms by the modified Fite-Faraco method. The fluorescent method was found to be more advantageous than the modified Fite-Faraco method, particularly in paucibacillary cases. Fluorescent microscopy has the advantage of speed and ease of screening and reduces observer fatigue. Bacillary positivity rates were higher in the fluorescent method than in the modified Fite-Faraco method in each type of leprosy.

 Ann Diagn Pathol l7(2):78-81, 2003

  

OCT4: A Novel Biomarker for Dysgerminoma of the Ovary

Cheng, Liang, Thomas, Antoinette, Roth, Lawrence M, Zheng et al

 The prognosis and therapy for dysgerminomas are different from those of other ovarian tumor types, making accurate diagnosis imperative for patient care. OCT4 (POU5F1) is a transcription factor involved in the regulation of pluripotency during embryonic development. It can be detected in both pluripotent cells and other early germ cells. This study examines the expression of OCT4 in both dysgerminoma and nondysgerminomatous neoplasms involving the ovary. Formalin-fixed, paraffin-embedded cell blocks of 33 cases of dysgerminoma including 2 cases of gonadoblastoma associated with dysgerminoma and 3 cases of metastatic dysgerminoma, and 111 cases of nondysgerminomatous neoplasms involving the ovary were stained using the antibody against OCT4. All cases of dysgerminomas and gonadoblastomas were positive for OCT4 with strong nuclear staining. More than 90% of dysgerminoma cells in each case showed diffuse strong nuclear staining. In addition, 3 metastatic dysgerminomas also showed uniform strong nuclear staining. All nondysgerminomatous tumors (mature teratoma, 14; yolk sac tumor, 4; Sertoli-Leydig cell tumor, 15; granulosa cell tumor, 22; Brenner tumor, 3; carcinoid tumor, 4; struma ovarii, 2; fibroma, 5; thecoma, 1; serous adenocarcinoma, 5; endometrioid adenocarcinoma, 4; small cell carcinoma, 6; stromal sarcoma, 1; malignant lymphoma, 6; metastatic malignant melanoma, 1; metastatic carcinoid, 2; metastatic small cell carcinoma, 1; and metastatic lobular carcinoma of the breast, 1) were negative for OCT4, except for some cases of clear cell adenocarcinoma of the ovary. Four of 14 clear cell adenocarcinomas showed focal positive nuclear immunoreactivity for OCT4. OCT4 is a sensitive and relatively specific biomarker for the detection of dysgerminoma. It may also be useful in the diagnosis of gonadoblastoma, which contains similar cells and may be associated with dysgerminoma. OCT4 may aid in the detection of small foci of metastatic dygerminoma in extraovarian sites and may also help distinguish dysgerminoma from other primary and metastatic tumors of the ovary.

 American Journal of Surgical Pathology. 28(10):1341-1346, 2004.

Histologic Grade, But Not SYT-SSX Fusion Type, Is an Important Prognostic Factor in Patients With Synovial Sarcoma: A Multicenter, Retrospective Analysis

 Louis Guillou, Jean Benhattar, Franoise Bonichon et al

 PURPOSE: To assess the prognostic value of SYT-SSX fusion type, in comparison with other factors, in a population of 165 patients with synovial sarcoma (SS).

 PATIENTS AND METHODS: Data on 165 patients with SS (141 with localized disease at diagnosis) were studied retrospectively. The following parameters were examined for their potential prognostic value: age at diagnosis, sex, tumor site (extremities v proximal/truncal), size, histology, mitotic count, necrosis, histologic grade (Fdration Nationale des Centres de Lutte Contre le Cancer system), stage (1997 tumor-node-metastasis system classification), surgical margin status (assessed histologically), and fusion type (SYT-SSX1 v SYT-SSX2). Median follow-up time was 37 months (range, 2 to 302 months).

 RESULTS: Among those patients with localized disease at diagnosis, median and 5-year disease-specific survivals (DSS) for the SYT-SSX1 and SYT-SSX2 subgroups were 126 months and 67.4% versus 82 months and 63.2%, respectively (P = .12). Median and 5-year metastasis-free survivals (MFS) were 84 months and 54.2% for SYT-SSX1 versus 50 months and 47.6% for SYT-SSX2 (P = .76). Univariate analyses showed that high histologic grade (grade 3), high mitotic count ( 10 mitoses/10 high-power fields), stage III disease, size greater than 7 cm, tumor necrosis, and presence of areas of poorly differentiated morphology were significant adverse prognostic factors for DSS and MFS, whereas SYT-SSX fusion type, tumor histology (biphasic v monophasic), and patient sex were not. Age greater than 35 years adversely affected DSS but not MFS. In multivariate analyses, histologic grade was the most significant prognostic factor for both DSS and MFS.

 CONCLUSION: For patients with localized SS, histologic grade but not SYT-SSX fusion type is a strong predictor of survival.

 Journal of Clinical Oncology, 22, : pp. 4040-4050,2004

 

Value of Immunohistochemistry in the Diagnosis of Salivary Gland Tumors

Foschini, Maria P., Eusebi, Vincenzo

Salivary gland tumors are rare entities that may hide diagnostic difficulties. Immunohistochemistry is a useful tool in daily diagnostic work to evaluate diagnostic and prognostic features. Mucoepidermoid carcinoma (MEC) is characterized by a zoning pattern, with cytokeratin (CK) 7 present in the central part and CK14 and mitochondria in the peripheral part of the neoplastic nests. High proliferative activity and c-ERB-B2 expression may indicate poor prognosis. Salivary duct carcinoma (SDC) should be differentiated from metastatic breast carcinoma demonstrating an in situ component. Staining the basal membrane with collagen IV and laminin, and the basal cells with CK14 might be useful for this purpose. SDC frequently shows androgen receptor positivity, and a case of tumor regression with antiandrogen therapy has been reported. Acinic cell carcinoma is positive with low-molecular weight CK, and with lysozyme and amylase. Adenoid cystic carcinoma may show areas of dedifferentiation, evidenced by a high proliferative rate with Ki-67 and by the loss of myoepithelial markers. Epithelial-myoepithelial carcinoma shows markers of epithelial and myoepithelial differentiation. Among the latter, smooth muscle actin and calponin are the most frequently expressed.

 Pathology Case Reviews. 9(6):270-275, 2004.

  

HAEMATOPATHOLOGY

 Antiphospholipid antibodies in lymphoma: prevalence and clinical significance

Pusterla S, Previtali S, Marziali S et al

 To evaluate whether the presence of antiphospholipid antibodies in lymphoma patients influences their response to treatment, and their rate of thromboembolic complications, authors followed up 100 consecutive patients with different lymphomas, who underwent measurement of lupus anticoagulants and anticardiolipin antibodies at diagnosis. In all, 27 patients had lupus anticoagulants and/or anticardiolipin antibodies. This prevalence was significantly higher than in a group of 100 age- and sex-matched normal control subjects (8%; P=0.0008, odds ratio 4.25, 95% confidence interval, 1.82-9.92). At diagnosis, antiphospholipid-positive and -negative patients were similar with respect to age, sex, type and staging of lymphomas. During follow-up, the rate of thrombosis was significantly higher in patients with (5.1% patients/year) than without (0.75% patients/year) antiphospholipid antibodies. The two groups were similar with respect to relapse and death rate. In conclusion, antiphospholipid antibodies are associated with lymphomas. Their determination is useful to identify patients at high risk to develop thrombotic complications, but not to predict treatment outcome or disease prognosis.

 Hematol J 5(4):341-6,2004

  

Warm reactive autoantibodies: clinical and serologic correlations.

Wheeler CA, Calhoun L, Blackall DP.

 Warm reactive autoantibodies are encountered relatively frequently in tertiary care hospitals. We studied 100 consecutive patients with warm autoantibodies to correlate their clinical and serologic features. Study patients (56 male, 44 female) had various diagnoses and a mean age of 53.5 years (range, 3-90 years). Autoimmune hemolysis was documented in 29 patients; 20 patients (69%) in this subset had diseases classically associated with warm autoimmune hemolytic anemia (hematologic and autoimmune disorders). All study patients demonstrated IgG on their RBCs (direct antiglobulin test [DAT] reactivity range, microscopic to 4+); 49 also demonstrated C3 (reactivity range, microscopic to 3+). The DAT for IgG was 2+ or more in 25 (86%) of 29 patients with hemolysis; the DAT for IgG was 1+ or less in 45 (63%) of 71 patients without hemolysis. In patients with hemolysis, 21 (72%) of 29 had a DAT reactive for C3. These findings may be useful in determining the clinical significance of warm autoantibodies and the extent to which patients should be followed up for hemolysis.

 Am J Clin Pathol. 122(5):680-5, 2004

  

Potential laboratory misdiagnosis of hemophilia and von Willebrand disorder owing to cold activation of blood samples for testing

Favaloro EJ, Soltani S, McDonald J.

 To assess the potential for misdiagnosis of von Willebrand disorder (vWD) and hemophilia A while following current National Committee for Clinical Laboratory Standards (NCCLS) guidelines and consequent to a poorly recognized cold-activation phenomenon, processed 39 normal citrate-anticoagulated samples by standard procedures (reference) or stored at low (~4 degrees C) or ambient (~22 degrees C) temperature for 3.5 hours before centrifugation and processing. Samples were tested in parallel for several hemostasis factors, including von Willebrand factor (vWF). Similar results were obtained for all samples for factors II, V, VII, IX, X, XI, and XII. For factor VIII (FVIII) and vWF, only samples stored at ambient temperature had results comparable to reference sample results. In most cases, low temperature storage led to much lower results. Taking the lower reference limit as 50%, most would have been defined as "abnormal," and a misdiagnosis of vWD or hemophilia A could easily arise. ABO classification and age were associated with FVIII and vWF levels, but neither was associated conclusively with relative loss of plasma FVIII coagulant and vWF caused by the cold-activation phenomenon. We advise laboratories following current NCCLS guidelines not to store or transport whole blood samples for FVIII and vWF testing at 2 degrees C to 4 degrees C because of the risk of misdiagnosing vWD or hemophilia A. Storage and transport at ambient temperature seem acceptable and provide results comparable to freshly centrifuged samples.

 Am J Clin Pathol 122(5):686-92,2004

  

MOLECULAR PATHOLOGY

 Proteomics and the Haematologist

K. S. Rees-Unwin, G. J. Morgan, F. E. Davies 

Understanding haematological malignancies at the protein level is important as the development of targeted treatments must be based on knowledge regarding the molecular pathogenesis of the tumour, inherited genetic variation and the mode of action of drugs. 'Proteomics' describes the analysis of the entire proteome of a cell or tissue and incorporates multiple technologies including Western blotting, two-dimensional gel electrophoresis, mass spectrometry, and ProteinChip-based technology. Although there are a limited number of studies to date in haematology those performed highlight the potential future impact of these technologies in the discovery of novel markers, proteins associated with drug resistance and the identification of tumour biomarkers which may facilitate the development of a rapid diagnostic test easily applicable in the clinical setting. Rapid large-scale analysis of the proteome in normal pathways and disease offers the opportunity of identification of potential diagnostic/prognostic markers and proteins associated with the malignant phenotype.

 Clinical & Laboratory Haematology 26 : 77, 2004

  

Protein Arrays 

Protein molecules,rather than DNA or RNA, carry out most cellular functions. The direct measurement of protein levels and activity within the cell is likely to be the best determinant of overall cell function. Techniques are being developed to quantify the levels of all the proteins within a cell and to compare protein levels between different cell types. As would be expected, the studies have highlighted differences in protein subsets of normal cells and between normal cells and tumour cells. At the present time, protein arrays are poised to become a central proteomics technology, important both in basic research and commercially for biotechnology enterprises. It is well recognised that the complexity of the human proteome far exceeds that of the genome. When variables such as alternative gene splicing events and post-translational modifications are taken into account, the number of different molecular protein species in man is likely to be at least an order of magnitude greater than the number of genes, i.e. about 500,000 proteins. Proteomics investigations are at the leading edge of functional genomics today and the development of protein arrays reflects the realisation that functional genomics discoveries will depend heavily on progress in defining the expression of, and interactions among, proteins. Conventional proteome analysis by 2D gel electrophoresis and mass spectrometry, while highly effective, has limitations and in particular may miss many proteins of interest when expressed at low abundance. There is therefore an acknowledged need for other sensitive and more accessible high throughput technologies for protein detection, quantitation and differential expression analysis in health and disease. For this reason, protein arrays are generating enormous interest at the research and biotechnology levels.

 

Proteomics in Diagnostic Pathology

  

Profiling and Imaging Proteins Directly in Tissue Sections

 Pierre Chaurand, Melinda E. Sanders, Roy A. Jensen et al

Direct tissue profiling and imaging mass spectrometry (MS) provide a molecular assessment of numerous expressed proteins within a tissue sample. MALDI MS (matrix-assisted laser desorption ionization) analysis of thin tissue sections results in the visualization of 500 to 1000 individual protein signals in the molecular weight range from 2000 to over 200,000. These signals directly correlate with protein distribution within a specific region of the tissue sample. The systematic investigation of the section allows the construction of ion density maps, or specific molecular images, for virtually every signal detected in the analysis. Ultimately, hundreds of images, each at a specific molecular weight, may be obtained. To date, profiling and imaging MS has been applied to multiple diseased tissues, including human non-small cell lung tumors, gliomas, and breast tumors. Interrogation of the resulting complex MS data sets using modern biocomputational tools has resulted in identification of both disease-state and patient-prognosis specific protein patterns. These studies suggest that such proteomic information will become more and more important in assessing disease progression, prognosis, and drug efficacy. Molecular histology has been known for some time and its value clear in the field of pathology. Imaging mass spectrometry brings a new dimension of molecular data, one focusing on the disease phenotype. The present article reviews the state of the art of the technology and its complementarity with traditional histopathological analyses.

 American Journal of Pathology. 165:1057-1068,2004

BOTTOM LINE

The Case Report

B. D. Pujari

In the last decades of the past century, with rapid advances in clinical investigations and pharmacology, journals were flooded with investigatory and evidence-based medicine' papers rather than single case reports. These papers mainly aimed at defining precisely the role and place of diagnostic testing or therapy. The case reports and case series were blamed for emphasizing unproved information' and for `doing more harm than good'. Though considered the `weakest' or `lowest' level of evidence, the case reports often form the basis for many new researches. The case reports and case series promote the discovery of a new disease or a combination of diseases, unexpected (useful or harmful) effects of therapies, as well as the study of mechanism. And hence merit publication. Sometimes papers highlighting mistakes are also educative. A recent survey shows more than 140,000 case reports in Indexed journals from 1996 to 2000. In reality the case reports and case series complement evidence-based medicine. The following categories still reward attention:  

1. A unique case representing a new entity or syndrome
2. A case with unidentified association of two or more disorders
3. A case with a clinically important variation from the expected pattern
4. A case report revealing useful or adverse therapeutic effect

 Minor uncommon features of a common disease, cases already reported in series, cases with complex investigations with insignificant implications, unusual observations detected by accident but clinically of no use, additional minor adverse effects of a drug, simple age variations, etc do not warrant publication.

 The point to be remembered is that the case report must add new information either to change the concept or management in general.

 Indian J Surg 66:101-4,2004