Cytological assessment of conventional transbronchial fine needle aspiration of lymph nodes.

OBJECTIVES: Transbronchial fine needle aspiration (TBNA) is a minimally invasive bronchoscopic technique that allows pathological examination of mediastinal and hilar lymph nodes. The aim of this study was to assess the cytopathological outcome of TBNA. METHODS: One hundred and eighty-seven patients who underwent TBNA of mediastinal and hilar lesions from May 2000 to June 2007 were reviewed. RESULTS: TBNA results were considered to be adequate if the cytological material revealed a malignant lesion or sufficient number of benign lymphoid cells. In the current study, 40 cases (21.9%) were reported as inadequate. When inadequate tests were excluded, the overall sensitivity and accuracy of TBNA in the diagnosis of malignant lesions were 83.5% and 88.0% respectively. The lowest sensitivity was noted in lymph node involvement by lymphoma. Regarding the workload associated with TBNA cytology, we found that the average number of conventionally prepared cytological slides per case was high (17 slides per case). CONCLUSION: Our results confirm that conventional TBNA is a sensitive and useful technique but it is relatively expensive and the protocols should be adapted to allow appropriate material to be collected for ancillary diagnostic tests.

A rare case of follicular thyroid carcinoma in ovarian struma.

Struma ovarii is a form of specialised mature teratoma, with predominantly mature thyroid tissue in an ovarian teratoma as seen in 2% of cases. Its malignant transformation is even rarer and is seen in only 5% of those cases. This 40-year-old female patient had an incidental finding of a pelvic mass during investigation of secondary amenorrhoea. She underwent a staging laparotomy and pelvic clearance. The histopathology revealed a bilateral mature teratoma of the ovary with follicular thyroid carcinoma in the right ovarian struma (malignant struma). A total thyroidectomy was performed followed by a whole body 31I scintigraphy which did not reveal any abnormal uptake of isotope. The patient remains well after four years and is being followed-up with serial serum thyroglobulin surveillance.

Expression of mesothelial markers in malignant mesotheliomas: an immunohistochemical evaluation of 173 cases.

OBJECTIVE: To see the distribution of Calretinin, thrombomodulin, CK5/6 and HBME-1 markers in various subtypes of mesotheliomas and extend the published data on this topic. The positivity of adenocarcinoma specific markers (CEA and BerEP4) in malignant mesotheliomas have also been evaluated. METHODS: Various markers in 173 cases of malignant mesotheliomas received over a period of 8 years were evaluated by immunohistochemistry. RESULTS: In majority of malignant mesotheliomas i.e., epithelioid and biphasic types, the positive staining patterns complement the gold standard histologic diagnosis. However, in a small minority mainly sarcomatoid variant, heavy reliance cannot be placed on these markers. CEA and BerEP4 are useful negative markers of mesotheliomas, although occasionally these are positive in clear cut mesotheliomas. CONCLUSIONS: Specificity of various markers in malignant mesotheliomas should be assessed according to histologic subtypes. The existing generation of markers is not reliable in diagnosis of sarcomatoid mesotheliomas. Fortunately this forms only a small group of mesothelial malignancy. In common epithelioid and biphasic variants calretinin, thrombomodulin, CK5/6, HBME-1 are sensitive positive markers whereas CEA and BerEP4 are negative markers of malignant mesotheliomas.

Liver regeneration: a comparison of in situ hybridization for histone mRNA with bromodeoxyuridine labeling for the detection of S-phase cells.

We developed an in situ hybridization technique for measurement of proliferative cell numbers through detection of histone mRNA in routinely fixed, paraffin-embedded tissue sections. Histone gene expression is coordinated with the cell cycle, and the increase in expression during S-phase permits unambiguous identification of cells undergoing DNA replication. Histone mRNAs were identified in routinely processed rat liver tissue by non-isotopic in situ hybridization with digoxigenin-labeled oligonucleotide probes. Specific hybrids were detected with alkaline phosphatase-labeled anti-digoxigenin antibody and visualized by BCIP-nitroblue tetrazolium indicator substrate. Unequivocal cytoplasmic labeling was observed in various cell types in the liver remnant during the first 72 hr after a two-thirds partial hepatectomy. The spatial and temporal patterns of histone labeling were almost identical to those obtained by staining with an antibody to bromodeoxyuridine. The identification of histone mRNA appears to be a reliable marker of the S-phase fraction, a technique with the further advantage that the tissue does not have to be first exposed to a nucleotide analogue. Hence, retrospective studies are possible. The probes can be applied to human and animal cells and tissues because the nucleotide sequences of histone genes are conserved.

The sensitivity of cytologic evaluation of pleural fluid in the diagnosis of malignant mesothelioma.

Pleural malignant mesothelioma (MM), which is an aggressive neoplasm with a high mortality, frequently manifests initially as pleural effusions. The sensitivity of cytologic examination for its diagnosis varies widely in literature and most of the figures are from earlier studies with conventional cytologic preparations. The objective of this study was to provide the current evidence on the role and sensitivity of cytologic examination of pleural fluid in the diagnosis of MM. We reviewed the cytologic findings in pleural effusions of a large series of histologically proven MM (234 cases) diagnosed in our institution between 2001 and 2008. Of all cases, 154 (66%) had cytologic material examined. A specific diagnosis of MM was rendered or suspected in 53% (79 patients). The lowest sensitivity (20%) was noticed in sarcomatoid MM cases. MM was favored over adenocarcinoma in 97% of patients with positive cytologic findings that have been confirmed with immunohistochemistry. In this series, five cases were inadequate and five cases were initially reported as atypical, whereas 65 cases (44%) were reported as negative for malignancy. On review of the cytology slides, only four cases were upgraded from benign to suspicious compared to four cases downgraded from suspicious to atypical but no significant improvement to the diagnosis could be made on revision. These data suggested that a cytologic diagnosis contributed useful information in patients with epithelioid and biphasic pleural MM. Limitations of the cytologic examination of MM should also be acknowledged.

Evaluation of touch preparation cytology during frozen-section diagnoses of pulmonary lesions.

BACKGROUND: Intraoperative frozen section (FS) examination in thoracic surgery is a reliable method for diagnosis and staging of pulmonary lesions and provides a valuable guide in directing the extent of the ongoing surgical procedure. However, the contribution of touch preparation cytology (TPC) to FS diagnosis remains unclear. Aim To assess the utility of routinely performed TPC during FS diagnoses of pulmonary lesions. METHODS: In this study FS and TPC for all patients who had undergone FS diagnoses of pulmonary lesions in a 6-year period were reviewed by two pathologists. RESULTS: A total of 155 consecutive patients underwent intraoperative FS procedure, and 110 of those cases had TPC available for review. TPC was diagnostic or contributory to FS diagnosis in 97 (88%) cases, and non-contributory in 13 cases, mainly due to low or inadequate cellularity. TPC provided useful information regarding tumour subtyping, but it was less sensitive in the diagnosis of mucinous neoplasms and was less specific in the assessment of bronchial resection margins. In granulomatous lesions with or without necrosis, TPC was diagnostic in 10 (91%) cases. In five cases (including four cases of tuberculosis), TPC was the only diagnostic tool since FS was not completed. In conclusion, TPC showed high sensitivity and specificity rates and was contributory to FS diagnosis of pulmonary lesions. TPC provides a fast, less-expensive method of diagnosis, utilises a minimal amount of tissue, and can save processing of fresh frozen tissues in certain situations such as tuberculous lesions.