Squamous cell carcinoma in serous effusions: Avoiding pitfalls in this rare encounter

Practical Approach to Reporting Based on the International System for Serous Fluid Cytopathology

The International System for Serous Fluid Cytopathology (TIS) is intended for reporting cytological specimens from serous cavities: pleural, abdominal and pericardial cavities. TIS is being adopted into practice in cytology laboratories worldwide. In this system, there are six diagnostic categories: non-diagnostic, negative for malignancy, atypia of undetermined significance, suspicious for malignancy, malignant-primary and malignant-secondary. Malignant-primary category almost always implies malignant mesothelioma and malignant-secondary usually refers to metastasis from carcinoma but also to involvement of serous cavity by haematolymphoid and other malignancies. When evaluating effusion cytological specimen adequacy, the factors that must be considered are sample volume, cellular content and cellular preservation. In the diagnostic analysis and interpretation, it is helpful to consider systematically all basic cytomorphological components in a sample. The basic components are architecture, cell populations, cell size, cytoplasm, nuclei and background elements. One important requirement for a successful evaluation of an effusion cytological specimen is sufficient clinical and radiological information in a referral. Clinical information may guide ancillary testing. In the present review, we provide a practical and educational approach to reporting serous effusion cytology based on the TIS.

Malignant pleural effusion from a case of squamous-cell carcinoma of the oral cavity: Cytological detection of a rare outcome

Distant metastases from carcinomas of the oral cavity are rare. Detection of these metastasis are essential for staging and management of the patient. These tumours may metastasize to lung, liver, brain and bone; but pleural involvement by squamous-cell carcinoma is distinctly rare. We present a case of bilateral pleural effusion arising from distant metastasis of squamous-cell carcinoma detected on cytology.

Immunocytochemistry for diagnostic cytopathology-A practical guide

Cytological specimens, which are obtained by minimally invasive methods, are an excellent source of diagnostic material. Sometimes they are the only material available for diagnosis as well as for prognostic/predictive markers. When cytomorphology is not straightforward, ancillary tests may be required for a definitive diagnosis to guide clinical management. Immunocytochemistry (ICC) is the most common and practical ancillary tool used to reach a diagnosis when cytomorphology is equivocal, to differentiate entities with overlapping morphological features, and to determine the cell lineage and the site of origin of a metastatic neoplasm. Numerous immunomarkers are available, and some are expressed in multiple neoplasms. To rule out entities within a differential diagnosis, the use of more than one marker, sometimes panels, is necessary. ICC panels for diagnostic purposes should be customised based on the clinical context and cytomorphology, and the markers should be used judiciously to preserve material for additional tests for targeted therapies in the appropriate setting. This review offers a practical guide for the use of ICC for diagnostic cytopathology, covering the most commonly encountered non-hematolymphoid diagnostic scenarios in various body sites.

Greater specificity of p40 compared with p63 in distinguishing squamous cell carcinoma from adenocarcinoma in effusion cellblocks

Objective

Squamous cell carcinoma (SCC) rarely causes malignant effusions. Distinguishing between SCC and adenocarcinoma in effusion cytology can be a challenge. p63 and p40 have been frequently used to support squamous cell differentiation in both histological and cytological specimens. However, similar results in cytological preparations of effusion fluids have been rarely reported. This study was designed to assess the diagnostic value of p63 and p40 immunoreactivity for the differentiation of SCC from adenocarcinoma in malignant effusions.

Materials and Methods

Immunocytochemical staining of p63 and p40 was performed on thirty cellblock specimens, including ten malignant effusions carrying SCC and twenty malignant effusions showing adenocarcinoma. Any degree of nuclear staining was considered positive.

Results

Of the ten SCC cases, 100% tested positive for both p63 and p40, and most cases showed diffuse staining (>25% of tumor cells). The expression of p63 and p40 was detected in 4 (20%) and 2 (10%) of twenty adenocarcinoma cases, and the extent of staining was all focal (≤25% of tumor cells). The p63 reactivity showed 100% sensitivity, 80% specificity, 71% positive predictive value, and 100% negative predictive value for the differentiation of SCC from adenocarcinoma in malignant effusions. The sensitivity of p40 for SCC was 100%, the specificity was 90%, the positive predictive value was 83%, and the negative predictive value was 100%.

Conclusion

Although p63 and p40 are both useful markers for the diagnosis of SCC in malignant effusions, p40 is more specific than p63 in distinguishing SCC from adenocarcinoma.

Diagnostic impact of ascites cytology in 941 patients: malignancy rates and time of detection in ovarian cancer relative to other tumor types

BACKGROUND

Cytological analysis of ascitic fluid is an important tool for diagnosis, staging, and prognostic assessment in patients with cancer, but more detailed information is needed regarding malignancy rates and the time sequence in which ascites develops for different sites of cancer origin. Especially, an increased early tumor diagnosis may improve the acceptance for cytological examinations for the tumor patients in oncological practice.

METHODS

Ascites specimens from patients who were treated at Bayreuth Hospital from 2006 to 2015 were reevaluated retrospectively and correlated with clinical reports.

RESULTS

580 of all 941 ascitis specimens (61.6%) were from patients with malignancies with predominant appearance of gastrointestinal and gynecological tumors in 516/580 (89%) patients. Histologically, 549 (94.6%) were carcinomas, 23 (4%) hematological malignancies, 5 (0.9%) mesotheliomas and 3 (0.5%) were melanomas. Malignant ascitic fluid was noted in 298 of the 580 (51.4%) patients with cancer, thus the overall malignancy rate in the ascites specimens examined was 298/941 (31.7%). The most frequent malignancy rate for gynecological tumors we obtained in ovarian cancer with 85.7% and in the upper gastrointestinal tract with 77.8% for Barrett's carcinoma and 61,4% for gastric carcinoma. Regarding time of detection, malignant ascitic fluid was noted as a separate finding, prior or simultaneous to the histological diagnosis of cancer in 225/298 patients (75.5%). An outstanding earliest occurrence was found in ovarian carcinoma in 94.9% and in the gastrointestinal tract in pancreatic carcinoma in 66.7%.

CONCLUSIONS

Tumor staging was the main important clinical question in our single center study of ascitic fluid, especially for patients with gastrointestinal and gynecological malignomas. The highest malignancy rate and earliest time of tumor detection caused the leading importance for ovarian tumors in malignant ascitic fluid. Moreover, the application of immunostains in our study allowed in 75.5% of all tumor patients a correct initial diagnosis, which is important for further clinical therapy.