Chapter 9 Answers to discussion questions

Serous effusions and peritoneal washings

9.1 Discuss methods for the removal of red blood cells from serous effusions.

Why should we remove red blood cells? There are many techniques, all with advantages and disadvantages. Discuss use of older methodology such as density, gradient, and newer LBC methods. Briefly describe principles of the techniques. Consider cost/time, etc.


9.2 Discuss identification of malignancy of unknown origin in serous effusions.

Briefly discuss identification of malignant cells that have identifiable features, such as small cell anaplastic carcinoma, squamous carcinoma, and melanoma. Is it possible to suggest primary site with morphology alone? Discuss use of immunocytochemistry. Suggest panels of antibodies. Are there any truly specific markers? ‘Identification of malignancy of unknown origin requires correlating clinical, cytological, and immunocytochemical findings’. Discuss this statement.


9.3 Compare and contrast cytological features of adenocarcinoma and malignant mesothelioma. How can immunocytochemistry complement cytological findings?

This is a challenging area diagnostically. Describe cytology of adenocarcinoma and mesothelioma. You could tabulate the features. You will find a lot of similarities between the two entities. Discuss the use of immunocytochemistry, and particularly using a panel approach in resolving this diagnostic dilemma.


9.4 Briefly discuss the causes and characteristics of a benign serous cavity effusion.

There are numerous causes including:, congestive heart failure, Liver cirrhosis, Severe hypoalbuminemia, Nephrotic syndrome, Acute atelectasis, peritoneal dialysis, obstructive uropathy, end-stage kidney disease, parapneumonic effusion due to pneumonia, infection (empyema due to bacterial pneumonia), trauma, autoimmune disorders, pancreatitis, rheumatoid (RA) pleurisy,or  SLE.

Cytological presentation is dependent on the cause. Non-specific prestaton include presence of reactive mesothelial cells, macrophages and varied number of inflammatory cells.

In acute infection the number of polymorphs predominates, and in conditions such as TB the fluid often includes only lymphocytes. In rare cases of the effusions due to RA or SLE the typical cytological features may be seen.


9.5 Discuss the indications for peritoneal washings cytology.

Peritoneal washings should only be used for assessment of patients who have been treated for ovarian and peritoneal malignancies. Presence of malignant cells in peritoneal washings up stages the tumour.

In many centres peritoneal washings are still carried out in the assessment of endometrial and  non-gynaecological cancers. This practice has been shown not to have any clinical significance.

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