Serous fluids and washings: morphological and

immunohistochemical patterns in

reactive and neoplastic conditions

Prof. Ben Davidson, MD PhD, Department of Pathology, Norwegian Radium Hospital, Oslo

University Hospital, Oslo, Norway; Dr. Gareth Rowland, MB, BCh, FRCPath, University Hospital of Wales, Heath, Cardiff, UK

Disclosure/ Acknowledgement

Serous effusions

• Frequent clinical finding

• Pleural, peritoneal, pericardial

• May be the first presentation of malignancy or only site of

metastasis

• Far-reaching clinical implications

The main questions

• Is it benign or malignant?

• If benign, can we reach a specific diagnosis?

• If malignant, is it primary or metastatic? Diagnosis?

Differential diagnosis

• Primary tumors

Malignant mesothelioma

Primary peritoneal carcinoma

Hematological cancers

Sarcoma (rare)

• Metastases

Carcinomas

Other

Depending on

• Age and gender

• Previous history

• Other clinical findings

• Geography

Differential diagnosis

Davidson, Firat, Michael (eds.), Serous Effusions – Etiology, Diagnosis, Prognosis and Therapy (Springer 2011)

Is it epithelial (or epithelioid)?

Melanoma Sarcoma

And this?

Angiosarcoma Germ cell tumor

The pattern of the smear- revisited

The pattern of the smear- revisited

The pattern of the smear- revisited

The pattern of the smear- revisited

• Mesothelial atypia: Pulmonary infarct, pancreatitis, radiation,

chemotherapy, cirrhosis, heart failure, renal failure/uremia

Macrophages

Endometriosis

Ancillary methods

• EM

• IHC

• Flow cytometry

• PCR

• FISH

• Cytogenetics

• CGH and gene expression arrays

• NGS

Davidson, Firat, Michael (eds.), Serous Effusions – Etiology, Diagnosis, Prognosis and Therapy (Springer 2011)

Potential new markers

• PAX2

• Claudins

• BAP1

• MUC4

• CD24

• MMP7

• Tenascin-X