Does microhistology improve the cytological diagnosis of liver and pancreatic tumours?

Guided percutaneous fine needle aspiration cytodiagnosis of the liver, retroperitoneum and pancreas was performed in 197 patients. In 42 cases, material left after the smears were prepared was embedded in paraffin wax for histological examination. Six liver tumours and seven pancreatic tumours were identified in this material. In two cases the diagnosis of liver cell carcinoma was made only after microhistological examination. Re-examination of the cytological material in both cases disclosed features of liver cell carcinoma which were underestimated in the first examination and diagnosed only broadly as cancer cells. On the other hand, in another case cancer cells were present only in the smear and absent in the microhistological preparation. Diagnosis of pancreatic tumours was generally not improved by microhistological examination. In one case cancer cells were present only in the cytological material. In another case a cytological diagnosis of suspected cancer was confirmed as adenocarcinoma by microhistology. The diagnosis of non-neoplastic material in the remaining 29 cases were identical by cytopathology and microhistology. It is concluded that the microhistology of needle aspirate material complements cytological examination and can refine diagnosis although it increases cost.