Australian Society of CytologyCase of the Month
November 2003 - Answer and Discussion
Metastatic large cell carcinoma of lung.
Answer
Atypical cells are present, however degeneration precludes a definite diagnosis.
(Not very helpful to the clinician)
BUT WAIT……
This patient had undergone a pericardial and pleural biopsy 6 months earlier for metastatic large cell carcinoma of lung. These showed features in keeping with large cell malignancy (probably poorly differentiated adenocarcinoma). Some cells were positive for mucin staining.
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| Pericardial biopsy | ||
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| Pleural biopsy | ||
When comparing the cells seen in the CSF with those in the biopsies it is reasonable to conclude that they are from the same tumour.
My point in presenting this case? It demonstrates the assistance given in knowing the past history of the patient and other tests performed, to arrive at a more helpful and definitive diagnosis, especially when the current specimen is degenerate.
Discussion
Approximately 28% of intercranial neoplasms are secondary tumours.
The presence of any “alien” cells in a spinal fluid, when the possibility of contamination has been eliminated, should suggest a metastatic neoplasm.
Almost all carcinomas and sarcomas have the capacity to metastasize to the brain and the meninges. Cancer of the lung and the breast with their tendency to disseminate haematogenously are the tumour types encountered most frequently in CSF.
The cell types of carcinoma causing frequent metastases are adenocarcinoma and undifferentiated carcinoma. In addition to forming clumps, the cells may have a columnar form with abundant cytoplasm and occasional vacuoles. Nuclei are eccentric and cell boundaries are distinct .
The cells are larger than the normal cells usually seen in a spinal fluid (lymphocytes) and these malignant cells may show degenerative changes since they have frequently been exfoliated for a long time.
References
- Bigner S.H: Chapter 18:476. Comprehensive Cytopathology. M Bibbo.
- Naib Z.M: Exfoliative Cytopathology. 3rd Edition. p530.
- Takahashi M. Colour Atlas of Cancer Cytology. 2nd Edition. p 391-392.
