An evaluation of exfoliative cytology in the diagnosis of bovine ocular squamous cell carcinoma

Abstract

Exfoliative cytology of the bovine eye was studied to assess its usefulness in the diagnosis of bovine ocular squamous cell carcinoma. In a pilot study, nuclear changes such as condensation of nuclear chromatin, prominent nucleoli, anisonucleosis, bizarre mitoses, multinucleation and increased nucleocytoplasmic ratios, were seen in smears prepared from histologically confirmed squamous cell carcinomas. These changes were not observed in smears of benign precursor lesions or normal eyes. The specificity of these nuclear changes was further tested by the examination of 104 lesions by both cytology and histology. For 90 of the 104 lesions, the histological and cytological diagnoses were in agreement. The major problems encountered were in obtaining the required suitably fixed diagnostic cell from some lesions. This occurred where 2 lesions co-existed, where lesions occurred on the third eyelid and where large infected lesions were sampled. Exfoliative cytology is considered a useful technique in aiding the differentiation of benign changes from early malignancies; when combined with clinical history and location and description of the lesion it should prove even more useful.