Author: Alina Bodnariu DVM MSc PhD FRCPath MRCVS

Case presentation

A 10-year-old Cocker Spaniel presented with a history of intermittent haematuria of five days duration. Rectal examination revealed an irregular, painful prostate gland. Ultrasound examination revealed a cystic and fibrotic prostate gland. A prostatic wash was performed, and the sample was submitted to NationWide Laboratories for evaluation.

Cytological and microbiology findings

The prostatic wash sample identified an atypical epithelial cell population with associated moderate mixed inflammation (neutrophilic and macrophagic). Moderate numbers of prostatic epithelial cell clusters were harvested. The cells had moderate to high N:C ratio, round to oval nuclei with clumped chromatin, small nucleoli and small to moderate amounts of light basophilic cytoplasm. Occasional binucleated and trinucleated cells were noted. There was moderate to marked anisocytosis and anisokaryosis. Moderate numbers of neutrophils and macrophages were admixed. Microorganisms were not found.

Culture of the prostatic wash was negative (no bacterial, yeast or fungal growth).

Cytological interpretation

The presence of atypical prostatic epithelial cells raised suspicion for epithelial neoplasia, however prostatic epithelial hyperplasia secondary to inflammation could not be ruled out entirely.

Ancillary tests

A BRAF mutation test was advised to investigate further for the possibility of prostatic carcinoma. This test was performed on the cytology slides and the V595E mutation was detected in the BRAF gene.

Discussion

The findings were considered consistent with a malignant epithelial neoplasia involving the prostate gland: urothelial carcinoma (transitional cell carcinoma) or prostatic carcinoma. Further classification of the neoplasia would require surgical biopsy of the prostate gland and histopathology examination, however the prostatic wash cytology examination and the BRAF mutation test were non-invasive tests that provided a diagnosis of malignancy in this case.