Biopsy Specimens

TRUS needle biopsy: the wide-bore needle cores (18 gauge) are counted and measured (in mm), submitted separately if labelled accordingly and processed for initial histological examination through three levels. Careful handling is necessary to avoid crush artefact. Cores may be painted with alcian blue so that they are easily visible on facing the paraffin block. When sectioning, intervening ribbons of unstained sections are usefully kept for ancillary immunohistochemical studies if required.

TURP chippings: are weighed and sampled according to laboratory protocol. Fourteen per cent of specimens will reveal an unexpected carcinoma (stage pT1) and the more tissue processed the higher the detection rate. The availability of serum PSA now means that the chances of missing a clinically significant carcinoma are reduced. The potential management of such a detected cancer should ideally be known to avoid a substantial waste of resource. If aggressive treatment (radical prostatectomy) might be considered, for example in a younger patient, all tissue is embedded and examined histologically, as is also the case if there is any clinical suspicion of malignancy.

Otherwise, initial sampling of TURP specimens is recommended along the following Royal College of Pathologists guidelines:

For 12 g or less of tissue, all is processed; for over 12 g, 12 g plus an extra 2 g for every 5 g of tissue in excess of 12 g should be processed. This will normally equate to approximately six to eight cassettes for the average case. The suggestion of scrutinising chippings for suspicious (yellow or indurated) areas is felt to be impractical. One level is examined from each block. If carcinoma (or high-grade PIN) is found, all tissue should be processed to give an accurate stage (pT1a tumour in < 5% of tissue resected; pT1b tumour in > 5% of tissue resected).

If there is a previous diagnosis of carcinoma of the prostate, only a small amount of tissue, say 6 g or four cassettes, need be embedded.

0 0

Post a comment