More than 95% of primary prostate cancers are adenocarcinomas, and this discussion is confined to patients with this diagnosis. In general, the degree of tumor differentiation and abnormality of histologic growth pattern directly correlate with the likelihood of metastases and with death. Because of marked variability in tumor differentiation from one microscopic field to another, many pathologists will report the range of differentiation among the malignant cells that are present in a biopsy (Gleason grade).[1,2]

When the cytopathologist is experienced in the technique, and the specimen is adequate for analysis, fine-needle aspiration of the prostate (usually performed transrectally) has been shown to have an accuracy of diagnosis equal to that of traditional core-needle biopsy.[3] Fine-needle aspiration is less painful than core biopsy and, therefore, can be performed as an outpatient procedure and at periodic intervals for serial follow-up. Controversy exists as to whether it is as reliable for grading purposes, particularly with grade range apparent in different fields.[4] Many urologists now use a bioptic gun with ultrasound guidance, which is relatively painless. The risk of complications with this technique is low. A transperineal, ultrasound-guided approach can be used in those patients who may be at increased risk of complications through a transrectal approach.[5] In a series of 670 men undergoing biopsy with an 18-gauge needle, the complication rate was 2% with only 4 patients requiring hospitalization.[6]

References

1. Gleason DF, Mellinger GT: Prediction of prognosis for prostatic adenocarcinoma by combined histological grading and clinical staging. J Urol 111 (1): 58-64, 1974.  [PUBMED Abstract]
   
   
2. Gleason DF: Histologic grading and clinical staging of prostatic carcinoma. In: Tannenbaum M: Urologic Pathology: The Prostate. Philadelphia, Pa: Lea and Febiger, 1977, pp 171-197. 
   
   
3. Ljung BM, Cherrie R, Kaufman JJ: Fine needle aspiration biopsy of the prostate gland: a study of 103 cases with histological followup. J Urol 135 (5): 955-8, 1986.  [PUBMED Abstract]
   
   
4. Algaba F, Epstein JI, Aldape HC, et al.: Assessment of prostate carcinoma in core needle biopsy--definition of minimal criteria for the diagnosis of cancer in biopsy material. Cancer 78 (2): 376-81, 1996.  [PUBMED Abstract]
   
   
5. Webb JA, Shanmuganathan K, McLean A: Complications of ultrasound-guided transperineal prostate biopsy. A prospective study. Br J Urol 72 (5 Pt 2): 775-7, 1993.  [PUBMED Abstract]
   
   
6. Desmond PM, Clark J, Thompson IM, et al.: Morbidity with contemporary prostate biopsy. J Urol 150 (5 Pt 1): 1425-6, 1993.  [PUBMED Abstract]