British Journal of Urology (1977), 49, 705-710

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Early Diagnosis of Prostatic Carcinoma: The Role of Transurethral Resection and R. C. B. PUGH Institute of Urology and St Paul’s Hospital, London E. P. N. O’DONOGHUE

The use of transurethral resection (TUR) in prostatic surgery has created problems for the histopathologist as discussed by one of us (R. C. B. P.) in a Presidential Address to the Section of Urology at the Royal Society of Medicine. The main function of the hlstopathologist in this setting is to confirm the diagnosis of carcinoma when it is suspected on clinical grounds or to exclude it in the clinically benign gland. In contrast to open prostatectomy specimens, correct anatomical orientation of TUR material is not usually possible. In routine practice the histopathologist can sample only a proportion of the tissue received because examination of all resected tissue is impracticable, especially if the excised gland is large. The diagnosis of carcinoma from TUR specimens is therefore to some extent a lottery subject to sampling errors at surgery if resection has been incomplete, and again at histological examination. An attempt has been made to resolve these difficulties by separation of tissue on an anatomical basis during resection and the submission of 3 specimens for histopathological examination. The primary objective was to assess the feasibility of an anatomical separation of tissue and thus more representative histological sampling of TUR specimens. The secondary objectives were to use thls technique to characterise prostatic calcinoma more accurately in terms of size and extent of the primary tumour and to attempt to increase the detection rate of early disease. Patients and Methods The study was carried out on 50 men undergoing elective transurethral prostatectomy for bladder outlet obstruction. The mean age was 66.4 k 8 years (range 44 to 88 years). Men with clinically apparent prostatic carcinoma underwent prostatic resection only when there was evidence of bladder outlet obstruction as shown by residual urine volumes or conventional urodynamic studies. During TUR the tissue was subdivided into 3 parts, 1 from each lateral area and 1 from the posterior area (Fig. 1). Particular attention was paid to resection of the posterior portion in the expectation that this would provide the most likely source of carcinoma. The technique of Barnes (1943) has been used, resecting first the lateral tissue on either side after definition of the bladder neck fibres posteriorally and then the posterior portion with careful evacuation of tissue on completion of each stage. This triple specimen technique does not add significantly to the operating time. Results

The mean weight of tissue at each resection was 25.5 g with a range of 8 to 95 g. The mean weights for each lateral specimen were 10 g and 10.2 g and for the posterior specimen 5.4 g (Table I). Carcinoma was the preoperative clinical diagnosis in 10 patients (Table 11). 3 of these were found to have benign disease on histological examination after TUR and follow-up transrectal needle biopsy. The 7 clinically neoplastic cases all had extensive disease with involvement of the Read at the 33rd Annual Meeting of the British Association of Urological Surgeons in Aberdeen, June 1977. 705

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posterior specimen and one or both lateral specimens in 6 and diffuse involvement of the posterior specimen only in 1.4 of the 7 had metastases in bone and 1 had histologically proven lymph node metastases. I n 2 the lymph nodes were not assessed. In only 1 of the 40 patients with a clinical diagnosis of benign disease was carcinoma found on histological examination after TUR. Again there was extensive involvement of all 3 specimens but skeletal studies were negative and the nodes were not assessed. Discussion The principal finding of this pilot study is that segregation and selection of tissue at TUR is of great help to the histopathologist. Firstly it ensures more representative sampling from all 3 areas. Secondly, if a small area of carcinoma is found on sampling the histopathologist can readily select more tissue from that specimen for further examination and assessment. The posterior specimen accounts for approximately one-fifth of the total and it is therefore entirely feasible to block it out completely for histological examination in the majority of cases. The chief advantage of this policy is that the histopathologist can assess the extent of the tumour within the prostate. This is more precise than rectal examination in the differentiation of small lesions with a good prognosis from more extensive disease and this information can help greatly in management (O’Donoghue et al., 1976). Rather surprisingly, only 1 unsuspected carcinoma was found in 40 cases-a rate of 2.5%. Although this low detection rate may reflect a high clinical index of suspicion in a unit with a special interest in prostatic carcinoma, it seems more likely that even this triple sampling technique is insufficient for the detection of small tumours. The value of detecting small lesions may of course be questioned in view of their favourable natural history but their detection is at least a ready confirmation that histological sampling has been adequate. The reported incidence of prostatic carcinoma at post-mortem examination is in the range of 14 to 24% which greatly exceeds the clinical incidence of the disease (Table Ill). It is clear that many of these are of such a

Fig. 1. Transverse section of prostate a t proximal margin of veru montanuni indicating subdivision of resected tissue into 3 separate specimens. A small area of carcinoma is present in the R postero-lateral area.

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Table I Weights of Triple Specimen Resections in 50 Patients Weights (grams)

Total specimen

R lateral

L lateral

Posterior

25-5 & 18.2 8-95

10,Ok 7.9

3-43

10.1k 7 . 4 3-37

5.4t4.9 0-1-22

1277

500

506

271

-

Mean and S.D. Range Totals

Table 11 Preoperative Clinical Diagnosis, Distribution of Tumour and TNM Classification in 50 Patients Clinical diagnosis

Histology

I

Lateral

Posterior

3B 10 Malignant

{7M

f 1

40 Benign

+ +

0

+

+

+

{r:

MI (3) N + (1)

T3NX M1 TONX MO

size that they can only be found by serial or step-section techniques which are impracticable as a routine procedure. The incidence of unsuspected lesions at prostatectomy in reported series is approximately half that of the post-mortem series (Table IV) and these rates are based largely on open prostatectomy. Denton, Choy and Valk (1965) reported a 6 % rate with routine histological examination of T UR specimens and a 21 % rate if step-section was used. Barnes and Ninan (1972) have shown that the detection rate of TUR can be increased by 20 % if tissue from the posterior and apical areas is selected for histological examination. The work of McNeal (1969) and of Blacklock (1974) on the internal anatomy of the prostate is relevant and may provide the explanation of these discrepancies (Fig. 2). In the adolescent male the true prostate is composed largely of a cone shaped central zone the long axis of which is formed by the ejaculatory ducts and a peripheral zone which lies both peripheral and caudal to the central zone like a funnel imposed on a cone. McNeal has shown that carcinoma arises predominantly in the peripheral zone. With ageing and the development of benign prostatic hyperplasia from pel iurethral glands the true piostate is compressed peripherally (Fig. 3). In this situation, our posterior specimen is derived principally from the central zone and our lateral specimens principally from benign hyperplastic tissue. Selection of tissue from the peripheral zone would seem to be essential to exclude the presence of carcinoma. The 3-stage technique reported here is inadequate for the diagnosis of small lesions and perhaps should be ieplaced by a 4-stage procedure. It is suggested that one should first resect a coneshaped area from bladder neck to veru and segregate this tissue into right and left lateral and posterior specimens (Fig. 4). The remaining tissue at the periphery and apex corresponds

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Adolescent prostate

Fig. 2. Central and peripheral zones in adolescent prostate. Redrawn after McNeal.

anatomically to the peripheral zone and resembles chords of a circle in coronal section. Resection of this remaining tissue is the final step and should again be labelled and submitted separately for pathological examination. Conclusions 1. Segregation of TUR material on an anatomical basis into 3 separate specimens is of considerable value to the histopathologist. It allows a more representative histological sampling of the prostate and a semiquantitative assessment of the extent of prostatic carcinoma. 2. I t offers the urologist a more precise characterisation of prostatic carcinoma which may help to select those for more extensive staging investigation and to choose treatment modalities.

Table I11

Table IV

Incidence of Prostatic Carcinoma found at Post-mortem Examination in 4 Reported Series.

Incidence of Unsuspected Prostatic Carcinoma after Prostatectomy

Moore (1935) Rich (1935) Kahler (1939) Emmett et al. (1962)

16.7 % 14.0% 17.3 % 24.0 %

Smith and Woodruff (1950) 9.0 % Bauer et al. (1959) 6.5 % Denton et at. (1965) 6.0% Step-section-t21~0% Varkarakis et al. (1970) 4.9 %

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Problems in T.U R. sampling

Benign prostatic hypertrophy

Peripheral zone

Fig. 3. Diagrammztic representation of changes within prostate with development of benign prostatic hyperplasia. Adolescent prostate

Effects of agcing I

Benign Drostatic

Peripheral zone

L

Central zone

1

Fig. 4. Method of sampling peripheral zone during TUR.

3. It has not led to an increased detection rate of unsuspected tumours in this pilot study.

4. Separation of a fourth specimen from the peripheral zone is desirable. Summary

The exclusion of prostatic carcinoma in TUR specimens represents a considerable problem for the histopathologist. A technique for the separation of tissue on an anatomical basis which has been carried out on 50 patients is piesented. It permits more representative histological sampling of TUR specimens and more accurate characterisation of prostatic carcinoma, but further refinement is recommended. References BARNES, R. W. (1943). Endoscopic Prosfatic Surgery. London: Kimpton. BARNES, R. W. and NINAN,C. A. (1972). Carcinoma of the prostate: biopsy and conservative treatment. Journal of Urology, 108, 897-900. BAUER.W. C., MCGAVIAN,M. H. and CARLM,M. R. (1960). Unsuspected carcinoma of the prostate in suprapubic prostatectomy specimens. Cancer, 13, 370-378. BLACKLOCK, N. J. (1974). Anatomical factors in prostatitis. British Journal of Urohgy, 46, 47-54. DENTON,S. E., CHOY,S. H. and VALK,W. L. (1965). Occult prostatic carcinoma diagnosed by the step-section technique of the surgical specimen. Journal of Urology, 93, 296-298.

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EMMETT,J. L., BARBER, K. W. and JACKMAN, R. J. (1962). Transrectal biopsy to detect prostatic carcinoma: a review and report of 203 cases. Journal of Urology, 87, 460-474. KAHLER, J. E. (1939). Carcinoma of the prostate gland: a pathological study. Journal of Urotogy, 41, 557-574. MCNEAL,J. E. (1969). Origin and development of carcinoma in the prostate. Cancer, 23, 24-34. MOORE,R. A. (1935). The morphology of small prostatic carcinoma. Journal of Urology, 33, 224-234. O’DONOGHUE, E. P. N., SHRIDHAR, P., SHERWOOD, T., WILLIAMS, J. P. and CHISHOLM, G. D. (1976). Lymphography and pelvic lymphadenectomy in carcinoma of the prostate. British Journal of Urology, 48, 689-696. RICH,A. R. (1935). On the frequency of occurrence of occult carcinoma of the prostate. Journal of Urology, 33, 21 5-223. SMITH, G. G. and WOODRUFF, L. M. (1950). The development of cancer of the prostate after sub-total prostatectomy. Journal of Urology, 63, 1077-1080. VARKARAKIS, M., CASTRO,J. E. and AZZOPARDI, J. G. (1970). Prognosis of Stage I carcinoma of the prostate. Proceedings of the Royal Society of Medicine, 63, 91-93.

The Authors E. P. N. O’Donoghue, FRCS, Senior Lecturer and Honorary Consultant, Institute of Urology, R. C. B.Pugh, MD, FRCPath, Consultant Pathologist, St Paul’s Hospital.

Early diagnosis of prostatic carcinoma: the role of transurethral resection.

British Journal of Urology (1977), 49, 705-710 0 Early Diagnosis of Prostatic Carcinoma: The Role of Transurethral Resection and R. C. B. PUGH Insti...
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