|Year : 2022 | Volume
| Issue : 2 | Page : 78-82
Audit of prostatic diseases diagnosed from Tru-Cut biopsies in Nnamdi Azikiwe University Teaching Hospital, Nnewi, using the P63 immunohistochemical marker
Kingsley C Madubuike1, Chinedu Onwuka Ndukwe1, Michael Emeka Chiemeka1, Ifeoma Florence Ezejiofor1, Christian C Ogbu1, Igwebuike Victor Onyiaorah1, Simeon Onyechere Nwosu2
1 Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria
2 Department of Anatomic Pathology, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria
|Date of Submission||09-Nov-2021|
|Date of Acceptance||04-Dec-2021|
|Date of Web Publication||04-Jul-2022|
Chinedu Onwuka Ndukwe
Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi
Source of Support: None, Conflict of Interest: None
Background: There is growing literature on the burden of prostatic lesions: both benign and malignant among men of West African ancestry. There are also some studies on the prostate in Anambra State and South-East Nigeria, but these are mainly on patterns and prevalence, without the use of immunohistochemistry. Aims and Objectives: The aim of this study is to determine the histological pattern of prostatic diseases diagnosed from Tru-Cut biopsies in Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, South-East Nigeria, using the p63 immunohistochemical marker. This will be a pioneer study in both the state and the geopolitical zone. Materials and Methods: This is a 2-year (January 2019 to December 2020) retrospective study of the immunohistochemical expression of p63 on the haematoxylin and eosin-diagnosed Tru-Cut biopsies of the prostate in the archives of the histopathology laboratory in NAUTH, Nnewi. A Purposive sampling method was used with a sample size of 151. Sections were made from the blocks, reviewed and stained using the p63 immunohistochemical marker. Results: There were 191 cases of prostate diseases histologically diagnosed, of which 151 met the inclusion criteria for the study. Of the 151 cases, 97 (64.2%) were diagnosed as benign and 54 (35.8%) were diagnosed as malignant. Following p63 immunohistochemistry, 97 cases were accurately diagnosed as benign and 54 cases accurately diagnosed as malignant with no misdiagnoses. The age of the patients ranged from 50 years to 90 years; however, the predominant population was in the sixth decade (31.8%) and seventh decade (35.1%), with a mean age of 75.3 years. There is no significant difference noted in the mean age of the non-neoplastic and neoplastic groups. Conclusion: This study shows that morphology alone is sufficient for the diagnosis of both Benign and prostatic lesions, as shown by the accuracy level (100%) in the haematoxylin and Eosin results. This is particularly important in resource-poor settings such as ours.
Keywords: Histopathology, immunohistochemistry, Nigeria, p63, prostatic lesions
|How to cite this article:|
Madubuike KC, Ndukwe CO, Chiemeka ME, Ezejiofor IF, Ogbu CC, Onyiaorah IV, Nwosu SO. Audit of prostatic diseases diagnosed from Tru-Cut biopsies in Nnamdi Azikiwe University Teaching Hospital, Nnewi, using the P63 immunohistochemical marker. Hamdan Med J 2022;15:78-82
|How to cite this URL:|
Madubuike KC, Ndukwe CO, Chiemeka ME, Ezejiofor IF, Ogbu CC, Onyiaorah IV, Nwosu SO. Audit of prostatic diseases diagnosed from Tru-Cut biopsies in Nnamdi Azikiwe University Teaching Hospital, Nnewi, using the P63 immunohistochemical marker. Hamdan Med J [serial online] 2022 [cited 2022 Aug 8];15:78-82. Available from: http://www.hamdanjournal.org/text.asp?2022/15/2/78/344194
| Introduction|| |
The prostate gland is an important organ in male gender. There is growing literature on the burden of prostatic lesions: both benign and malignant among black men of West African ancestry; therefore, there is a need to study this seemingly small but significant organ of the male gender.
Diseases of the prostate gland constitute a significant source of morbidity and mortality among male adults worldwide. Within the last two decades, there has been a sudden increase of interest in the diseases of the prostate, largely due to the perceived high incidence of prostate cancer in different geographical and ethnic groupings globally. Of all the diseases that affect the prostate, the most frequently encountered in clinical practice are nodular hyperplasia (NH), prostate cancer and prostatitis. There are some mimickers of prostate adenocarcinoma, especially in thin core needle biopsy, and they include atrophy, post-atrophic hyperplasia, atypical adenomatous hyperplasia and seminal vesicle-type tissue, Cowper's gland and others. NH is the most common urologic disorder in men beyond 40 years of age. It is a pathologic process that contributes to but is not the sole cause of lower urinary tract symptoms in ageing men. The clinical incidence of this disease is only 8% during the fourth decade, but it reaches 50% in the fifth decade and 75% in the eighth decade.
Prostate cancer is the fourth most common cancer in men worldwide. It is predominantly a disease of elderly men, with more than 75% of new cases being diagnosed in persons older than 65 years. It is usually preceded by a spectrum of histopathological changes within the acini, referred to as high-grade prostatic intraepithelial neoplasia (HGPIN). Histologically, most prostate cancers are acinar adenocarcinomas, while non-acinar carcinomas and sarcomas are relatively rare. Of the various grading systems of acinar adenocarcinoma, the Gleason grading system has received the most widespread acceptance. Most patients, especially in Nigeria, with prostate cancer present late in the advanced stages of the disease and with a high Gleason's score.
Prostatitis is a common debilitating urologic disease that is characterised by inflammation of the prostate gland. The National Institute of Health classification of prostatitis has four categories, designated as I, II, III and IV, representing acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis or chronic pelvic pain syndrome (inflammatory and non-inflammatory) and asymptomatic inflammatory prostatitis, respectively. In the United States, prostatitis is diagnosed in 8% of all urologist visits and 1% of all primary care physician visits.
The role of a pathologist in assessing them has assumed much importance with the advent of the needle biopsy. The only test that can fully confirm the diagnosis of prostate cancer is a biopsy. The histological diagnosis is based on the morphological patterns seen and using the Gleason grade system. The current study by the International Society of Urological Pathology (ISUP) has shown that what was formerly referred to as patterns one and two in the Gleason scoring system are in fact, benign and not malignant as proposed by Gleason.
Immunohistochemistry is an ancillary technique that is helpful in making a definitive diagnosis. p63 and 34betaE12 are useful in the diagnosis of prostate cancer, though p63 has greater sensitivity and specificity and so can be used to separate between benign and malignant prostatic lesions. Other prostate tissue markers include basal cell markers (high molecular weight cytokeratin, cytokeratin 5/6 and p63), alpha-methylacyl-CoA racemase, Ets-related gene product, fatty acid synthase and Golgi phosphoprotein 2 (GOLPH 2).
This study aims to determine the histological pattern of prostatic diseases diagnosed from Tru-Cut biopsies in Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, South-East Nigeria, using the p63 immunohistochemical marker.
| Materials and Methods|| |
The histopathology laboratory of NAUTH, Nnewi, was used for this study. NAUTH was established as a teaching hospital in 1990 with five annexes and its main centre is located at Nnewi, one of the big commercial centres in Anambra State. As the major tertiary hospital in the state, it serves as a referral centre and provides a wide range of medical and outpatient services to the state and other neighbouring states. The hospital has a total bed capacity of about 440.
This was a retrospective study of the immunohistochemical expression of p63 on the haematoxylin and eosin (H and E)-diagnosed Tru-Cut biopsies of the prostate in the archives of the histopathology laboratory in NAUTH, Nnewi, South-East Nigeria, over a 2-year period (January 2019 and December 2020).
The tissue blocks of all the Tru-Cut specimens diagnosed histologically as prostate disease using H and E only in the aforementioned facility over a 2-year period, between January 2019 and 31 December 2020, were used for this study.
Sample size determination
This was determined from all the Tru-Cut biopsies of the prostate diagnosed in the histopathology laboratory NAUTH, Nnewi, which was 151 in number.
Purposive sampling method was used.
All Tru-Cut biopsies of prostatic diseases diagnosed during the study period having adequate data and tissue blocks available were included in the study.
Tissue blocks with inadequate tissue left for sectioning, cases with missing tissue blocks and cases with inadequate or missing data were excluded from the study.
The formalin-fixed and paraffin-embedded (FFPE) tissue blocks of all histologically diagnosed (using H and E only) from Tru-Cut biopsies of the prostate that met the inclusion criteria were selected for this study.
The FFPE tissue blocks of all cases of prostate diseases diagnosed in the study period were retrieved from the archives. Fresh sections were cut and stained with haematoxylin and eosin and were re-examined histologically.
All prostatic diseases were stained for p63 antigens through the indirect biotin-streptavidin method. There was sectioning of 5 μm tissue from tissue blocks and these were placed on charged slides. The sections were deparaffinized in xylene and rehydrated in graded alcohol. All slides stained for p63 were microwaved for 15 min in 10 mmol/L citrate buffer, pH 6.0 (BioGenex, San Ramon, CA) in a 750-W oven. The slides were allowed to cool at room temperature for 30 min. The 4A4 anti-p63 antibody which recognises all six p63 isotypes was applied (1:50 dilution) at room temperature for 2 h in an automated stainer (Optimax plus 2.0 basal cell; BioGenex, San Ramon, CA). Detection steps were performed using the automated stainer with the MultiLink-HRP kit (BioGenex). Peroxidase activity was localised using 3, 3diaminobenzidine-nickel chloride.
Ethical approval for the study has been obtained from the Ethics Committee of NAUTH, Nnewi, with a reference number; NAUTH/CS/66/VOL. 10/35/2017/031. Relevant data which include nature of specimen and histological diagnoses were extracted from the request forms and histology reports.
Interpretation of result
The antibody p63 is a basal cell marker which stains basal cell nuclei. p63 stain is present in benign prostatic diseases because they still contain basal cells, while p63 is absent in cases of prostate cancer as the malignant prostate glands lack basal cells. A specimen was considered to be positive when it stains the basal cells only without staining any other cell in the prostate as seen in benign lesions of the prostate, a specimen was considered to be negative when no basal cell is stained and no other cells of the prostate stained as seen in prostate cancer.
The data analysis was done using the SPSS Statistics for Windows, Version 20.0. (IBM Corp. Armonk, NY, USA) and the results were presented in tables and charts.
Limitations of the study
Cases without adequate data such as age, marital status, PSA value and type of biopsy made data analysis problematic. In addition, poor tissue processing and preservation made antigen retrieval difficult in some cases.
| Results|| |
A total of 191 prostatic core needle biopsies were received in NAUTH, Nnewi, for the 2-year period under review (2019–2020). Of these, 116 were histologically diagnosed as benign; 34 of these were benign without inflammation, while 81 were benign with inflammation and only one showed just inflammation without any other lesion. Sixty-two cases were histologically diagnosed as adenocarcinoma of varying Gleason's grade and 13 cases were inadequate for histological evaluation.
Forty cases were excluded from the study for various reasons which included inadequate data on the request forms, missing tissue blocks and poorly preserved tissue blocks. Hence, 151 cases were eventually enlisted into this study. However, since this is an audit, the 151 cases were subjected to p63 immunostain to confirm or disprove the histologically made diagnoses.
The various histological patterns of the haematoxylin and eosin-diagnosed prostate biopsies
The histologically diagnosed prostate biopsies show that, of the 151 cases, 41.1% (62/151) of them were benign with chronic inflammation, 22.5% (34/151) were benign without chronic inflammation, 0.7% (1/151) was HGPIN and 35.8% (54/151) were diagnosed as malignant. Seven (7.2%) of the benign cases have foci of basal cell hyperplasia and 4 (4.1%) have foci of squamous metaplasia. In the malignant cases which were all adenocarcinoma, ISUP/WHO grade group 5 was more commonly encountered (36.7%), followed by grade group 4 accounting for 26.7% and grade group 1 accounting for 16.7% of the cases. Grade groups 2 and 3 accounted for 10.0% each. Fifteen cases (27.7%) showed foci of perineural invasion.
Determination of the presence of p63 in the haematoxylin and eosin-diagnosed prostate biopsies
Following immunostaining for p63, the 62 cases diagnosed with benign with chronic inflammation and 34 cases diagnosed with benign only were found to be truly benign as shown by diffuse positivity to p63. The only case diagnosed as HGPIN was also found to be accurate as shown by patchy positivity to p63. All the 54 cases diagnosed as malignant were truly malignant as shown by the absence of any positive spot to p63 in the tumour [Figure 1], [Figure 2], [Figure 3], [Figure 4].
|Figure 1: Showing benign prostate lesion with chronic inflammation (H and E, ×100)|
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|Figure 2: Diffuse positivity of p63 highlighting the basal cells of the prostate glands and corpora amylacea (×400)|
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|Figure 3: Adenocarcinoma of the prostate arranged in cribriform and sheets (H and E, ×200)|
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|Figure 4: Prostate adenocarcinoma with glands lacking basal cells as evidence by negative p63 staining (×200)|
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The age range of the confirmed benign prostatic lesions is 50–90 years with a mean, median and modal age of 74, 80 and 80 years, respectively, with a standard deviation of 1.0216 [Figure 5].
|Figure 5: Bar chart showing age range distribution of the malignant and benign lesions|
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The age range of the cases confirmed to be malignant is 50–90 years with a mean, median and modal age of 76, 80 and 70, respectively, with a standard deviation of 0.9548 [Figure 5].
| Discussion|| |
Prostatic specimens constitute a good percentage of the workload in the pathology laboratory. This study was mainly to audit the various histological lesions in prostate biopsies.
In this study, the age of the patients ranged from 50 years to 90 years; however, the predominant population was in the sixth decade with 48 cases (31.8%) and the seventh decade with 53 cases (35.1%) and having a mean age of 75.3 years. There is no significant difference noted in the mean age of the non-neoplastic and neoplastic groups. This result is similar and agrees with the studies done locally by Obiora et al., Anunobi et al., Mohammed et al., Nwofor et al. and internationally by Garg et al., Deshmukh et al. In this study, of 151 cases, 97 (64.2%) were non-neoplastic lesions, whereas neoplastic lesions constituted 54 of the total cases (35.8%). This agrees with so many studies that show non-neoplastic lesions forming the bulk of the lesions such as those done locally by Anjorin et al., and internationally by Mittal et al. and George et al. The incidence of the neoplastic lesion is comparable with the study done by Obiorah CC and Nwosu on neoplastic lesions only.
In this study, the non-neoplastic lesions with NH without chronic inflammation were a total of 34 cases (22.5%); however, a similar study done by Gupta et al. showed 63.64%, Anjorin et al. 60.4% and George et al. About 88.5% of the cases they studied were benign without chronic inflammation, the reason for this difference is not known.
Benign with chronic inflammation formed the predominant subgroup of the non-neoplastic lesions with 62 (41.1%) cases; Mittal et al. got 38.39% and Gupta et al. recorded 32.69% which are relatively close. However, the study by Anjorin et al. got 11.2% of benign with chronic inflammation. Among the 96 cases of benign, 7 of the cases (7.2%) showed basal cell hyperplasia and 4 of the cases (4.1%) showed squamous metaplasia. Studies by Mittal et al. showed that basal cell hyperplasia and squamous metaplasia accounted for 5.4% and 3.24%, respectively, which is closely related to the findings in our study. However, Gupta et al. recorded 3.85% and 0.82% for basal cell hyperplasia and squamous metaplasia, respectively, which is comparable to our findings. It is very important to recognise the presence of basal cell hyperplasia and squamous metaplasia, as these are also mimics of adenocarcinoma.
Out of the 151 cases studied, only 1 case (0.7%) showed high-grade prostate intraepithelial neoplasia; studies by George et al. and Gupta et al. recorded 0.6% and 0.55%, respectively, as high-grade prostate intraepithelial neoplasia and this is very similar to my result.
The prevalence of prostate adenocarcinoma in this study was 35.8%, i.e., 54 of the 151 cases; Obiora and Nwosu reported 37.4%, which is similar to this study. However, Mohammed et al. reported 24.6%, Forae and Aligbe published 23.6% and Gupta et al. 20.05%, which are comparable to this study.
Most cases of prostate cancer are diagnosed after 50 years of age, but prostate cancer can be seen in younger adults. The frequency increases with age. In this study, the age range was wide (50–95 years) with a mean age of 72.2 years. However, the majority of the cases were seen in the age group 71–80 years and closely followed by the age group 61–70 years.
Histological grade has been recognised as a powerful prognostic factor of prostate cancer, and high-grade prostate adenocarcinoma, Gleason grade groups 4 and 5 (GS 8,9 and 10) were the most common grade recorded in this study (63.4%) which are in consonance with results from Anjorin et al., Obiora and Nwosu and Gupta et al.
Perineural invasion is regarded as pathognomonic of prostate cancer if there is circumferential or intraneural invasion by the tumour cells. Out of the 54 cases of adenocarcinoma, 15 cases (27.7%) showed perineural invasion. This is similar to the findings of Bastacky et al. (20%) though Gupta et al. (42.5%) reported a higher value.
Immunohistochemistry was done on the 151 cases of prostate diseases; 97 cases that were diagnosed histologically as benign showed positivity for the p63 marker (100%). Out of these 97 cases, 96 were diagnosed histologically as benign and they showed diffuse circumferential nuclear staining to p63, whereas one case diagnosed histologically as HGPIN showed patchy nuclear staining to p63 marker. The 54 cases diagnosed histologically as malignant showed complete negativity to p63 markers (100%). Studies by Baig et al. and Paner et al. showed that cases of prostate adenocarcinomas were all negative for p63 stain and all benign prostatic lesions positive for p63 stain. This correlates with the findings in this study.
| Conclusion|| |
This study shows that morphology alone is adequate for the diagnosis of both benign and malignant prostatic lesions as shown with the accuracy level (100%) in the haematoxylin and eosin results. This is particularly important in resource-poor settings such as ours.
Ethical approval for the study has been obtained from the Ethics Committee of NAUTH, Nnewi, with a reference number; NAUTH/CS/66/VOL.10/35/2017/031.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]