|Year : 2020 | Volume
| Issue : 16 | Page : 44-49
Pathologic findings in prostate gland at autopsy with topographic distribution of these diseases within the prostatic zones: Eleven-month prospective study in Oauthc, Ile-Ife, Nigeria
Ifeoma Florence Ezejiofor1, Williams Olufemi Odesanmi2, Oluwole Olaniyi Odujoko2, Akinwumi Oluagbenga Komolaefe2, Tosin O Alade2, Rinde O Olaofe2, Ibeh Charles Ibe2
1 Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria
2 Department of Morbid Anatomy And Forensic Medicine, Obafemi Awolowo University Teaching Hospitals Complex, Ile-ife, Osun State, Nigeria
|Date of Submission||08-Jun-2020|
|Date of Acceptance||11-Sep-2020|
|Date of Web Publication||26-Nov-2020|
Dr. Ifeoma Florence Ezejiofor
Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State
Source of Support: None, Conflict of Interest: None
Introduction: Different zones of prostate harbor different prostatic pathology. The peripheral zone shows majorly prostatic adenocarcinoma, which is among the common causes of cancer death in men in sub-Saharan Africa. Aim: The study aimed to determine the spectrum of prostate pathologies in routine autopsies of adult male 30 years and above whose death was unrelated to prostate diseases. Methods: A total of eighty cases of prostate glands were harvested over an 11-month period. These glands were fixed for 48 h, grossed, and processed. The hematoxylin- and eosin-stained slides were examined using multiheaded microscope. Results: The age range of patients was 30–85 years with a mean age of 41.84 ± 12.63 years standard deviation. The most common cause of death in these patients was trauma secondary to road traffic accident followed by cardiovascular diseases. The most common lesions in each prostatic zone as observed in this study were chronic prostatitis 26.3% in the central zone; nodular hyperplasia 16.3% in the transitional zone; prostatic atrophy (13.8%) and adenocarcinoma (8.3%) in the posterior peripheral zone (one of the cases (1.3%) showed multiple carcinomatous foci); and chronic prostatitis 15.0% in the anterior fibromuscular zone. Four patients' ages 30, 31, 32, and 48 years had Schistosoma haematobium infections observed in the seminal vesicles, whereas patient aged 48 years had in addition adenocarcinoma of prostate gland and prostatic atrophy (PA). A case (1.3%) of prostatic calculi and simple cyst of the prostate was seen in ages 56 and 85 years, respectively. Conclusion: Different zones of the prostate are associated with different disease entities, and S. haematobium show an association with adenocarcinoma of prostate in one individual
Keywords: Calcified ova of Schistosoma haematobium, male sex, prostatic adenocarcinoma, prostatic zones and lesions
|How to cite this article:|
Ezejiofor IF, Odesanmi WO, Odujoko OO, Komolaefe AO, Alade TO, Olaofe RO, Ibe IC. Pathologic findings in prostate gland at autopsy with topographic distribution of these diseases within the prostatic zones: Eleven-month prospective study in Oauthc, Ile-Ife, Nigeria. N Niger J Clin Res 2020;9:44-9
|How to cite this URL:|
Ezejiofor IF, Odesanmi WO, Odujoko OO, Komolaefe AO, Alade TO, Olaofe RO, Ibe IC. Pathologic findings in prostate gland at autopsy with topographic distribution of these diseases within the prostatic zones: Eleven-month prospective study in Oauthc, Ile-Ife, Nigeria. N Niger J Clin Res [serial online] 2020 [cited 2021 May 18];9:44-9. Available from: https://www.mdcan-uath.org/text.asp?2020/9/16/44/301638
| Introduction|| |
Prostate gland is divided into four zones, and each zone has a peculiar proliferative lesion significantly associated with it. Nodular hyperplasia of the prostate originates almost exclusively in the transition zone, whereas most carcinomas originate in the peripheral zone (PZ). Other pathologic lesions of the prostate glands include inflammation, atrophy, low-grade prostatic intraepithelial neoplasia (LGPIN), and high-grade intraepithelial neoplasia (HGPIN). The prostate gland is an important organ in the male gender, and because of growing literature on the disproportionate burden of prostate cancers among black men of West African descent, there is a need to study this seemingly small but significant organ of the male.,
Worldwide, prostate cancer is the second most frequently diagnosed cancer and the fifth leading cause of cancer death among men, with an estimated 1.1 million new cases diagnosed and 307,000 deaths in 2012, although in the USA, it stands as the most common cancers and the leading cause of cancer deaths., African American (Alameda) and Afro Caribbean (Jamaica) men have the highest incidence in the world, with approximately 160/100,000 and 314/100,000, respectively., Although prostate cancer incidence and mortality rates have been declining in both African American and White men since 1991, possibly due to improved diagnostic techniques, better screening, and improved surgical and radiologic treatments, the rates remain comparably higher among African American men. The mortality rate is also high in most of sub-Saharan Africa but low in North Africa and generally high in predominantly black populations; Caribbean, 26.3/100,000 and sub-Saharan Africa, 18–19/100,000. It is intermediate in Europe and Oceania but very low in Asia with incidence rate of 2.5/100,000 in Eastern Asia. In Nigeria, prostate cancer is still the most common cancer in males. It accounts for 11% in 1999 of all male cancers in the population served by the Ibadan Cancer Registry, and the incidence is increasing. Studies from Ibadan and from other sites in Nigeria (Benin, Calabar, Kano, Lagos, Maiduguri, and Zaria) also show an increasing incidence of prostate cancer, accounting for 6%–12% of total cancers in these centers and up to 18% in some. Current data in Nigeria show that, in both sexes, prostate cancer is the third most common cancer after breast and cervical cancer except in Port Harcourt, where a very high figure was recorded for prostate cancer as the most common cancer accounting for 34.7% of all cancers. The incidence rate in six geopolitical zones in Nigeria also showed that all zones have a high incidence rate of prostate cancers. The southwest (SW) and the northcentral have the highest rate in pre-PSA era and were surpassed by the South-South zone in PSA era with a dramatic deviation in annual incidence rate in the SW. This increase in the SW zone is probably due to the location of the cancer registries serving the tertiary university teaching hospitals at Ibadan and Ile-Ife.
| Materials and Methods|| |
A total of eighty prostate glands as calculated from the minimum sample size using a descriptive cross-sectional study were used. These glands were harvested over an 11-month period from routine autopsies in adult male 30 years and above in the Department of Morbid Anatomy and Forensic Medicine of the OAUTHC, Ile-Ife, Osun State. The criteria for the collection of these specimens were based on male participants whose death was unrelated to prostate diseases. The methodology used was partial sampling protocol according to the International Society of Urological Pathology (ISUP) on handling and staging of radical prostatectomy specimens 2012. In individual, the prostate glands were removed intact along with seminal vesicle and immediately divided partially in the midsagittal plane for optimal fixation in 10% formalin for 48 h. The gland was subsequently cleaned of any non-prostate tissue. The seminal vesicles were removed, and the prostate glands were weighed and measured in three dimensions (apical to basal = vertical, left to right = transverse, and anterior to posterior = sagittal). The glands were inked on the anterior surfaces by Red Indian ink manufactured by Tinta China Encre De Chine Acrylicos Vallejo and on the posterior surfaces by black Indian ink manufactured by West Design Folkestone CT19 4RJ England. These glands were immediately immersed into 5% Bouin's solution for proper fixing of the colors to their respective surfaces and subsequently separated into left and right lobes.
The specimens were sectioned according to the sampling protocol of ISUP. The apex and the base were cut horizontally first, while the remaining were subsequently cut and inserted in the sequentially six labeled cassettes. The specimens were placed, ensuring that well-inked PZs were shown in all cases. Finally, the seminal vesicles were sectioned, and as a minimum, the apex and a cross section were embedded in the seventh cassette. The cut sections were postfixed for an additional 24 h in 10% buffered formalin. They were dehydrated in graded alcohols, cleared in xylene, and embedded in paraffin. The paraffin blocks were cut into 4 μm sections by microtone and mounted on slides, which were subsequently stained with hematoxylin and eosin. These slides were viewed for the identification of any prostatic diseases. Data were analyzed using simple descriptive statistics – Chi-square test was used to measure associations with level of significance P = 0.05. Data were analyzed using statistics software (Statistical Package for the Social Sciences, SPSS Incorporated, version 21, Chicago, Illinois, USA).
| Results|| |
The populations of individuals involved in this study were all black Africans who lived in Ile-Ife, SW geopolitical zone of Nigeria and its environs.
The ages of the patients ranged from 30 to 85 years, with the mean age of 41.84 ± 12.63 years standard deviation (SD). The peak age incidence of death was 30–39 years with a frequency of 43 (53.75%) followed by 40–49 years with a frequency of 15.5 (19.37%), while the least is from 70 years and above [Figure 1].
|Figure 1: Histogram displaying frequencies of death within different age groups with highest death frequencies shown within age group 30–40 years|
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Distribution of prostate weights with age group
The weights of the prostate glands ranged from 18 to 64 g with a mean weight of 27.9 ± 9.8 g SD. There was a significant increase in the mean weight of prostate gland with increasing age but with a slight decrease in the age group 70–79 years. The heaviest prostate gland was, however, recorded in the age group 80–89 with weight of 64 g. There is a significant correlation coefficient of age versus weight, 0.803 (P = 0.0001). This shows that weight of the prostate gland increases with age [Figure 2].
|Figure 2: Histogram showing the increasing mean weight of prostate glands with increasing age groups with the highest weight (64 kg) seen within 80–89 years|
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Frequencies of prostate pathologies in different zones of prostate glands
The most common lesion identified in the transitional zone (TZ) was nodular hyperplasia (NH) [Figure 3]a with a frequency of 13 (16.3%) followed by chronic prostatitis accounting for 8 (10.0%) [Figure 3]b. Most cases of NH occurred in a higher age group (50 years and above) except one case of NH, which was seen in a 30-year-old male who died from hemorrhagic shock secondary to gunshot injuries.
|Figure 3: (a) Photomicrograph showing nodular hyperplasia in a 30-year-old male who died from hemorrhagic shock secondary to gunshot injuries (H and E, ×40). (b) Frequencies of prostate pathologies in transitional zone showing nodular hyperplasia (b) as the most common lesion|
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The majority of the central zone (CZ) appears unremarkable, with only one case of simple cyst [Figure 4]a. The most common lesion identified in this zone was chronic prostatitis, with a frequency of 21 (26.3%) [Figure 4]b.
|Figure 4: (a) Photomicrograph showing a simple cyst in an 85-year-old male who died from intracranial hemorrhagic secondary to hypertensive heart disease (H and E, ×100). (b) Frequencies of prostate pathologies in the central zone showing chronic prostatitis as the most common lesion|
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The most common lesion identified in PZ was PA, with a frequency of 11 (13.8%). This is followed by adenocarcinoma with Gleason's Grade 2, score 4 and Gleason's Grade 3, score 6 [Figure 5]a. The adenocarcinoma altogether had a frequency of 7 (8.9%). One of the cases showed multiple carcinomatous foci within the PZs. Three of these seven cases of adenocarcinomas had a precursor lesion of high-grade intraepithelial lesion CHP) [Figure 5]b, while one had a concomitant lesion of schistosomiasis in its seminal vesicle [Figure 6]. The least represented was prostatic calculi, with a frequency of 1 (1.3%).
|Figure 5: (a) Frequencies of prostate pathologies in peripheral zone showing adenocarcinoma and atrophy (a) as the most common lesions. (b) Photomicrograph showing adenocarcinoma Gleason's Grade 2, score 4 in a prostate of a 60-year-old male with high-grade prostatic intraepithelial neoplastic (arrowhead) who died from multiple injuries secondary to road traffic accident (H and E, ×100)|
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|Figure 6: Photomicrograph showing calcified ova of Schistosoma haematobium in the wall of the seminal vesicle of 48-year-old male with concomitant adenocarcinoma of the prostate gland who died from overwhelming sepsis (H and E, ×100) (arrowheads point to the terminal spine of Schistosoma haematobium)|
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The only lesion identified in the anterior zone (AZ) was chronic prostatitis, with a frequency of 12 (15.0%) [Figure 7].
|Figure 7: Frequencies of prostate pathologies in the anterior zone showing chronic prostatitis as the major lesion with the large area being disease free (n)|
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The only lesion identified in seminal vesicle was calcified ova of Schistosomahaematobium [Figure 6] in the walls of the vesicles with a frequency of 4 (5%).
| Discussion|| |
Distinct morphological zones exhibit a zone-specific susceptibility of prostate diseases. Many researchers relate these susceptibilities to distinct gene expression profiles in different zones, which may contribute to these diverse behaviors. The recent comprehensive research analysis of 500 prostate glands conducted by Mc Neal revealed that prostatic adenocarcinoma develops mainly in the PZ, whereas NH occurs almost exclusively in the TZ while CZ remains mostly disease free. These findings concur with the present study where the majority of pathology at the PZ are adenocarcinoma coexisting with either atrophy, NH, HGPIN, or chronic prostatitis, while 89% of CN remains unremarkable. Thiel and Effert also recorded that prostate cancer developed infrequently in the CZ compared to PZ and rarely arises from the seminal vesicle and attributed this to the fact that CZ and seminal vesicle arise from Wolffian ducts, while the rest of prostate arises from urogenital sinus. The only outstanding lesion in the seminal vesicle of the present study was four cases of calcified ova of S.haematobium. Jackson et al., who also worked on characterization of prostate carcinoma among blacks, revealed that the tumor in African descendants tends to present at a younger age and is more advanced and histologically have a poorer prognosis as well as numerous carcinomatous foci. Moreover, Sánchez-Chapado et al. reported on the prevalence of prostate cancer and PIN on 162 Caucasian Mediterranean (CM) men who died secondary to trauma and revealed 77.7% of prostate cancer and HGPIN in the PZ and that the incidence starts at ages 30 years and above and is more in Caucasian American and Afro-American but lower in CM. Further studies on the frequency of latent prostate cancer by Zare-Mirzaie et al. on 149 Iranian autopsy specimen revealed LGPIN in 34 (22.8%), HGPIN in 26 (17.4%), and invasive adenocarcinoma in 14 (9.4%). Most of the tumors were located in the posterior lobe of prostate and were more frequent in older men (>65 years of age) and heavier prostates. All invasive adenocarcinomas were accompanied by PIN. Similarly, seven cases of incidental adenocarcinomas in this index case were also seen in the posterior PZ with concomitant HGPIN in three cases and calcified ova of S.haematobium of seminal vesicle in four cases aged 30, 31, 32, and 48 years with deceased 48 years having concomitant adenocarcinoma. Only one case (1.3%) of adenocarcinoma showed multiple carcinomatous foci similar to Jackson's work. However, a study done by Okani et al. in Ibadan, Nigeria, recorded the absence of PIN in all cases of incidental adenocarcinoma in his center.
Zonal differences in nodular hyperplasia (benign nodular hyperplasia)
Mc Neal and other researches in the literatures reported that NH is almost exclusively in the TZ. Tang et al. and several other studies also reported that NH is present in the outer zone of the gland in up to 18.5% of prostate specimens and that some hypoechoic nodules in the PZ visualized on ultrasound could be histologically demonstrated as NH. The present study also revealed highest frequency (16.3%) of NH in the TZ with just 5.2% in the PZ and less than 1.3% in the AZ and CZ. Most of the cases were seen in males 50 years and above except one case in a 30-year-old male who died from hemorrhagic shock secondary to gunshot injuries similar to work reported by Okani et al.
Prostatic adenocarcinoma and schistosomiasis
Several studies in literatures and case reports (Tanzania, Canada, Brazil, and Nigeria) had reported concomitant prostatic adenocarcinoma with S. haematobium infection and one with Schistosoma mansoni of prostate gland or seminal vesicle. Out of four cases of calcified ova of S. haematobium infections, only one aged 48 years had adenocarcinoma.
The pathogenesis of PA includes compression of hyperplastic nodules, inflammation, hormone or nutritional deficiency, and systemic or local ischemia. This lesion is a frequent mimic of prostatic adenocarcinoma, but there is no relationship of this lesion to latent carcinoma or HGPIN. Billis who worked on 100 consecutive autopsies of men more than 40 years of age revealed that 85 cases of PA occurred almost exclusively in the PZ of the gland and gained importance with increasing age. A similar work by Okani et al. in Ibadan revealed that all PA (24.1%) are associated with increasing age with peak incidence at the seventh decade of life with continued progression of the process into the eighth decade. In the index case, all 11 cases of PA were identified in the PZs of the gland, with a frequency of 13.8%. Most were seen in the higher age groups.
This study revealed that chronic prostatitis was the most common lesion encountered with a total frequency of 47 (57.8%). This is similar to the prospective study conducted by Ghartimagar et al. in India over 100 consecutive autopsy cases, which revealed 62 cases of chronic inflammation and two cases of acute inflammation. Aslam et al. in Karachi in Pakistan revealed a similar pattern of lesions and stated that the most frequently encountered diseases affecting prostate are prostatitis, benign prostatic hyperplasia, and prostatic cancer.
Prostatic cyst index study also documented a case of simple cyst in the CZ with and atrophy at in the PZ of an 85-year-old male. Galosi et al. and Nghiem et al. reviewed ultrasound cystic prostatic lesions and classified these lesions into six categories, isolated medial cyst, cyst of the ejaculatory duct, simple or multiple cysts of the parenchyma, complicated infections or hemorrhagic cyst, and cysts secondary to parasitic diseases., Several researches also reviewed that cysts of the prostate were also related to atrophy of the prostate (as seen in the index case), inflammatory disease, benign prostatic hyperplasia, ejaculatory duct obstruction, and cancer.,
This study also revealed one interesting case of prostatic calculi in the PZ in a 56-years-old male. Ghartimagar et al. also reported a case of calcification in a 65-year-old patient. Sondergaad et al. performed 300 consecutive autopsies and found calculi in 99% of the prostate glands with a major location in the ducts of the border zone between the middle lobes and the peripheral prostate posterolaterally. Several studies have implicated that true prostatic calculi are formed by the deposition of calcareous material on corpora amylacea, which convert them into calculi while some believe that corporal amylacea serve only as nuclei and infection also contribute to the formation of some prostatic calculi.
| Conclusion|| |
Different lesions of prostate are zone sensitive with central and anterior zones practically free of lesions in 72.5%–85% of cases, respectively, while PZ harbors PA and carcinoma. Prostatic adenocarcinomas still have low frequency in our environment, but the association of this cancer with HGPIN and schistosoma infections has been observed in this study.
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Conflicts of interest
There are no conflicts of interest.
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