A total of 225 cases were reviewed comprising of patients who presented with infertility and had either azoospermia or oligospermia diagnosed on routine seminal fluid analysis.

Their ages ranged from 20 years to 60 years with a mean age of 37.7 years (SD = 8.61). The highest proportion of the cases, 31.6%, was found among the age group 30-39 years. The majority, (82.7%), had primary infertility while 17.3% had secondary infertility.

Seminal fluid analysis reports had shown that most of the cases reviewed had azoospermia, (92.9%), while others had oligospermia. Only 9.8% had clinical evidence of obstruction. Azoospermia was seen in 93% of the primary and 92.5% of the secondary infertility cases.

All the cases were histologically classified into six categories (figure 1).

Hypospermatogenesis (Hypo) was the most common pattern seen comprising 34.2%, followed by peritubular hyalinization/ tubular fibrosis (PHTF) in 32%, maturation arrest (MA) in 14.2%, Sertoli cell-only syndrome (SCOS) in 6.7%, while the least pattern were cases of normal histologic pattern in 0.9%. The photomicrographs of each pattern are shown in figure 2 below. Twenty-seven cases (12%) had a mixed histological pattern where more than one morphologic picture was seen in the same biopsy (Figure 3).

In relating the different histologic patterns with the types of infertility, more cases of primary infertility were seen in all the different histologic patterns compared with secondary infertility. Peritubular hyalinization/tubular fibrosis is the commonest pattern seen among cases of primary infertility (87.5%) while Hypospermatogenesis is the commonest in the secondary type (43.6%). The two histologically normal cases also had primary infertility (100%). Clinical evidence of obstruction was seen to be more associated with hypo spermatogenesis, (40.9%) and maturation arrest, (31.8%) (Table 1).

In this study, the mixed histologic pattern constituted 12% of the entire cases reviewed (Table 2) with various combinations which include peritubular hyalinization/tubular fibrosis with hypo spermatogenesis and peritubular hyalinization/tubular fibrosis with maturation arrest in 29.6% each, peritubular hyalinization/tubular fibrosis with Sertoli cell-only syndrome in 18.6%, both hypo spermatogenesis with Sertoli cell-only syndrome and maturation arrest with Sertoli cell-only syndrome in 11.1% of cases each.

Most of the mixed histologic pattern cases, 77.8%, had primary infertility. Table 3 showed the association between the mixed histologic patterns, semen analysis report and evidence of obstruction. However, these relationships are not statistically significant (p ≥ 0.05)

We reviewed testicular biopsy specimens from 225 men diagnosed by seminal fluid analysis to be either azoospermic or oligospermic. The mean age of the cases was 37.7 years (SD 8.61, range 20-60 years1112

Primary infertility was commoner than secondary infertility in this study, as was the pattern seen in a few previous studies elsewhere in Nigeria.1314 reported 49.2% of patients with primary infertility and 22.2% with secondary infertility in Ilorin. Couples with primary infertility tend to present early for fertility evaluation in the health centre due to socio-cultural factors and family pressures than those with secondary infertility who had once had a pregnancy to term irrespective of the outcome or those with one or more children in this environment13.

As shown, the majority of cases were in the age range 30-39 years corresponding to the peak of male reproductive activity and the age of psychological maturity when infertile men are most concerned about their condition and seek medical attention15.

In this study, 209 (92.9%) patients were azoospermic by the SFA report while others were oligospermic. Also, the clinical history of obstruction and clinical evidence of obstruction was noted in 10% of cases with azoospermia while none of the oligospermic patients had any associated clinical obstruction. This finding is similar to what was reported in some of the previous local and international studies.1617 The evaluation of the possible aetiopathogenesis of testicular damage in non-obstructive azoospermia, which has a high incidence in this environment may help in the prevention and management of male infertility.

Normal spermatogenesis has been seen in a variable proportion of testicular biopsies done in the investigation of primary infertility. These usually represent post-testicular problems in such patients (including obstruction). In many studies, these were reported in up to between 33% and 50% of cases. 181920 The frequency of normal spermatogenesis in the present study is much lower at 0.9%.

Hypospermatogenesis (Hypo) was the most common pattern seen in this study constituting 34.2% of the cases. A similar pattern but with a higher proportion was seen in the study by Obafunwa et al. from Lagos 5, Ahmed et al from Zaria11 and Nagpal et al. from India21 while a lower prevalence was seen in other previous studies done in this environment including the previous study from this centre by Thomas18 who reported 19% of cases. Ikuerowo et al22 from Lagos, Ojo et al14 from Ilorin and Oranusi et al23 from Nnewi reported 3.9%, 4.8% and 10% of cases with Hypospermatogenesis respectively. Various reasons were adduced for the sharp differences in the percentages by some of these authors, which are also similar to the reasons identified among the few that are specified in this study too, which include exposure to noxious chemicals (lead, various toxic industrial fumes especially gasoline vapour), drugs e.g. Nifedipine, Moduretic and physical agents (especially heat, tightly fitted underwear which apposes the testes closely to the body).3513

Maturation arrest (MA) was observed in 32 (14.2%) cases with an arrest at different levels of maturation, none reaching up to the level of spermatid. Those reviewed in this study were at the level of spermatogonia and primary spermatocytes. The incidence of maturation arrest was similarly lower in the previous study from Ibadan where 5.3% was reported. Philip et al12 reported 5.9% and a very low incidence of 0.4% was reported by Ali from Saudi.24 However, a higher relative proportion of 27.5% and 25.4% were reported by Ikuerowo et al22and Ojo et al. from Lagos and Ilorin respectively.14.

Sertoli cell-only syndrome (SCOS) was found in 6.7% of cases. This pattern usually has a very low incidence and was so documented by Thomas18 in Ibadan who reported 9.2% and by Obafunwa et al5 and Phillip et al12 who documented 1.1% and 1.5% respectively. In contrast, some of the studies reported higher incidences. Ahmed et al11 from Zaria reported 28.2% of cases, Rasheed et al.4 from Egypt reported 34% of cases. In India, Mehrotra et al19 and Nagpal et al21 reported 29.3% and 17% respectively.

Peritubular hyalinization/tubular fibrosis (PHTF) was found in 32% of the cases in this study. This was less frequent than in the previous study done by Thomas with 23% cases.18. Two recent studies from Lagos by Ikuerowo et al22 and Ojo et al14 similarly reported high incidences of 58.8% and 55.6% while some other studies reported low incidences such as those of Ahmed et al11 from Zaria (6.1%) and Rasheed et al4 from Egypt (6.0%). Al-Rayess et al16 and Ali et al24 from Saudi reported 12% and 19% respectively.

A mixed morphological pattern was diagnosed in this study when over 30% of either pattern was present and this was the case in 28 (12%) patients. Of these, there were 9 cases of peritubular hyalinization/tubular fibrosis admixed with hypo spermatogenesis; 8 cases of peritubular hyalinization/tubular fibrosis mixed with Maturation arrest; 5 cases of peritubular hyalinization/tubular fibrosis mixed with Sertoli cell-only syndrome; 3 cases of Sertoli cell-only syndrome mixed with hypo spermatogenesis and 3 cases of Sertoli cell-only syndrome mixed with maturation arrest.

The limitation of this study includes the smaller number of samples over a long period, absence of fertility hormone profile and lack of molecular or genetic testing capability of the institution to further screen the participants for genetic anomalies for a better correlation with morphologic patterns seen.

Some studies identified different discordant patterns in right and left testes, supporting the use of bilateral testicular biopsies for a more comprehensive evaluation of male infertility. Although the absence of spermatozoa in one testis in such cases does not rule out their presence in the other2 a unilateral biopsy has been seen to suffice in revealing the pathology in most instances225. A bilateral biopsy seems needful only when there is a significant difference in the size of the testes and especially when considering sperm retrieval for an intracytoplasmic sperm injection (ICSI) in the management of infertile couples with male infertility262728 .

From the literature, there is significant geographical variation in the histological patterns in male infertility as shown in Table 4

The high prevalence of normal spermatogenesis in a previous study was attributed to the high incidence of chronic inflammation resulting in fibrosis of the excurrent ducts. This seems to occur with much lower frequency in recent studies due to the advent of indiscriminate antibiotic use in our environment which has reduced the incidence of chronic inflammatory patterns seen in these patients.521 Besides, Klinefelter syndrome is reported less frequently in recent studies due to improved methods for early diagnosis including in-utero diagnosis negating the need for testicular biopsy in the evaluation of such patients for infertility.51821. In another study, 2.7% had chromosomal abnormalities, of which less than half had sex chromosome abnormalities (mainly 47, XXY) while Y-chromosome microdeletions were detected in 5.4%.29

The variations observed between this study and some other previous studies are not well understood. However, previous local and international studies have suggested increasingly, the importance of occupation, environmental, sociocultural habits, consanguineous marriages, and in particular, genetic factors in the cause of male infertility303132.

Proper evaluation of the testicular biopsy of infertile males is very necessary for the management of such patients and pathologists are required to report any form of germ cells seen in the specimen, especially if late spermatids or spermatozoa are seen. Quantitative assessment of human spermatogenesis has been shown by recent studies to be possible and can be beneficial.33

This is very important in offering the chance of assisted fertilization that will require testicular sperm extraction and intracytoplasmic sperm injection, and also for some patients with smaller testicles and slightly elevated levels of FSH.34