Central precocious puberty should be taken seriously in children with Leydig cell tumors of the testis after surgical treatment: a tertiary center experience

Abstract

Central precocious puberty secondary to Leydig cell tumors is rare in children. We retrospectively analyzed the mid- to long-term follow-up data of patients with Leydig cell tumors. The clinical data of 12 consecutive patients who were treated at Beijing Children’s Hospital, Capital Medical University (Beijing, China), between January 2016 and October 2023 were retrospectively reviewed. Clinical evaluations, including physical examination, hormone examination, serum tumor marker analysis, abdominal and scrotal ultrasound, chest X-ray, and bone age measurement, were conducted before surgery and at follow-up time points. Surgical approaches were selected according to the individual conditions. Patients with an abnormal hormonal status and suspected of having central precocious puberty were referred to endocrinologists to confirm the diagnosis. Subsequently, gonadotropin-releasing hormone analog therapy was proposed. The mean patient age was 81.3 (range: 40–140) months at the time of the operation. Ten patients had peripheral precocious puberty at admission. All patients had elevated preoperative testosterone levels, whereas tumor marker levels were normal. Testis-sparing surgery was performed in eleven patients, and radical orchiectomy was performed in one patient. The follow-up duration (mean ± standard deviation) was 36.2 ± 25.3 months. Five patients had central precocious puberty, with a mean duration of 3.4 (range: 1–6) months postoperatively. Three patients were receiving gonadotropin-releasing hormone analog therapy, and good suppression of puberty was observed. No risk factors were found for secondary central precocious puberty. There was a high prevalence of central precocious puberty secondary to Leydig cell tumors in our study. Gonadotropin-releasing hormone analog therapy has satisfactory treatment effects. Larger sample sizes and long-term follow-up are needed in future studies.

INTRODUCTION

Testicular tumors are rare in pediatric populations, with an incidence of 0.5–2 per 100 000 in children and adolescents.1,2 Leydig cell tumors (LCTs) are sex cord-stromal tumors that account for only 4%–9% of all primary testicular tumors in prepubertal males.3 As testosterone-secreting tumors, LCTs often present with isosexual precocious pseudopuberty combined with elevated serum testosterone and reduced gonadotropin levels.

Unilateral LCTs in children are considered benign worldwide, and there are no reports of malignant LCTs in children thus far. Therefore, radical orchiectomy and tumor enucleation are currently accepted treatments for LCTs. Theoretically, after tumor removal, the patient’s testosterone level decreases, and symptoms of precocious pseudopuberty no longer progress. Nevertheless, cases of premature activation of the hypothalamic–pituitary–gonadal (HPG) axis, which leads to central precocious puberty (CPP) following surgical treatment, have occasionally been reported.4,5,6,7

Hence, we retrospectively reviewed and analyzed data from pediatric patients with LCTs treated at Beijing Children’s Hospital, Capital Medical University (Beijing, China). In addition, mid- to long-term follow-up data were obtained. We aimed to increase clinicians’ and patient populations’ understanding of CPP secondary to LCT.

PATIENTS AND METHODS

Patients

The clinical data of patients who were diagnosed with LCTs of the testis and treated at Beijing Children’s Hospital, Capital Medical University, between January 2016 and October 2023 were retrospectively reviewed. Only patients with pathologically confirmed LCTs were included in this study. Patients who were lost to follow-up were excluded. This retrospective chart review study involving human participants was performed in accordance with the ethical standards of the institutional and national research committees and with the Declaration of Helsinki in 1964 and its later amendments or comparable ethical standards. This study was approved by the Ethics Committee of Beijing Children’s Hospital, Capital Medical University (Approval No. [2023]-E-178-R). Individual consent for this retrospective analysis was waived by the Ethics Committee.

Data collection

The following clinical data were recorded: age, weight, clinical symptoms, physical examination, preoperative laboratory parameters (including hormone information and serum tumor markers), preoperative imaging data (abdominal and scrotal ultrasonography, color Doppler flow imaging [CDFI], and chest X-ray), operation side, tumor size, boundary of the mass, histopathological results, and follow-up information (growth and development status, hormone information, abdominal and scrotal ultrasonography, chest X-ray, and outcomes).

Surgical technique

Testis-sparing surgery (TSS) was performed in most patients (11/12). A transverse incision was made in the middle of the scrotum on the affected side. The skin, subcutaneous tissue, and flesh membrane were cut layer by layer, and the tunica vaginalis was opened. The tunica albuginea of the testis was incised, and the tumor was removed entirely along the tumor capsule, leaving the testicular parenchyma. After hemostasis, the tunica albuginea of the testis was sutured. Finally, the testicular tunica vaginalis and scrotal skin were closed. The enucleated mass was submitted for pathological examination.

In one patient, radical orchiectomy was performed, an inguinal incision was made, and the spermatic cord was clamped. The scrotum and tunica vaginalis were then carefully incised, and the affected testis was isolated.

Follow-up

Patients were followed up at the outpatient department or through telephone interviews. Physical examinations were performed at every outpatient visit. Hormonal status was assessed on a regular basis. If abnormal sex hormone levels were detected or symptoms of precocious puberty reappeared, testicular ultrasound was performed to rule out tumor recurrence, and brain magnetic resonance imaging (MRI) was conducted to exclude tumors of the hypothalamus or pituitary gland. Other hormone levels were checked to rule out adrenal dysfunction. Patients who were suspected of having CPP were referred to an endocrinologist to confirm the diagnosis based on basal sex hormone levels or underwent a gonadotropin-releasing hormone (GnRH) stimulation test. Once nonorganic CPP was diagnosed, GnRH analog (GnRHa) therapy was selected. Hormonal profile assessment, physical examination, and bone age (BA) measurement were performed comprehensively to evaluate treatment effects.

Statistical analyses

Categorical data were analyzed using the Chi-square test or Fisher’s exact test, and continuous data were analyzed using the Student’s t-test or Mann-Whitney U test. Univariate logistic analysis was performed to identify risk factors for CPP secondary to LCTs. All P values were two-tailed, and statistical significance was set at P < 0.05. The R programming language and environment for Windows (version 4.2.3; http://www.r-project.org; last accessed on November 8, 2023) was used for analysis. The figure was created using GraphPad Prism (version 9.5.0 for Windows; GraphPad Software, San Diego, CA, USA) and R programming.

RESULTS

Demographic and clinical characteristics

A consecutive series of 12 patients were eventually enrolled in the study. The mean age of the overall cohort at the time of surgery was 81.3 (range: 40–140) months. Most patients (11/12) presented with a painless scrotal mass to the clinic. None of the patients complained of testicular pain. Moreover, 9 (75.0%) patients presented with penis enlargement, with or without pubarche, 5 (41.7%) with growth spurt, 6 (50.0%) with breaking voice, and 6 (50.0%) with acne. Seven patients were affected on the left side and five were affected on the right side, but bilateral legions were not found. Serum testosterone was elevated in all patients, while luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were suppressed and were at the lower end of the normal range for children. Serum tumor markers of all patients were within the normal range.

The tumor size for the entire cohort (mean ± standard deviation [s.d.]) was 2.0 ± 1.0 cm, as measured by preoperative ultrasound. Clear tumor borders and abundant blood flow were observed in all patients. On ultrasound, lesions presented as a single hypoechoic mass with a heterogeneous echoic pattern in all patients.

TSS was performed in 11 (91.7%) patients, one patient underwent radical orchiectomy because the tumor was large (4.2 cm × 2.5 cm × 3.2 cm), and the remaining parenchyma was too thin to distinguish. The macroscopic appearance of the tumor is typically that of a dark yellow-to-brown, well-defined soft mass. All patients had pathologically confirmed LCTs. Follow-up data were obtained for all cohorts, and the follow-up duration (mean ± s.d.) was 36.2 ± 25.3 months. The overall survival (OS) rate was 100.0%, and no recurrence or metastasis was found till the last follow-up.

Patients were divided into two groups according to whether CPP occurred after surgery: the CPP group (n = 5) and the non-CPP group (n = 7). A total of 10 patients developed peripheral precocious puberty (PPP) preoperatively, accounting for 100.0% (5/5) and 71.4% (5/7) of the patients in the two groups, respectively. As shown in Table 1, there were no significant differences in demographic or clinical characteristics between the two groups (all P > 0.05). Through univariate logistic analysis, no risk factors for CPP were found.

Table 1.

Demographics and characteristics of the CPP group and the non-CPP group

Variable	Non-CPP group (n=7)	CPP group (n=5)	P
Age (month), mean (s.d.)	87.1 (34.0)	73.2 (20.5)	0.397
Weight (kg), median (IQR)	28.2 (21.4–36.8)	28.4 (27.0–30.0)	0.808
Operation side, n (%)			0.293
Left	3 (42.9)	4 (80.0)
Right	4 (57.1)	1 (20.0)
Peripheral precocious puberty, n (%)			0.470
No	2 (28.6)	0 (0)
Yes	5 (71.4)	5 (100.0)
Preoperative LDH (U l−1), mean (s.d.)	229 (34.4)	245 (40.6)	0.488
Preoperative LH (IU l−1), n (%)			0.375
<0.1	2 (28.6)	5 (100.0)
0.156	1 (14.3)	0 (0)
Othersa	4 (57.1)	0 (0)
Preoperative FSH (IU l−1), mean (s.d.)	0.3 (0.4)	0.7 (0.4)	0.253
Preoperative testosterone (ng dl−1), mean (s.d.)	380 (465)	328 (109)	0.865
Surgical approach, n (%)			1.000
Radical orchiectomy	1 (14.3)	0 (0)
Testicular spare surgery	6 (85.7)	5 (100.0)
Tumor size (cm), mean (s.d.)	1.9 (1.3)	2.1 (0.4)	0.724
Clear boundary, n (%)	7 (100.0)	5 (100.0)	1.000
Abundant blood flow, n (%)	7 (100.0)	5 (100.0)	1.000
Ki67 (%), mean (s.d.)	7.3 (4.8)	6.8 (4.0)	0.847

^aFour patients in the non-CPP group did not have preoperative luteinizing hormone record. CPP: central precocious puberty; LDH: lactate dehydrogenase; LH: luteinizing hormone; FSH: follicle-stimulating hormone; s.d.: standard deviation; IQR: interquartile range

CPP and management

Five patients developed CPP after surgery (Table 2). The mean interval from surgery to CPP was 3.4 (range: 1–6) months. The symptoms of the patients varied: two patients presented with increased pubic hair, one patient showed increased bilateral testicular volume, one patient presented with increased amounts of beard hair, and the remaining one patient experienced recurrent erections. LH and FSH levels were increased, and abnormal testosterone levels were found. Four patients were confirmed to have CPP based on hormonal status (especially basal LH >0.4 IU l⁻¹), and one was confirmed to have CPP based on the GnRH stimulation test.

Table 2.

Details of central precocious puberty patients

Patient	Interval from surgery to CPP (month)	Therapy	Age (month)		Height (percentile), cm (%)			Weight (percentile), kg (%)			Penis length (cm)			Penis diameter (cm)			Testicular volume (ml)			Tanner stagea
			First visit	Last visit	First visit	Therapy begins	Last visit	First visit	Therapy begins	Last visit	First visit	Therapy begins	Last visit	First visit	Therapy begins	Last visit	First visit, left/right	Therapy begins, left/right	Last visit, left/right	First visit	Therapy begins	Last visit
A	5	Leuprorelin acetate	44	67.5	120 (>97)	125.6 (>97)	135 (>97)	27 (>97)	28.2 (>97)	30.8 (>97)	8.5	11	11	2.5	2.5	2.5	3/6	6/6	4/4	PH2	PH3	PH2
B	6	-	62	68.5	127.3 (>97)	-	132.9 (>97)	29.5 (>97)	-	28.8 (>97)	8	-	8	1.9	-	1.9	9/1	-	5/3	PH2	-	PH2
C	1	-	77	81	126 (75–90)	-	130.9 (90–97)	26 (75–90)	-	25.5 (75–90)	6	-	6	2	-	2	20/3	-	6/3	PH2	-	PH2
D	2	Leuprorelin acetate	89	109	141 (>97)	143.2 (>97)	151.1 (>97)	32 (90–97)	34 (90–97)	38.4 (75–90)	5.5	6.5	7	1.8	1.8	2	5/3	6/5	5/5	PH1	PH1	PH1
E	3	Leuprorelin acetate	94	123	134.8 (75–90)	136.2 (75–90)	150.5 (90–97)	28.7 (50–75)	29.1 (50–75)	36.8 (50–75)	9	9	9	3	3	3	6/3	7/4	8/6	PH2	PH2	PH2

^aTanner stage classified according to the condition of PH. A–E: five patients who developed central precocious puberty after surgery. -: not available; PH: pubic hair; CPP: central precocious puberty

As of the last follow-up visit in this study, three patients (patients A, D, and E) were receiving GnRHa therapy (leuprorelin acetate, 3.75 mg every 28 days), one patient (patient B) was ready to start, and one patient (patient C) was also considered for GnRHa therapy after 6 months of conservative observation. For the three patients (patients A, D, and E) who received GnRHa, their hormonal status (LH, FSH, and testosterone) rapidly decreased to normal levels after administration (Figure 1). It is noteworthy that when patient E was reexamined at around 10 years of age (120 months), the above hormones increased again, which was believed to be due to the patient entering true puberty. The growth rate associated with BA was better suppressed. In addition, the physical examination results of these CPP patients are shown in Table 2. The same good suppression was reflected in height velocity, penis length, penis diameter, testicular volume, and Tanner stage.

Figure 1.

Scatterplots of hormonal profile and bone age of five central precocious puberty patients secondary to Leydig cell tumor before and after surgery: (a) LH levels and age; (b) FSH levels and age; (c) testosterone levels and age; and (d) bone age and age. The positions indicated by arrows are when gonadotropin-releasing hormone treatment was given. A–E: five patients who developed central precocious puberty after surgery; LH: luteinizing hormone; FSH: follicle-stimulating hormone.

DISCUSSION

To our knowledge, our study examines the largest series of pediatric patients with LCTs of the testis with secondary CPP, with a mid- to long-term follow-up. Depending on the nature of LCTs, some patients present primarily with PPP symptoms rather than a testicular mass. Due to a lack of understanding of the characteristics of LCTs, some patients may not be able to get to a clinic for treatment early in the disease course. This difference was more significant in our series, as 10 (83.3%) patients had PPP at admission. The time for PPP to be discovered by children or parents was 2 months to 2 years, while the time for testicular masses was much shorter, ranging from 2 months to 1 year, and a few parents could not even precisely recall the time of PPP onset. However, PPP represents a group of heterogeneous disorders in men, including androgen- or β-human chorionic gonadotropin-producing tumors, McCune–Albright syndrome, various types of congenital adrenal hyperplasia, and true familial male precocious puberty.6,8 In our cohort, a testosterone-secreting testicular mass was suspected to be the cause of PPP due to the typical hormonal status (low LH and FSH with high testosterone), scrotal ultrasonographic findings, and investigations that excluded other possible diseases. In addition to PPP symptoms, a unilateral testicular mass was noticed by 91.7% (11/12) of the patients or their parents, and the remaining patients with PPP were screened through scrotal ultrasound, after which a mass (1.7 cm × 1.0 cm × 1.4 cm) was found. This finding was similar to those of previous case studies, in which some patients’ testicular masses could not be easily detected on physical examination, which emphasizes the importance of scrotal ultrasound.6,9,10

To date, there are no generally accepted risk factors for LCTs. However, at the molecular level, genetic variants of LH receptors and G-protein-coupled receptors have been verified to be associated with pubertal disorders in in vitro assays and animal studies, and a few case studies have also revealed these kinds of molecular abnormalities in human patients.9,11,12 Unfortunately, patients in our series were not tested at the molecular level.

Due to the favorable outcomes of LCTs in children, the TSS technique is a better choice. Several studies have previously reported TSS being performed in prepubertal children with LCTs, and no recurrence or metastasis was found.6,7,13,14 In our series, only one patient was treated with radical orchiectomy because the tumor was too large and the remaining parenchyma was difficult to distinguish. In addition, all the other patients underwent TSS.

Because testosterone has a half-life of less than 30 min in plasma, the testosterone levels of LCT patients should be reduced to within the normal range after tumor resection, regardless of whether the surgical method is tumor enucleation or radical orchiectomy. However, five patients in our series had abnormal testosterone values after surgery. Combined with the basal LH values and GnRH stimulation test results obtained for one patient, we confirmed that these patients had developed CPP. Only a few studies have reported CPP secondary to LCTs of the testis.5,6,7,12,15,16 The reason is currently hypothesized to be that sex steroids decrease sharply once the tumor-secreting lesion has been resected, and a sudden reduction in the feedback inhibition of GnRH and gonadotropins occurs; as a result, the HPG axis is subsequently activated.17,18 Some patients had CPP secondary to PPP in previous cases, and recent studies indicated that patients with significantly advanced BA (>10 years) were more likely to develop this condition, which is similar to the findings in our series.19

In addition to the early appearance of secondary sexual characteristics, the premature height growth and skeletal maturation caused by the persistence of CPP cannot be ignored, which can lead to compromised adult height and depression.20 GnRHa has been considered the gold standard treatment for CPP since the mid-1980s. GnRHa constantly stimulates pituitary gonadotrophs, causing desensitization and reduced release of LH and, to a lesser extent, FSH.21 Treatment efficacy will be monitored by physical examination, BA X-ray, and laboratory assessment. Children with satisfactory pubertal suppression should present with stabilization or regression of physical signs of CPP, decreased height velocity in the prepubertal range, and BA close to chronological age over time. For serum LH levels, some studies have suggested that basal LH measurement can be misleading because LH levels above the prepubertal range do not indicate the absence of suppression of the HPG axis to some extent.22,23 LH levels after injection of GnRH or GnRHa were measured. In our study, three patients with CPP who received GnRHa therapy were monitored via the basal LH test; two of them had satisfactory LH levels during follow-up; and one patient, only after 10 years old, showed a rapid increase in LH levels, which we considered due to the onset of true puberty.

Studies focused on boys with CPP treated with GnRHa are relatively rare. Shim et al.24 recently reported 85 boys with CPP who were treated with leuprolide or triptorelin for more than 2 years. Among them, 20 patients who discontinued treatment were followed up until they reached the final adult height (FAH) and reported that the growth potential and FAH significantly improved after long-term GnRHa treatment. In addition, the specific age cutoffs for average height gain are obtainable for girls but not for boys.18 Currently, there are no accepted standards regarding the timing of discontinuation of GnRHa treatment. Studies have suggested that boys with a BA >14 years cannot achieve a significant increase in adult height with GnRHa treatment.25 It should be assessed individually, considering whether the patient is in the typical age range for puberty and physical status matching their peers.

Our study has some limitations. First, some recall bias is unavoidable because of the nature of retrospective studies and the lack of understanding of the disease by patients and their parents. Second, the sample size is still small, future studies with larger sample sizes are needed to explore issues such as risk factors. Finally, long-term follow-up is necessary to evaluate the effect of GnRHa treatment on FAH.

CONCLUSIONS

Our retrospective study of a series of patients diagnosed with testicular LCT suggested that both TSS and radical orchiectomy have favorable oncological outcomes. However, patients who develop CPP after tumor resection have rarely been reported in previous studies but were common in our series. GnRHa treatment is considered the gold standard therapy for CPP, and a satisfactory treatment effect was observed in our series. In the future, large-sample studies are needed to identify risk factors for secondary CPP, and it is necessary to conduct long-term follow-up to examine the effect of GnRHa on FAH.

AUTHOR CONTRIBUTIONS

PL conceived the study and helped revise the manuscript. ZHL collected and analyzed data and drafted the manuscript. HCS contributed to the conception of the study and helped revise the manuscript. CXG participated in the study design. WPZ contributed to the study design, administrative support, and coordination. All authors read and approved the final manuscript.

COMPETING INTERESTS

All authors declare no competing interests.