Intraoperative ultrasound in the conservative resection of testicular neoplasms

Male Infertility and the Risk of Developing Testicular Cancer: A Critical Contemporary Literature Review

Background and Objectives: The relationship between male infertility (MI) and testicular cancer (TC) is bilateral. On one hand, it is well-established that patients diagnosed with TC have a high risk of pre- and post-treatment infertility. On the other hand, the risk of developing TC in male infertile patients is not clearly defined. The objective of this review is to analyze the histopathological, etiological, and epidemiological associations between MI and the risk of developing testicular cancer. This review aims to provide further insights and offer a guide for assessing the risk factors for TC in infertile men. Materials and Methods: A comprehensive literature search was conducted to identify relevant studies discussing the relationship between MI and the risk of developing TC. Results: The incidence rates of germ cell neoplasia in situ (GCNIS) appear to be high in infertile men, particularly in those with low sperm counts. Most epidemiological studies have found a statistically significant risk of developing TC among infertile men compared to the general or fertile male populations. The concept of Testicular Dysgenesis Syndrome provides an explanatory model for the common etiology of MI, TC, cryptorchidism, and hypospadias. Clinical findings such as a history of cryptorchidism could increase the risk of developing TC in infertile men. Scrotal ultrasound evaluation for testis lesions and microlithiasis is important in infertile men. Sperm analysis parameters can be useful in assessing the risk of TC among infertile men. In the future, sperm and serum microRNAs (miRNAs) may be utilized for the non-invasive early diagnosis of TC and GCNIS in infertile men. Conclusions: MI is indeed a risk factor for developing testicular cancer, as demonstrated by various studies. All infertile men should undergo a risk assessment using clinical examination, ultrasound, and semen parameters to evaluate their risk of TC.

What Is the Malignant Potential of Small (<2 cm), Nonpalpable Testicular Incidentalomas in Adults? A Systematic Review

CONTEXT

Unlike palpable lumps, a large number of nonpalpable testicular lesions found incidentally at ultrasound in asymptomatic postpuberal males are either benign tumours or non-neoplastic lesions. The prevalence of malignancy, however, is appraised based on small case series. Dedicated studies report a large number of patients, and systematic review articles are lacking.

OBJECTIVE

This systematic review is aimed to assess, from the analysis of the pooled data of the available literature, the incidence of benign tumours, malignant tumours, and non-neoplastic lesions, and to identify predictive characteristics for malignancy.

EVIDENCE ACQUISITION

A systematic review of PubMed, Scopus, Google Scholar, Turning Research Into Practice (TRIP) database, and the Cochrane Library was conducted on January 6, 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Studies were retrieved reporting on adult asymptomatic men, with single, incidentally identified small testicular lesions, either fertile or infertile, with negative tumour markers and without specific risk factors for malignancy. Lesions ≤20 mm were considered small. Seventy-four studies were selected for inclusion in this analysis. Twenty-six additional publications have been retrieved by the bibliography quoted in the selected articles.

EVIDENCE SYNTHESIS

Pooled data of 1348 lesions in 1348 patients were collected. Of these lesions, 408 could be retrieved individually, 44.6% were benign, 27.2% were malignant, and 20.8% were non-neoplastic. Virtually all lesions <3 mm and 86.6% of lesions <5 mm were benign. Lesions >10 mm have a 38.14% probability of being benign. Hyperechoic lesions are likely benign. Fertility status does not affect the risk of malignancy.

CONCLUSIONS

Very small (<3 mm) and small (<5 mm) incidentally detected testicular lesions in asymptomatic postpuberal men with normal tumour markers could be frequently benign. More prospective studies are needed to better support this finding. Management strategies should be developed for these patients to reduce overtreatment.

PATIENT SUMMARY

Small testicular lesions are incidentally founded at ultrasound. It is not easy to distinguish a benign lesion from a malignant one. Results of this study are reporting a higher incidence of benign lesions with a diameter of <5 mm. More studies are needed to better understand the biology and the management strategy for small testicular lesions.

Prevalence and Management of Incidental Testicular Masses-A Systematic Review

Management of incidentally diagnosed small testicular masses (STM) is controversial. Although there is the risk of malignancy, it might be realistic to safely seek preservation of testicles bearing benign masses. This study aims to systematically evaluate the evidence regarding prevalence of STMs, their benign or malignant histology and their management. We conducted a systematic literature search for studies reporting small or incidental testicular masses and their management by radical orchiectomy, testis sparing surgery (TSS) or ultrasound (US) surveillance. We initially screened 2126 abstracts and from these, 57 studies met the inclusion criteria. Testicular masses were detected in 1.74% of patients undergoing US examination. Regarding STMs removed by surgery, 41.12% were benign. Intraoperative frozen section examination (FSE) is a reliable tool to discriminate between benign and malignant testicular masses (average 93.05% accuracy), supporting TSS. Benign lesions were associated with smaller diameter (<1 cm 68.78% benign), were often hypoechoic and exhibited regular margins on US. Conclusions: Small testicular masses are often benign. Clinical and US patterns are not accurate enough for including patients in surveillance protocols and TSS paired with FSE is pivotal for precluding the removal of testicles bearing benign lesions. Future research might unveil new imaging tools or biomarkers to support clinical management.

Incidental testicular masses and the role of organ-sparing approach

OBJECTIVES

The widespread use of ultrasonography for the investigation of common urological conditions, such as infertility or pain, has resulted in an increased incidence of incidental non-palpable testicular masses. The majority of these are expected to be benign therefore a conservative approach, either active monitoring or organsparing approach, is recommended. However, there are no clinical or radiological parameters which define the exact nature of such lesions and optimal patient selection criteria are lacking. In this comprehensive review we discuss the significance of incidental, small testicular masses (STMs) and the role of organ-sparing approach in the management of these lesions.

MATERIALS AND METHODS

A non-systematic search was performed using PubMed to identify articles that covered the following topics; clinical implications at diagnosis, role of imaging in identifying the malignant capabilities of a lesion, role of surgery and the final pathology.

RESULTS

Incidental STMs are routinely identified following ultrasound examination of infertile men. STMs usually measure a few millimeters in size and the majority of these are benign. Therefore, strict follow up or an organ-sparing approach, with utilisation of frozen section analysis (FSA), is favored for STMs. FSA has a high correlation with final pathology and prevents unnecessary orchidectomies. Advances in imaging, namely ultrasound and magnetic resonance imaging may provide enhanced assessment of STMs and guidance intraoperatively.

CONCLUSIONS

The optimal approach is not well defined and there is no specific clinical parameter that can predict the nature of STMs. The increasing incidence of small, benign testicular masses has resulted in the development of organ-sparing surgery to investigate and manage these lesions. Organ-sparing surgery has been shown to be practical and carries excellent oncological outcomes.

The role of radiological surveillance in the conservative management of incidental small testicular masses: A systematic review

Objective: The increasing use of scrotal ultrasonography (US) for non-cancerous indications has led to greater detection of incidental, small testicular masses. Operative intervention is currently the mainstay of treatment for all testicular tumours; however, despite the low malignant potential of small, incidental masses, little is known about conservative management using radiological surveillance.

Methods: A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted and studies meeting the inclusion criteria were reviewed for patient outcomes.

Results: A total of 293 patients across six studies underwent radiological surveillance for an incidental small testicular mass. Infertility was the main indication for investigation and all studies used US as the surveillance modality. A total of 37 patients (12.6%) underwent surgical exploration during follow-up, with only 10 (3.4%) found to have malignant disease at histology.

Conclusions: Radiological surveillance of incidental small testicular masses is safe when used for select patient groups due to the high probability of benign disease, although optimal patient selection criteria and a well-defined protocol are lacking. This approach could be considered in patients with incidental, impalpable testicular masses of ≤5 mm in diameter displaying no significant size increase or internal vascularity on US and with negative tumour markers, as the probability of malignancy in these patients is low.

Detection of small testicular masses in monorchid patients using US, CPDUS, CEUS and US-guided biopsy

PURPOSE

Testis sparing surgery (TSS) is a well-known technique in the treatment of small testicular masses. Grayscale ultrasound (US), color/power Doppler US (CPDUS) and contrast-enhanced ultrasound (CEUS) are considered the best diagnostic imaging tools in those patients. Aim of this study was to assess the role of US imaging in the detection of small testicular masses in monorchid patients after orchiectomy for malignant neoplasm, and in guiding surgery to reach the target and also to differentiate lesions which presented vascular activity within the mass.

METHODS

From January 2011 to October 2014, 18 patients were enrolled in this study. They had previously undergone orchiectomy and were investigated for suspected contralateral disease. During routine follow-up, all patients underwent grayscale US. If findings were positive, CPDUS and CEUS were performed and eventually all patients underwent surgery. After exteriorization of the testis, the small mass was identified by intraoperative US, and a needle was placed under US guidance. After excision of the mass, frozen section examination was performed. When malignancy was found, radical orchiectomy was performed; if histological outcome was negative, the healthy testis was conserved.

RESULTS

All patients underwent grayscale US examination, which showed small hypoechoic masses. Each mass identified at US imaging was confirmed at surgery. All patients underwent CPDUS; 12/19 lesions showed blood flow while 7/19 showed absence of blood flow. At CEUS, 16/19 lesions showed enhancement and subsequent histological examination revealed that 8 were seminomas and 3 were Leydig cell tumors. In 5/19 cases CEUS showed the presence of lesions (focal inflammatory lesions) and in 3/19 cases CEUS was negative.

CONCLUSIONS

TSS in monorchid patients may be a safe procedure leading to excellent results. We therefore consider it a valid alternative to radical orchiectomy, and US imaging is essential to guide the resection of non-palpable neoplasms and to exclude concomitant lesions.

Testicular epidermoid cyst

Epidermoid cyst of the testis is a benign, non-teratomatous tumour. It is often possible to make the diagnosis pre-operatively, combining typical sonographic features with normal biochemical tumour markers. The accurate pre-operative diagnosis will allow for testis-sparing surgery and prevent unnecessary orchiectomy. An 11-year-old boy with testicular epidermoid cyst who presented with pain in testis was presented in this report.

[Non palpable testicular tumors. Retrospective series]

OBJECTIVE

To report our experience in 13 cases with nonpalpable testicular tumors and review the literature.

MATERIAL AND METHODS

From 1998 to 2012, 13 patients were diagnosed with nonpalpable testicular tumors. The data base was performed prospectively, and analyzed retrospectively. We evaluated demographic data, clinical presentation, ultrasound tumor features, tumor markers, frozen and final histopathological findings. All patients were also evaluated with serum tumor markers and the surgical approach was inguinal.

RESULTS

The mean age was 46.4 years and the most frequent clinical presentation were orchialgia in six patients (46.1%) and infertility in three (23%). All masses were hypoechoic with an average tumor size of 8.9 mm. The serum tumor markers were negative in all patients and the final histopathological findings were six seminomas, two embryonal carcinomas, one seminiferous tubules atrophy, a segmental testicular infarction, a Sertoli cell tumor and a Leydig cell tumor.

CONCLUSIONS

Nonpalpable testicular masses were benign in almost half of the cases; therefore, we recommend using the frozen section pathology as a tool to perform conservative surgery in selective cases.

Microsurgical testis-sparing surgery in small testicular masses: seven years retrospective management and results

OBJECTIVE

To retrospectively evaluate the clinical outcomes of 20 patients diagnosed with a nonpalpable or small testicular mass (2 cm) at 2 academic urological department. Testis-sparing surgery (TSS) is currently performed routinely for the management of nonpalpable testicular masses. High reliability of frozen section examination (FSE) and high-frequency ultrasound (US) and the adoption of microsurgical techniques improved safety and feasibility of this technique.

METHODS

From January 2004 to March 2011, 23 patients underwent microsurgical TSS. An inguinal approach was performed in 22 cases and a suprapubic incision in one bilateral case. All procedures were performed with an operating microscope, with warm ischemia in 21 cases and cold ischemia in 2 cases. Intraoperative US was performed before opening the albuginea. Mean operative time was 89 minutes.

RESULTS

After mass excision, FSE was performed; only 2 seminomatous tumors were identified, and the remaining masses were benign lesions. After a mean follow-up >12 months, all patients are free of disease; no hypogonadism developed.

CONCLUSIONS

TSS performed using an operating microscope allowed the preservation of testes for 21 patients diagnosed with small testicular and/or nonpalpable mass (<2 cm), without evidence of disease recurrence or de novo onset. This approach could be mandatory in the treatment of bilateral tumors or in solitary testis. Maintaining fertility is not the main goal of TSS because a great number of patients affected by testicular tumors are already infertile. Esthetic outcomes and sparing hormonal function are the main reasons for TSS.

Testis-sparing surgery for benign and malignant tumors: A critical analysis of the literature

In order to explore the latest advances in organ-sparing treatment of testicular tumors, a literature search of the Medline/PubMed database was carried out for published data in the English language up to 2007.

In the recent past the management of testicular tumors has evolved in favor of a testis-sparing approach in selected cases, both in the adult and pediatric population. The widespread use of high-frequency testicular ultrasound has led to detecting an increasing number of asymptomatic, non-palpable, small-volume masses. A higher proportion of testicular lesions of benign nature than previously reported has now been documented. The high accuracy of frozen section examination and the increasing interest in the potential functional, psychological and cosmetic advantages related to preserved testicular parenchyma are other arguments currently favoring the adoption of an organ-sparing policy for most testicular masses. Greater experience has been gained in also managing conservatively malignant tumors. Patients with germ-cell cancer in solitary testis or bilateral tumors can be submitted to testis-sparing surgery, provided that the maximum size of the lesion is <2 cm, preoperative testosterone is normal and adjuvant radiotherapy of the residual parenchyma is delivered. Cancer-specific survival is excellent, local recurrence rate very low and androgen supplementation unlikely.

Ultrasound guided location and resection of a suburothelial cavernous haemangioma of the bladder

Complete endoscopic resection of bladder tumours can be difficult. This is particularly true when there is normal overlying mucosa, as in a cavernous haemangioma. We describe a case where intraoperative ultrasound was used to guide successful endoscopic resection.

High prevalence of testicular cancer in azoospermic men without spermatogenesis

BACKGROUND

An increased risk of testicular cancer in men with infertility and poor semen quality has been reported. Our aim was to investigate the prevalence of testicular nodules and cancer in azoospermic subjects with different spermatogenetic patterns.

METHODS

A total of 1443 consecutive infertile men were investigated, out of which 145 (10.0%) were found to be azoospermic. By using clinical examination and testicular ultrasound, 11 out of the 145 patients showed testicular nodules (2.8-26 mm). To obtain spermatozoa for assisted reproduction, 97 subjects required testicular sperm extraction (TESE) and biopsy, including the 11 patients with nodules. They were divided into two groups according to biopsy results: Group A (n = 38) with complete Sertoli cell-only syndrome (SCOS) and Group B (n = 59) with varying spermatogenetic patterns. Ten nodules were found in Group A and one in Group B.

RESULTS

In azoospermic men, the overall prevalence of nodules was 7.5%. In complete SCOS, the prevalence of nodules and cancer was 10/38 (26.3%) and 4/38 (10.5%), respectively. Amongst the cancers, one embryonal carcinoma, one seminoma and two in-situ carcinomas were found.

CONCLUSION

The prevalence of testicular nodules and cancer in azoospermic men with complete SCOS is very high. In these subjects, the role of clinical evaluation, ultrasound and biopsy should be emphasized.

Management of nonpalpable incidental testicular masses

PURPOSE

We report on 4 patients who presented with nonpalpable testicular masses discovered on scrotal ultrasound, and offer treatment recommendations based on our experience and a review of the literature.

MATERIALS AND METHODS

Four patients underwent intraoperative ultrasound guided localization and excisional biopsy of nonpalpable testicular parenchymal masses. Radical orchiectomy was performed in 2 patients because of testicular cancer. Patient age, clinical presentation, ultrasound results, frozen section and permanent pathology results are reported.

RESULTS

During a 3-year period 1,040 scrotal ultrasounds were performed for indications other than retroperitoneal mass at a single institution, and nonpalpable testicular parenchymal masses were discovered in 4 patients with an age range of 22 to 31 years. Testis mass size ranged from 5 to 6 mm in maximum diameter and serum tumor markers were negative in all patients. Frozen section pathology indicated benign lesions in all patients and permanent pathology revealed seminoma in 2 of the patients who underwent delayed radical orchiectomy. Permanent pathology of orchiectomy specimens did not reveal residual invasive tumor.

CONCLUSIONS

Intraoperative ultrasound guided localization and excisional biopsy is a reasonable treatment option for patients with nonpalpable incidental testicular masses. Excisional biopsy with margins that show normal testicular tissue is essential in testis sparing surgery and patients must be cautioned that final pathology may indicate the need for delayed radical orchiectomy.

Management of nonpalpable testicular tumors

OBJECTIVES

To report our series of nonpalpable testicular tumors with a review of published studies. Radical orchiectomy remains the reference standard in the treatment of a solid testicular mass. Testis-sparing surgery has recently been advocated for a select group of patients with nonpalpable tumors.

METHODS

Between 1998 and 2002, a nonpalpable testicular mass was discovered in 9 patients. Ultrasonography was performed for infertility evaluation (5 patients), testicular pain (3 patients), and retroperitoneal lymphadenopathy (1 patient).

RESULTS

Radical orchiectomy was performed in 7 of 9 patients and testis-sparing surgery with microsurgical excision of tumor in 1 patient. One patient decided against surgery. A benign testicular tumor was found in 6 and a malignant tumor in 2 of the 8 patients.

CONCLUSIONS

A high incidence of benign nonpalpable tumor and an advanced microsurgical technique justifies organ-sparing surgery as an alternative for radical orchiectomy in a select group of patients. Testicular preservation in patients with a malignant nonpalpable testicular tumor is a feasible, but still controversial, approach.

Frozen section analysis-guided organ-sparing approach in testicular tumors: technique, feasibility, and long-term results

OBJECTIVES

To evaluate retrospectively the indications, surgical technique, feasibility, and follow-up data of our frozen section analysis-guided organ-sparing approach to small testicular tumors. Removal of a solitary testis or bilateral orchiectomy for testicular neoplasm results in androgen deprivation and infertility. Moreover, removal of a testis for benign lesions is to be avoided. Organ-sparing surgery aims at preserving enough testicular parenchyma to maintain physiologic endocrine function and, if possible, fertility.

METHODS

Tumors of 25 mm or less in diameter were managed by an organ-sparing approach. Normal preoperative plasma levels of luteinizing hormone and testosterone were a prerequisite. After localization of the tumor by ultrasonography and accurate staging, organ-sparing surgery was performed under cold ischemia. Frozen section analyses of the tumor and tumor bed biopsies were obtained. In the case of malignant germ cell tumor with a normal contralateral testis, ablation of the tumor-bearing testis was performed.

RESULTS

A total of 32 organ-preserving procedures were performed in 30 patients without any complications. Local recurrence was observed in 1 patient who refused to undergo local radiotherapy for concomitant testicular intraepithelial neoplasia; repeat organ-sparing surgery was performed in this patient. After organ-sparing surgery, ablation of the remaining testis was performed in 1 patient because of positive margins on final histologic analysis and in another patient because of endocrine insufficiency. In all other patients, the serum testosterone levels remained within normal limits. No retroperitoneal, pulmonary, or other recurrences were encountered; all patients were free of disease at a mean follow-up of 46.3 months.

CONCLUSIONS

The organ-sparing frozen section analysis-guided approach to testicular masses represents a promising treatment alternative to orchiectomy in selected patients with bilateral malignant testicular tumors, tumors in a solitary testis, or unilateral or bilateral benign tumors. The technique is oncologically efficient, lifelong hormonal substitution can be prevented, and, in some patients, even fertility may be preserved, provided certain criteria concerning patient selection and surgical technique are observed.

Organ sparing surgery for malignant germ cell tumor of the testis

PURPOSE

We evaluate the indication, technique and long-term outcome of organ preserving tumor resection rather than standard orchiectomy in 73 patients with bilateral testicular germ cell tumors or tumors of a solitary testicle.

MATERIALS AND METHODS

Tumor resection was performed in 73 patients with 52 and 17 metachronous and synchronous bilateral testicular germ cell tumors, respectively, and 4 testicular germ cell tumors of a solitary testicle. Histology of the enucleated germ cell tumor revealed seminoma in 42 (57.5%) patients, embryonal carcinoma in 14 (19.2%), mature teratoma in 11 (15.1%), and mixed and combined germ cell tumors in 6 (8.2%). Mean tumor diameter was 15 mm. (range 5 to 30). Associated testicular intraepithelial neoplasia was diagnosed in 82% of patients who underwent local radiation with 18 Gy.

RESULTS

After a median followup of 91 months (range 3 to 191) 72 (98.6%) patients had no evidence of disease and 1 died of systemic tumor progression. No local relapse occurred in 46 patients with associated testicular intraepithelial neoplasia treated with local radiation. However, local recurrence did develop in 4 patients after 3, 6, 12 and 165 months without radiation but all survived after undergoing inguinal orchiectomy. Testosterone levels were normal in 62 (84.9%) patients, hypogonadism developed in 7 (9.6%) and preoperative levels remained low in 4 (5.5%). Of the 10 patients who postponed local radiation for paternity reasons 5 had successfully fathered a child after organ sparing surgery.

CONCLUSIONS

After a long-term followup of greater than 7 years organ sparing surgery represents a viable therapeutic approach to bilateral testicular germ cell tumor with an excellent postoperative outcome. Tumor enucleation might be considered a standard approach if the guidelines are respected, including cold ischemia, organ confined tumor less than 20 mm., multiple biopsies of the tumor bed, adjuvant local irradiation postoperatively to avoid local recurrence, close followup and high compliance.

Organ preservation for the treatment of contralateral testicular seminoma

PURPOSE

Local excision of germ cell tumor in the remaining testicle followed by a modest dose of irradiation is an alternative to orchiectomy. This organ sparing technique provides superior quality of life and reduces the need for lifelong hormone replacement.

MATERIALS AND METHODS

We treated two patients with contralateral seminomas with organ preservation. Both patients received postoperative irradiation to the remaining testicle to a dose of 20 Gy in 10 fractions and 19.8 Gy in 11 fractions.

RESULTS

Both patients are alive with no evidence of disease more than 3 years since the completion of their treatments. They both have reduced but preserved androgen production and retained their virility. They both are azospermic.

CONCLUSION

We conclude that organ preservation for the treatment of contralateral testicular seminoma is a superior alternative to orchiectomy of the remaining testicle. It preserves male hormone production with equal survival outcome expectations.

Rodent Leydig cell tumorigenesis: a review of the physiology, pathology, mechanisms, and relevance to humans

Leydig cells (LCs) are the cells of the testis that have as their primary function the production of testosterone. LCs are a common target of compounds tested in rodent carcinogenicity bioassays. The number of reviews on Leydig cell tumors (LCTs) has increased in recent years because of its common occurrence in rodent bioassays and the importance in assessing the relevance of this tumor type to humans. To date, there have been no comprehensive reviews to identify all the compounds that have been shown to induce LCTs in rodents or has any review systematically evaluated the epidemiology data to determine whether humans were at increased risk for developing LCTs from exposure to these agents. This review attempts to fill these deficiencies in the literature by comparing the cytology and ontogeny of the LC, as well as the endocrine and paracrine regulation of both normal and tumorigenic LCs. In addition, the pathology of LCTs in rodents and humans is compared, compounds that induce LC hyperplasia or tumors are enumerated, and the human relevance of chemical-induced LCTs is discussed. There are plausible mechanisms for the chemical induction of LCTs, as typified by agonists of estrogen, gonadotropin releasing hormone (GnRH), and dopamine receptors, androgen receptor antagonists, and inhibitors of 5alpha-reductase, testosterone biosynthesis, and aromatase. Most of these ultimately involve elevation in serum luteinizing hormone (LH) and/or LC responsiveness to LH as proximate mediators. It is expected that further work will uncover additional mechanisms by which LCTs may arise, especially the role of growth factors in modulating LC tumorigenesis. Regarding human relevance, the pathways for regulation of the hypothalamo-pituitary-testis (HPT) axis of rats and humans are similar, such that compounds that either decrease testosterone or estradiol levels or their recognition will increase LH levels. Hence, compounds that induce LCTs in rats by disruption of the HPT axis pose a risk to human health, except for possibly two classes of compounds (GnRH and dopamine agonists). Because GnRH and prolactin receptors are either not expressed or are expressed at very low levels in the testes in humans, the induction of LCTs in rats by GnRH and dopamine agonists would appear not to be relevant to humans; however, the potential relevance to humans of the remaining five pathways of LCT induction cannot be ruled out. Therefore, the central issue becomes what is the relative sensitivity between rat and human LCs in their response to increased LH levels; specifically, is the proliferative stimulus initiated by increased levels of LH attenuated, similar, or enhanced in human vs. rat LCs? There are several lines of evidence that suggest that human LCs are quantitatively less sensitive than rats in their proliferative response to LH, and hence in their sensitivity to chemically induced LCTs. This evidence includes the following: (1) the human incidence of LCTs is much lower than in rodents even when corrected for detection bias; (2) several comparative differences exist between rat and human LCs that may contribute, at least in part, to the greater susceptibility of the rat to both spontaneous and xenobiotic-induced LCTs; (3) endocrine disease states in man (such as androgen-insensitivity syndrome and familial male precocious puberty) underscore the marked comparative differences that exist between rats and man in the responsiveness of their LC's to proliferative stimuli; and (4) several human epidemiology studies are available on a number of compounds that induce LCTs in rats (1,3-butadiene, cadmium, ethanol, lactose, lead, nicotine) that demonstrate no association between human exposure to these compounds and induction of LC hyperplasia or adenomas. (ABSTRACT TRUNCATED)

Leydig cell hyperplasia and adenoma formation: mechanisms and relevance to humans

Leydig cell adenomas are observed frequently in studies evaluating the chronic toxicity of chemical agents in laboratory animals. Doubts have been raised about the relevance of such responses for human risk assessment, but the question of relevance has not been evaluated and presented in a comprehensive manner by a broad group of experts. This article reports the consensus conclusions from a workshop on rodent Leydig cell adenomas and human relevance. Five aspects of Leydig cell biology and toxicology were discussed: 1) control of Leydig cell proliferation; 2) mechanisms of toxicant-induced Leydig cell hyperplasia and tumorigenesis; 3) pathology of Leydig cell adenomas; 4) epidemiology of Leydig cell adenomas; and 5) risk assessment for Leydig cell tumorigens. Important research needs also were identified. Uncertainty exists about the true incidence of Leydig cell adenomas in men, although apparent incidence is rare and restricted primarily to white males. Also, surveillance databases for specific therapeutic agents as well as nicotine and lactose that have induced Leydig cell hyperplasia or adenoma in test species have detected no increased incidence in humans. Because uncertainties exist about the true incidence in humans, induction of Leydig cell adenomas in test species may be of concern under some conditions. Occurrence of Leydig cell hyperplasia alone in test species after lifetime exposure to a chemical does not constitute a cause for concern in a risk assessment for carcinogenic potential, but early occurrence may indicate a need for additional testing. Occurrence of Leydig cell adenomas in test species is of potential concern as both a carcinogenic and reproductive effect if the mode of induction and potential exposures cannot be ruled out as relevant for humans. The workgroup focused on seven hormonal modes of induction of which two, GnRH agonism and dopamine agonism, were considered not relevant to humans. Androgen receptor antagonism, 5 alpha-reductase inhibition, testosterone biosynthesis inhibition, aromatase inhibition, and estrogen agonism were considered to be relevant or potentially relevant, but quantitative differences may exist across species, with rodents being more sensitive. A margin of exposure (MOE; the ratio of the lowest exposure associated with toxicity to the human exposure level) approach should be used for compounds causing Leydig cell adenoma by a hormonal mode that is relevant to humans. For agents that are positive for mutagenicity, the decision regarding a MOE or linear extrapolation approach should be made on a case-by-case basis. In the absence of information about mode of induction, it is necessary to utilize default assumptions, including linear behavior below the observable range. All of the evidence should be weighed in the decision-making process.

A review of drug-induced Leydig cell hyperplasia and neoplasia in the rat and some comparisons with man

This paper describes control of normal Leydig cell function and testosterone production. The macroscopic and histopathological appearances of spontaneous Leydig cell hyperplasias and tumors (LCT) in the rat are reviewed together with their incidence and hormonal status. Drugs which induce LCTs in chronic studies are discussed and include busereline, carbamazepine, cimetidine, finasteride, flutamide, gemfibrozil, histrelin, hydralazine, indomethacin, isradipine, lactitol, leuprolide, metronidazole, mesulergine, nafarelin, norprolac and vidarabine. The known mechanisms of LCT induction in the rat are reviewed together with other possible etiological factors. The incidence, clinical picture and etiological factors of LCTs in man are also surveyed. Hormone production in Leydig cells and LCTs in rats and man are compared. Differences between the two species are considered, particularly with regard to Leydig cell control mechanisms. The paper concludes that drug-induced LCTs in rats are most probably not predictive for man and their occurrence has little relevance in human safety assessment.

A conservative approach to bilateral testicular germ cell tumors

We report on 6 patients with bilateral testicular germ cell tumors treated by organ sparing surgery. Tumors 6 to 30 mm. in diameter were enucleated, and biopsies of the tumor bed and peripheral parenchyma were taken. Histological examination revealed seminoma in 4 cases, embryonal carcinoma in 1 and a Leydig cell tumor in 1. All patients underwent testicular radiation therapy with 20 Gy. for carcinoma in situ. A testicular biopsy was performed 6 months postoperatively to evaluate therapeutic success. Median followup was 43 months, all patients were free of disease and there was no local recurrence. Luteinizing hormone and testosterone were within the normal range and no androgen substitution was necessary. Our study suggests that organ sparing surgery for bilateral testicular germ cell tumors represents a new therapeutic approach with endocrinological and psychological advantages. In our experience conservative surgery is possible under certain prerequisites, including organ confined tumor without infiltration of the rete testis, obtaining multiple biopsies of the tumor bed and peripheral parenchyma, associated carcinoma in situ treated by radiation therapy and close followup of patients.

Organ preserving surgery of malignant germ cell tumors

If a tumor arises in a solitary testis the patient loses fertility and requires lifelong androgen substitution. We describe the technique and results of organ preserving enucleation resection performed in 14 patients. The tumor was excised under (cold) ischemia via a mini-surgical technique using 2-fold magnification and blood vessels were localized intraoperatively by Doppler sonography. The procedure was successful in 10 of 14 patients. In 2 patients the organ required ablation later because of insufficient blood supply. Two patients had subnormal testosterone levels after treatment. There were no local recurrences. Prerequisites for this type of treatment are detailed knowledge of the vascular anatomy of the testis, tumor not too close to the rete testis, largest diameter 20 mm. or less, normal preoperative plasma testosterone level, postoperative local irradiation with 20 Gy., followup biopsies and hormonal status obtained 6 months after enucleation resection, and meticulous followup for early detection of local recurrences or systemic progression.

Fibrotic lesions of the testicle: sonographic patterns mimicking malignancy

All testicular sonograms performed over a 2.5-year period were retrospectively reviewed, yielding eight patients with pathologically proven lesions consisting primarily of tubular sclerosis and interstitial fibrosis. Only two patients (25%) had a palpable abnormality. A variety of sonographic patterns was found, including focal hypoechoic or hyperechoic lesions and diffuse heterogeneity of the testicular parenchyma. The clinical and sonographic findings prompted open biopsy or orchiectomy in all cases. In the same time period, nine pathologically proven testicular malignancies were evaluated sonographically and displayed either well-defined hypoechoic or diffusely heterogeneous echo patterns. All but two of these patients (78%) had palpable abnormalities. This study demonstrates a significant overlap in the sonographic appearance of benign fibrotic lesions and testicular malignancies. When careful palpation of a sonographically heterogeneous or focal hypoechoic lesion fails to reveal a mass and serum tumor markers are negative, an open biopsy with frozen section analysis should be considered rather than proceeding directly to orchiectomy. Homogeneously hyperechoic masses can be considered benign and do not require surgery.

Intraoperative ultrasonographically guided biopsy in testicular sarcoidosis: a case report

We present a case of sarcoidosis with involvement of a solitary testis that was discovered incidentally on an ultrasonogram of the scrotum. This appears to be case 8 of sarcoidosis with genitourinary involvement limited to the testis. We believe it is the second report of intraoperative ultrasonography used to locate and perform a biopsy of impalpable testicular lesions. We consider this technique to be useful in instances of solitary gonads or in cases of bilateral lesions.