|Year : 2020 | Volume
| Issue : 1 | Page : 7-12
Grossing and reporting of testicular tumor specimens : An evidence-based approach
Asawari Ambekar1, Vishal Rao2, Sanjay A Pai3, MR Bindhu4, Divya Midha5, Seema Kaushal6, Sachin Patil7, Rakhi Jagdale7, Shailesh Soni8, Bijal Kulkarni9, Sandhya Sundaram10, Ramani Manoj Kumar11, Sangeeta Desai12, Santosh Menon12
1 Department of Pathology, Apollo Hospitals, Navi Mumbai, Maharashtra, India
2 Department of Pathology, Basavatarakam Indo American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
3 Department of Pathology, Columbia Asia Referral Hospital, Bangalore, Karnataka, India
4 Department of Pathology, Amrita Institute of Medical Sciences, Kochi, Kerala, India
5 Tata Medical Center, Kolkata, West Bengal, India
6 Department of Pathology, All India Institutes of Medical Sciences, New Delhi, India
7 Department of Pathology, Shri Siddhivinayak Ganapati Cancer Hospital, Miraj, Maharashtra, India
8 Department of Pathology, Muljibhai Patel Urological Hospital, Nadiad, Gujarat, India
9 Department of Pathology, Kokilaben Dhirubhai Ambani Hospital and Research Centre, Mumbai, Maharashtra, India
10 Department of Pathology, Sri Ramachandra Institute of Higher Education and Research, Chennai, India
11 Department of Pathology, Christian Medical College, Vellore, Tamil Nadu, India
12 Department of Pathology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India
|Date of Submission||27-Dec-2019|
|Date of Decision||09-Jan-2020|
|Date of Acceptance||11-Jan-2020|
|Date of Web Publication||26-Feb-2020|
Department of Pathology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
The majority of testicular tumors are germ cell tumors (GCTs), but there are numerous other types, making testicular tumors one of the most diverse areas of human pathology, despite their relative rarity. Testicular tumors are usually diagnosed only after radical surgery, as biopsies are not performed. Further management of the patient is dependent on the diagnosis at microscopy, which itself is based on the sections taken at the time of grossing the specimen. Many pathologists often aren't well versed with guidelines for handling of orchiectomy specimens and for microscopy. This article discusses, in detail, the approach to grossing of a testicular tumor specimen and elaborates of the reasons as to why we do what we do at the initial “cut-up”. It explains the logic behind the reporting guidelines for testicular tumors and offer a clinical primer to the pathologist as to why we do what we do while grossing testicular tumor specimens.
Keywords: Grossing, orchiectomy, reporting, testis
|How to cite this article:|
Ambekar A, Rao V, Pai SA, Bindhu M R, Midha D, Kaushal S, Patil S, Jagdale R, Soni S, Kulkarni B, Sundaram S, Kumar RM, Desai S, Menon S. Grossing and reporting of testicular tumor specimens : An evidence-based approach. Indian J Cancer 2020;57:7-12
|How to cite this URL:|
Ambekar A, Rao V, Pai SA, Bindhu M R, Midha D, Kaushal S, Patil S, Jagdale R, Soni S, Kulkarni B, Sundaram S, Kumar RM, Desai S, Menon S. Grossing and reporting of testicular tumor specimens : An evidence-based approach. Indian J Cancer [serial online] 2020 [cited 2020 Apr 1];57:7-12. Available from: http://www.indianjcancer.com/text.asp?2020/57/1/7/279168
| » Introduction|| |
Testicular cancer represents 1% of male neoplasms and 5% of urological tumors. Majority of testicular tumors are germ cell tumors (GCTs), but there are numerous other types, making testicular tumors one of the most diverse areas of human pathology, despite their relative rarity. Surgery is the mainstay of the treatment in disease localized to the testis and when metastatic, the management is multimodal, including chemotherapy and radiation therapy. Bone marrow transplantation is reserved for refractory cases.
The surgical treatment is an orchiectomy. Owing to the relative rarity of these tumors, pathologists are not well versed with handling of the orchiectomy specimens and reporting guidelines, especially as to what is the clinical relevance of the pathological parameters.
This article intends to discuss the principles of reporting guidelines of testicular tumors, mainly germ cell tumors, which forms the basis for the management of GCT and their prognostication.
| » Clinical information|| |
The relevant clinical details are essential to render a correct diagnosis and to initiate appropriate management of testicular germ cell tumors.
These include important data such as patient demographics, (especially age), laterality, the type of specimen (biopsy, simple or radical orchiectomy, lymphadenectomy, or post-chemotherapy residual mass excision), the anatomical origin of lymph nodes, and histopathology of any prior excised testicular tumors and treatment. It is well known that prepubertal teratoma and pure yolk sac tumor (YST) occur in the age group of 1–4 years and that spermatocytic tumor and lymphomas generally occur in the elderly more than 60 years of age. The mean age of seminoma is around 40 years and is 5–10 years more than nonseminomatous tumors, although a significant overlap exists.
It should be noted that, although, any tumor can occur at any age, one should carefully consider all the details before diagnosing pure yolk sac tumor in adults, seminoma in teenagers, and germ cell tumors (GCT) in elderly patients.
For testicular cancers, serum tumor markers are of utmost value for diagnosis (before orchiectomy) as well as for prognosis (after orchiectomy). The risk stratification of testicular germ cell tumors is done by the International Germ cell Consensus Classification in the clinic and guides the therapy, postorchiectomy. This is based on the postoperative levels of serum tumor markers, primary site of germ cell tumor, and sites of metastasis. Based on these parameters, seminomas are classified as good risk and intermediate risk, whereas nonseminomatous tumors have good, intermediate, and poor risk categories. The following markers should be determined before, and 5–7 days after orchiectomy:
- Alpha fetoprotein (AFP) (produced by yolk sac cells);
- Human chorionic gonadotropin (HCG) (expression of trophoblastic nature)—it must be noted here that pure seminomas may have raised beta-HCG owing to the presence of syncytiotrophoblastic cells;
- Lactate dehydrogenase (LDH).
The knowledge of preoperative serum tumor markers is necessary so as to avoid a conflict/discrepancy in the pathology report and the tumor marker level, e.g. a tumor may have a predominance of seminomatous component on microscopy but the serum tumor markers may have a marginally raised AFP, due to an unsampled yolk sac area which would warrant a regrossing of the specimen. Re-evaluation and extensive sampling are more important in pure seminoma with normal AFP. Identification of any non seminomatous germ cell tumor (NSGCT) component would radically change management.
The most common operative specimen is the radical high inguinal orchiectomy specimen wherein the testis is removed with the tunica, epididymis, and a length of spermatic cord via an inguinal approach.
| » Handling of the Gross Specimen of Orchiectomy|| |
A proper histological assessment forms a vital key to the diagnosis, further management, and clinical prognosis of the patient. The main rationale of grossing the orchiectomy specimen with respect to GCTs is in the stage I disease, where different modes of therapy are utilized for pure NSGCT and classical seminoma. A patient with stage I NSGCT, including embryonal carcinoma, with or without evidence of vascular invasion will be offered close surveillance or low-dose chemotherapy (1 cycle of BEP—bleomycin, etoposide, and cisplatin), respectively, whereas a patient with stage I seminoma may need prophylactic radiotherapy or one cycle of carboplatin to the para-aortic lymph nodes following orchiectomy., The treatment protocols postorchiectomy are, thus, guided largely by the pathology report on an orchiectomy specimen. In clinically metastatic NSGCTs and widely metastatic seminoma, platinum-based chemotherapy is the mainstay of treatment.
The pathologic classification of these primary tumors and lymph as per the 8th edition of AJCC published in 2017 is as follows: [Table 1] and [Table 2].
|Table 2: Pathologic classification of lymph nodes (pN) in primary testis tumors as per the 8th edition of American joint committee on cancer (AJCC)|
Click here to view
| » Tissue Fixation|| |
Once removed, the specimen should be either transferred immediately to the pathology department, fresh, for the removal of tissue for future studies or placed in adequate formalin to fix. The urologist should not incise the specimen as the formalin fixation causes the specimen to evert, making assessment of the relationship of the tumor to the rete or the tunica difficult and may result in tumor contamination of the resection margins. The specimen should be inked completely, generally by using one color. Use of ink is necessary on partial orchiectomy specimens where it is the only way that margin positivity can be demonstrated due to lack of an anatomic boundary.
| » Why we do what we do in testicular GCT and how we do it|| |
The essence of grossing and microscopic reporting of testicular germ cell tumors is to capture the minimum datasets encompassing the pT staging
Radical testicular specimens should be orientated by identifying the cord, the slightly more bulbous head of epididymis tapering to the tail of the epididymis, separated from the testis proper by the epididymal sinus.
- Measure the length of the spermatic cord (this confirms the adequacy of surgery as in many cases the surgeon may perform a scrotal orchiectomy with inadequate cord excision). Cut the cord cut margin from the tip of the spermatic cord and place face down in a cassette. This has to be done before incising the tumor. This ensures that the cut margin is not contaminated by the carryover from a prior incised germ cell tumor and false report of vascular invasion, which are generally very friable and have a tendency to attach to surfaces. Also, it is not uncommon to find testicular germ cell tumors in the spermatic cord
- Section base of cord and cord cut margin: This is regarded as a core data item as it is required for TNM staging but evidence on its prognostic significance in seminoma is lacking. At the time of gross dissection, a block should be taken just adjacent to the epididymis to define the hilum soft tissue, and direct invasion of tumor in this block indicates a category of pT2 [Figure 1]b.
|Figure 1: Histomorphological features: (a) Base of spermatic cord invasion (H and E, ×200). (b) Tunica albuginea not involved (H and E, ×200). (c) Tunica albuginea involved (H and E, ×200); (d) Rete testis involved in a Pagetoid manner is not to be considered as rete testis invasion (H and E, ×200).|
Click here to view
Reflect parietal tunica—note hydrocele, adhesions. Measure the testis. Comment on any tumor extension through the tunica (this would stage it as pT2). [Figure 1]b and [Figure 1]c.
- Bivalve testis through rete and epididymis.
Note: a) Tumor location (i.e., upper/lower pole, middle). This is needed as per datasets in various protocols like College of American Pathologists (CAP), Royal College of Pathologists (RCPath), etc., and carries no prognostic value.
b) Size of tumor should be assessed accurately, especially in seminomas. Several studies over the years have indicated that tumor size plays an important role in the risk stratification of testicular seminomas. One study accepted the cut-off of 4 cm as it was a mean in their series whereas another study accepted the cut-off at 7 cm., As per the International Collaboration on Cancer Reporting (ICCR) guidelines too, there was an evidentiary support to suggest that tumor size of >4 cm was independently predictive of recurrence at 5 years on multivariate analysis. Because of this variability in size cut-offs reported in the literature, the 2014 International Society of Urological Pathology (ISUP) consultation meeting agreed that a conservative approach is warranted and a relatively small size cutoff of 3 cm is used. However, it also noted that the tumor size and substaging did not affect the overall stage grouping. Also, this subclassification only applies to pure seminomas and excludes nonseminomatous or mixed germ cell tumors. A seminoma of more than 3 cm size (European association of urology (EAU) guidelines, 4 cm) with rete testis invasion may be a candidate for single agent carboplatin, as these are risk factors for recurrence in seminomas.
|Figure 2: Histomorphological features: (a) Seminoma (H and E, ×200). (b) Yolk Sac Tumor (H and E, ×200). (c) Teratoma (H and E, ×200). (d) Lymphovascular invasion in GCT (H and E, ×200)|
Click here to view
The entire testicular tumor may be blocked if it requires 10 blocks or less (tissue may be retained for special studies); 10 blocks of larger tumors may be taken, unless the tumor is greater than 10 cm, in which case 1 block may be submitted for every 1 cm of maximum tumor dimension. As alluded previously, extensive blocking is more important for pure seminomas with normal serum AFP so as not to miss any NSGCT component.
c) Color and consistency (solid/cystic); necrotic and hemorrhagic areas
In testicular GCTs, a hemorrhagic and necrotic gross area may actually represent foci of choriocarcinomatous differentiation, which is essential to demonstrate. These areas should be sampled as a sizable proportion of choriocarcinomatous element triggers an MRI investigation of whole brain for a probable metastatic disease. A minor, focal choriocarcinoma component, however, is not of any clinical relevance.
It is currently recommended that the pathologists report the approximate percentage of each component of the germ cell tumor [Figure 2]a and c]. A surveillance study of 373 men with stage 1 nonseminomatous germ cell tumors showed that the percentage of embryonal carcinoma predicted relapse. It must be noted here that a mixed seminoma and nonseminoma will be risk categorized as nonseminoma and treatment will be based on nonseminoma guidelines.
When it comes to assessment of various components of a nonseminoma on microscopy, it is imperative that percentage of embryonal component be accurately determined on microscopy, as far as possible. It should be noted here that microscopic examination and percentage calculation of components of NSGCT are biased by macroscopic sampling as cystic, necrotic, and hemorrhagic areas are more likely to represent NSGCT. Predominantly embryonal carcinoma (more than 50%) histology is another prognostic feature that is frequently associated with high rate of disease relapse in stage I nonseminomatous testicular germ cell tumor. More than 50% embryonal carcinoma would necessitate adjuvant chemotherapy with 1 cycle of BEP (bleomycin, etoposide, and cisplatin). Dunphy et al. also showed that in a study of 93 men with stage I nonseminomatous and mixed germ cell cancer undergoing surveillance following orchiectomy, 81 men had predominantly embryonal carcinoma component in their primary tumor and 35% of these developed metastases, whereas none of the patients without an embryonal carcinoma developed metastases (P = 0.05).
As alluded previously, a sizable choriocarcinomatous component and a beta-HCG level of more than 5000 would trigger a request for MRI of the brain, by the treating oncologist.
d) Tumor relationship to tunica, rete (may not be identifiable), epididymis and cord and hilum of testis:
Rete testis invasion is the direct invasion of tumor into the stroma of the rete testis and does not include pagetoid spread of germ cell neoplasia in situ (GCNIS) into the tubules of the rete. Both rete testis invasion and size are used by many clinicians to determine adjuvant chemotherapy (only in seminoma) and are part of existing European clinical guidelines. Rete testis stromal invasion is important only for seminoma and is generally not actionable in nonseminomas. In a study, 37% of European Network Uropathology members did not distinguish between pagetoid invasion, which is probably a phenomenon related to spread of intratubular germ cell neoplasia into the rete, rather than true interstitial invasion. A pagetoid spread of seminoma to rete testis epithelium should not be considered as involvement of rete testis [Figure 1]d.  Yilmaz et al. in their study identified strong correlation between the clinically determined metastatic disease and the presence of tumor invasion into rete testis and hilar soft tissues in patients with nonseminomatous germ cell tumors. ISUP and adoption by the AJCC 8th edition decided to stage soft tissue invasion as pT2. Soft tissue invasion has been defined as invasion of the adipose tissue and soft fibrous connective tissue present, beyond the boundaries of the rete testis.
e) Testicular scars, particularly in patients presenting with metastatic disease and clinically inapparent testicular primaries, may represent regressed, “burnt-out” testicular germ cell tumors. Hence, any area of scarring, calcification (burnt out GCT), or necrosis within the so called “normal testis” should be sampled adequately. This assumes more importance in which the bulk of the tumor is in the retroperitoneum with a primary regressed GCT in the testis and sampling to demonstrate these burnt-out areas may be necessary to label testis as the primary site.
f) Tumor edge and adjacent testis to facilitate assessment of lymphovascular invasion and documentation of GCNIS and atrophy and presence/absence of spermatogenesis:
Identifying foci of GCNIS near a testicular tumor may help pathologists to classify it as a germ cell tumor. Previous data also accords the fact that carcinoma in situ is nearly always present in the tissue adjacent to testicular germ cell tumors. The estimated risks of developing invasive cancer within three and five years were 40% and 50%, respectively. In several studies, the presence of vascular space invasion (usually lymphatic but possibly also capillary or venous invasion) has been correlated with a significantly elevated risk for distant metastasis. Vascular invasion is important only for nonseminoma. If vascular invasion is identified in NSGCT, then it is of paramount importance to indicate which component is seen as lymphovascular space invsion (LVSI) [Figure 2]d. A study of 102 men with stage I NSGCT demonstrated that lymphovascular invasion was the most significant risk factor predicting relapse (P = 0.0007). In another study, lymphovascular invasion was also identified as a significant poor prognostic factor, where 62% of men with lymphatic invasion developed distant metastases. This is further confirmed by Berney et al. where they demonstrated that 46% of men with vascular lymphatic invasion in their primary tumor experienced relapse. In an evaluation of 88 stage I NSGCTs, multivariate analysis showed that 23 of 88 patients with vascular invasion of the primary tumor had a high risk of relapse (61%, 95% CI 55–67%) and a linked cohort, surveillance of 105 men with stage I NSGCTs revealed that 27/105 (25.7%) men had disease relapse. All relapses in this group of men occurred within 2 years of orchiectomy and vascular invasion was identified as one of the significant predictors of relapse during surveillance
According to the 8th edition AJCC TNM staging system, discontinuous involvement of the spermatic cord soft tissue via a vascular thrombus is better regarded as a metastatic deposit (pM1). The presence of only an intravascular tumor in the spermatic cord in the absence of parenchymal invasion is considered pT2. It is of utmost importance not to interpret a knife/scalpel carry over of the tumor tissue, loosely present in the vascular channels as LVSI. The occurrence of this phenomenon is rather common in GCT as the tumors are friable and, hence, may “float” off to the vessels, in addition to the outer surface of tunica layers. Awareness of this anomaly amongst pathologists is necessary. An overinterpretation of LVSI would upstage the tumor and may induce unwarranted chemotherapy in an otherwise ineligible patient.
g) The base of cord should be sampled. Nazeer et al. state that “distinguishing between true involvement of the spermatic cord and contamination can occasionally be problematic.” Because true involvement, especially at the spermatic cord resection margin, identifies patients at a high risk for relapse, spermatic cord revision surgeries may be performed in some centres, especially in cases where the orchiectomy has been via a scrotal approach, an issue which Indian urologists face on regular basis. The problem of contamination caused by inadequate precautionary measures can be circumvented by meticulous handling and processing of the specimens.
Lymph nodal status (Primary RPLND and secondary RPLND)
In most cases of germ cell tumor, a primary retroperitoneal lymph node dissection (RPLND) is rarely done in the same setting of radical orchiectomy. More often, a RPLND is done during the follow-up patient of germ cell tumor, when there is residual mass post-chemotherapy in the retroperitoneum with normalized serum tumor markers. In such cases, the American Urological Association recommends bilateral template RPLND. This entails the removal of most of the nodes in and around the aorta and inferior venacava (IVC) (precaval, paracaval, interaortic, etc.). Unlike in lymph node dissection of specimens from other cancer sites, there is no requirement for identifying any specific prognostic nodes, such as an apical node.
The nodal yield is an important prognostic indicator and studies put the number as high as 28 lymph nodes in a RPLND to correlate with improved outcomes.
If no or less number of lymph nodes are found on dissection, the fat along the nodes can be submitted in entirety, and a note of this needs to be made. For post-chemotherapy residual masses, it is important to recognize residual viable malignancy (embryonal carcinoma, yolk sac tumor, classical seminoma, or choriocarcinoma) as it portends further chemotherapy. Necrosis and post-chemotherapy teratoma would not usually entail further therapy.
The careful microscopic analysis and reporting of retroperitoneal lymph node dissections is important for prognostic and therapeutic reasons. There are 3 main features to observe: residual, viable, nonteratomatous germ cell tumor; teratoma; and scar/necrosis. These findings may be alone or in combination. The presence of any amount of viable nonteratomatous germ cell tumor is an adverse prognostic factor and may mandate additional systemic therapy. Scars/necrosis and teratoma on its own regardless of the level of immaturity or degree of cytologic atypia have a favorable prognosis. However, if the teratoma is associated with a nongerm cell somatic malignancy, the outcome is generally adverse.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| » References|| |
Albers P, Albrecht W, Algaba F, Bokemeyer C, Cohn-Cedermark G, Fizazi K, et al
. EAU guidelines on testicular cancer. Eur Urol 2016:8-9.
Berney D, Theaker J, Verril C. The Royal College of Pathologists. Dataset for the histological reporting of testicular neoplasms, Version 3 May 2014.
Mandanas RA Saez RA, Epstein RB, Confer DL, Selby GB. Long-term results of autologous marrow transplantation for relapsed or refractory male or female germ cell tumors. Bone Marrow Transplant 1998;21:569-76.
International Germ Cell Cancer Collaborative Group. “International germ cell consensus classification: A prognostic factor-based staging system for metastatic germ cell cancers”. J Clin Oncol 1997;15:594-603.
Heinzelbecker J. Treatment of local disease in testicular cancer. In: Merseburger A., Burger M, editors. Urologic Oncology. Cham: Springer; 2018. p. 1-3.
Ahluwalia P, Gautam G. Current concepts in management of stage I NSGCT. Indian J Surg Oncol 2017;8:51-8.
Alexander EJ, White IM, Horwich A. Update on management of seminoma. Indian J Urol 2010;26:82-91.
] [Full text]
Amin MB, Edge S, Greene F, Byrd DR, Brookland RK, Washington MK, et al
. editors. AJCC Cancer Staging Manual. 8th
ed. Springer International Publishing: American Joint Commission on Cancer: AG Switzerland; 2017. p. 732-3.
Berney DM, Algaba F, Amin MB, Delahunt B, Comperat E, Epstein J, et al
. Handling and reporting of orchidectomy specimens with testicular cancer: Areas of consensus and variation among 25 experts and 225 European pathologists. Histopathology 2015;67:313-24.
Nazeer T, Ro JY, Kee KH, Ayala AG. Spermatic cord contamination in testicular cancer. Mod Pathol 1996;9:762-6.
Berney DM, Idrees MT, Tickoo SK, Yilmaz A, Comperat E, Samaratunga H, et al
. Neoplasia of the Testis, Orchidectomy, Histopathology Reporting Guide. 1st
ed.. Sydney, Australia: International Collaboration on Cancer Reporting 2017.
Boormans JL, Mayor De Castro J, Marconi L, Yaun Y, Pilar Laguna Pes M, Bokemeyer C, et al
. Testicular tumor size and rete testis invasion as prognostic factors for the risk of relapse of clinical stage I seminoma testis patients under surveillance: A systematic review by the testicular cancer guidelines panel. Eur Urol 2018;73:394-405.
Yoshida T, Kakimoto K, Takezawa K, Arai Y, Ono Y, Meguro N, et al
. Surveillance following orchidectomy for stage I testicular seminoma: Long-term outcome. Int J Urol 2009;16:756-9.
Verill C, Yilmaz A, Srigley JR, Amin MB, Comperat E, Egevad L, et al
. Reporting and staging of testicular germ cell Tumors: The International society of urological pathology (ISUP) testicular cancer consultation conference recommendations. Am J Surg Pathol 2017;41:e22-32.
Tickoo SK, Reuter VE, Amin MB, Chang SS, Humphrey PA, McKiernan J, et al
. Protocol for the Examination of Specimens From Patients With Malignant Germ Cell and Sex Cord-Stromal Tumors of the Testis. Version: Testis 184.108.40.206. June 2017.
Read G, Stenning SP, Cullen MH, Parkinson MC, Horwich A, Kaye SB, et al
. Medical research council prospective study of surveillance for stage I testicular teratoma. Medical research council testicular tumors working party. J Clin Oncol 1992;10:1762-8.
Dunphy CH, Ayala AG, Swanson DA, Ro JY, Logothetis C. Clinical stage I nonseminomatous and mixed germ cell tumors of the testis. A clinicopathologic study of 93 patients on a surveillance protocol after orchidectomy alone. Cancer 1988;62:1202-6.
Gilligan T, Lin DW, Aggarwal R, Chism D, Cost N, Derweesh IH. Testicular cancer version 2.2020. J Natl Compr Canc Netw 2019;17:1529-54.
Yilmaz A, Cheng T, Zhang J, Trpkov K. Testicular hilum and vascular invasion predict advanced clinical stage in nonseminomatous germ cell tumors. Mod Pathol 2013;26:579-86.
Von der Maase H, Rørth M, Walbom-Jørgensen S, Sørensen BL, Christophersen IS, Hald T, et al
. Carcinoma in situ
of contralateral testis in patients with testicular germ cell cancer: Study of 27 cases in 500 patients. Br Med J 1986;293:1398-401.
Stephenson A, Eggener SE, Bass EB, Chelnick DM, Daneshmand S, Feldman D, et al
. Diagnosis and treatment of early stage testicular cancer: AUA guideline. J Urol 2019;202:272-81.
Nayan M, Jewett MAS, Sweet J, Anson-Cartwright L, Bedard PL, Moore M, et al
. Lymph node yield in primary retroperitoneal lymph node dissection for nonseminoma germ cell tumors. J Urol 2015;194:386-91.
[Figure 1], [Figure 2]
[Table 1], [Table 2]