Urology Annals
About UA | Search | Ahead of print | Current Issue | Archives | Instructions | Online submissionLogin 
Urology Annals
  Editorial Board | Subscribe | Advertise | Contact
Users Online: 1051   Home Print this page  Email this page Small font size Default font size Increase font size


 
Table of Contents
CASE REPORT
Year : 2021  |  Volume : 13  |  Issue : 3  |  Page : 308-311  

Testicular fibroma: A case report and literature review


1 Department of Pathology, King Fahad Medical City, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
2 Department of Urology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
3 Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre; College of Medicine, Alfaisal University, Riyadh, Saudi Arabia

Date of Submission24-Jul-2020
Date of Acceptance24-Jan-2021
Date of Web Publication23-Jun-2021

Correspondence Address:
Dr. Turki Omar Al-Hussain
Department of Pathology and Laboratory Medicine (MBC 10), King Faisal Specialist Hospital and Research Center, P.O Box 3354, Riyadh 11211
Saudi Arabia
Login to access the Email id


DOI: 10.4103/UA.UA_119_20

Rights and Permissions
   Abstract 


Sex cord-stromal tumors are the second most common testicular tumors after germ cell tumors. They account for about 2%–5% of adult testicular tumors. Most of these tumors are benign. The most common sex cord-stromal tumor is Leydig cell tumor. In contrast, testicular fibroma is a very rare type of sex cord-stromal tumors. Histologically, testicular fibromas resemble their ovarian counterparts; however, they are much less common than ovarian fibromas. To the best of our knowledge, <50 cases of testicular fibromas are reported in the English literature. Herein, we report a rare case of testicular fibroma with acellular collagen plaque in a 51-year-old male presenting as a painless testicular mass.

Keywords: Fibroma, sex cord-stromal, testis, thecoma, tunica albuginea


How to cite this article:
Algarni AM, Junejo NN, Alkhateeb SS, Al-Hussain TO. Testicular fibroma: A case report and literature review. Urol Ann 2021;13:308-11

How to cite this URL:
Algarni AM, Junejo NN, Alkhateeb SS, Al-Hussain TO. Testicular fibroma: A case report and literature review. Urol Ann [serial online] 2021 [cited 2021 Aug 3];13:308-11. Available from: https://www.urologyannals.com/text.asp?2021/13/3/308/319082




   Introduction Top


Testicular sex cord-stromal tumors are divided into pure, mixed, and unclassified tumors according to the 2016 World Health Organization (WHO) classification of tumors of the testis.[1] The pure tumors include Leydig cell tumor, Sertoli cell tumor, granulosa cell tumor, and tumors in the fibroma-thecoma group. Fibroma and thecoma are closely related tumors, and hence, they are considered under one category in the 2016 WHO classification of tumors of the testis. Testicular fibroma is a rare sex cord-stromal neoplasm derived from either the gonadal stroma or the tunica albuginea.


   Case Report Top


This is a 51-year-old-male smoker with multiple comorbidities including obesity, type 2 diabetes mellitus, hypertension, ankylosing spondylitis, and chronic interstitial nephritis. He had a past surgical history of bilateral total hip replacement. He was referred to urology with a 2-year history of small painless testicular mass, which recently increased in size. No history of testicular trauma or sign and symptoms of epididymo-orchitis. Ultrasound of scrotum showed a solid heterogeneous mass in the upper pole of the left testis measuring 2.7 cm [Figure 1]a and [Figure 1]b. Tumor markers were performed including alpha fetoprotein, beta human chorionic gonadotropin, and lactic dehydrogenase, and all were within the normal limits. Left inguinal radical orchiectomy was performed. Gross examination showed a well-circumscribed intratesticular firm, white, and homogenous mass measuring 3.0 cm × 2.5 cm × 2.5 cm [Figure 2]. There was no attachment to the tunica albuginea. Necrosis and hemorrhage were absent. Microscopic examination showed an unencapsulated proliferation of spindle cells separated by thick collagen bundles with entrapped seminiferous tubules at the periphery [Figure 3]a. The neoplastic cells were arranged in the fascicular growth pattern with scant cytoplasm and elongated nuclei [Figure 3]b. Acellular collagen plaques were identified [Figure 3]c and [Figure 3]d. Mitotic figures were up to 5 per 10 high-power fields (HPFs). There was no evidence of increased cellularity and nuclear atypia or necrosis. Entrapped seminiferous tubules are noted at the periphery of the tumor. Immunohistochemical stains were performed on a Ventana Benchmark Ultra autostainer (Ventana Medical System, Tucson, AZ). The tumor cells were positive for calretinin (Ventana; prediluted) and inhibin (Ventana; prediluted) [Figure 4]. The tumor cells were negative for cytokeratin AE3/AE1 (Ventana; prediluted), β-Catenin (Ventana; prediluted), S100 protein (Ventana; prediluted), Melan-A (Ventana; prediluted), CD34 (Ventana; prediluted), STAT-6 (Acris GmbH; 1:50), SMA (Ventana; prediluted), and Desmin (Ventana; prediluted). The diagnosis was testicular fibroma. The patient is under regular follow-up. A computed tomography scan of the abdomen and pelvis was performed after 6 months of the surgery, and there was no evidence of recurrence or metastasis.
Figure 1: (a and b) Scrotal ultrasonography showing solid heterogeneous mass

Click here to view
Figure 2: Gross photograph of testis showing an intratesticular well-cirumscribed gray white tumor

Click here to view
Figure 3: (a) Section from the tumor showing spindle cell proliferation with collagen bundles and entrapped seminiferous tubules at the periphery (Hematoxylin and eosin stain) (b) High power of the tumor with fascicular growth pattern and elongated nuclei. (Hematoxylin and eosin stain) (c and d) Acellular collagen plaques. (Hematoxylin and eosin stain)

Click here to view
Figure 4: Calretinin immunohistochemical stain with strong positivity

Click here to view



   Discussion Top


Testicular fibroma is a rare sex cord-stromal neoplasm. In 1997, Jones et al. proposed the term fibroma of gonadal stromal origin for neoplasms that arise within the testicular parenchyma and simulate ovarian fibromas.[2] Fibroma and thecoma are closely related tumors, so the term fibrothecoma is commonly used to cover both entities.[1],[3] The terms fibroma of gonadal stromal origin, fibroma, and fibrothecoma are generally used to describe same entity.[1] Only few cases of testicular fibroma have been published in the literature.[2],[3],[4],[5],[6] The largest case series was reported in 2013 by Zhang et al. were they studied 16 cases of testicular fibrothecoma.[3] Testicular fibroma is usually present as a slowly growing painless unilateral testicular mass in most of patients as in our case. They are present at a wide range of age from 16 to 69 years with a mean of 44 years.[3] Macroscopically, testicular fibromas are well circumscribed tumors with a firm white-tan cut surface and have variable size from 0.5 to 7.6 cm in maximum dimension.[3] They often abut the tunica albuginea; however, some are centrally located within the testicular parenchyma.[1],[2],[3] Microscopically, fibromas are unencapsulated cellular spindle cell tumors that composed of fibroblasts with fascicular or storiform growth patterns associated with intervening collagen. Acellular collagen plaques are rarely seen as in the current case.[2] The cells have elongated cytologically bland nuclei; however, focal epithelioid component may occur.[3] Most cases have up to 5 mitoses/10 HPFs, and only rare cases may have up to 10 mitoses/10 HPFs.[2],[3] Although some tumors may show worrisome features such as hypercellularity and increased mitotic activity, they still have benign behavior. Zhang et al. reported two cases with 9–10 mitoses/10 HPFs, one died of other causes 5 years and 8 months and the other had no evidence of disease at 4 years and 10 months.[3] Immunohistochemically, fibromas are often positive for inhibin and calretinin with variable expression of Melan-A, SMA, S100, CD34, BCL2, cytokeratin, S100 protein, and EMA.[1],[2],[3]

The differential diagnosis of testicular fibroma includes Sertoli cell tumor, adult granulosa cell tumor, myoid gonadal stromal tumor, unclassified sex cord-stromal tumor, and solitary fibrous tumor. Sertoli cell tumor may have ovoid cells that resemble fibroma; however, tubular differentiation is usually present at least focally. Immunohistochemistry is also helpful for the diagnosis of Sertoli cell tumor where majority of these tumors show nuclear expression of β-catenin.[7] Adult granulosa cell tumor of the testis is extremely rare. It has similar features of ovarian counterpart with different patterns of growth including diffuse, insular, spindled, trabecular, and pseudopapillary. Call-Exner bodies are helpful clue to the diagnosis as well as nuclear grooves of tumor cells.[8] Myoid gonadal stromal tumor has the features of smooth muscle and gonadal stroma which can resemble testicular fibroma. It is composed of spindle cells with elongated nuclei and occasional nuclear grooves arranged in fascicles with admixed variably ectatic blood vessels.[1],[9] However, the tumor cells are diffusely positive for S100 protein, smooth muscle actin, FOXL2, and steroidogenic factor 1 and negative for calretinin and h-Caldesmon. Inhibin can be focally positivity.[9] Fibrous stroma of unclassified sex cord stromal tumor may have similarity with testicular fibroma; however, the presence of other component of epithelial cells of sex cord type is a helpful feature of this tumor which can be highlighted by reticulum stain.[1],[3]

Solitary fibrous tumor is another rare differential diagnosis that may have a similar morphology to testicular fibroma; however, it is usually present as paratesticular mass. A characteristic patternless pattern of growth with “stage horn” appearance of blood vessels as well as positivity for CD34 and STAT6 and lack of expression of inhibin and caretinin are typical features of solitary fibrous tumor.[10] Finally, surgical excision seems to be a curative treatment of testicular fibroma.


   Conclusion Top


Testicular fibroma is a rare benign sex cord-stromal tumor with characteristic morphological features and immunohistochemical staining profile. Despite some worrisome features that present in few testicular fibromas, they behave in a benign fashion.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Oliva E, Young RH, Ulbright TM. Sex cord-stromal tumours. In: Moch H, Humphrey PA, Ulbright TM, Reuter VE, editors. WHO Classification of Tumours of the Urinary System and Male Genital Organs. 4th ed. Lyon, France: International Agency for Research on Cancer; 2016. p. 227-35.  Back to cited text no. 1
    
2.
Jones MA, Young RH, Scully RE. Benign fibromatous tumors of the testis and paratesticular region: A report of 9 cases with a proposed classification of fibromatous tumors and tumor-like lesions. Am J Surg Pathol 1997;21:296-305.  Back to cited text no. 2
    
3.
Zhang M, Kao CS, Ulbright TM, Epstein JI. Testicular fibrothecoma: A morphologic and immunohistochemical study of 16 cases. Am J Surg Pathol 2013;37:1208-14.  Back to cited text no. 3
    
4.
Jabbour MN, Zaatari GS, Tfayli AH, Abdul-Karim FW. Testicular fibroma. J Urol 2012;188:1944-5.  Back to cited text no. 4
    
5.
Sourial MW, Sabbagh R, Doueik A, Ponsot Y. A 17 year old male with a testicular fibrothecoma: A case report. Diagn Pathol 2013;8:152.  Back to cited text no. 5
    
6.
Deveci MS, Deveci G, Ongürü O, Kilciler M, Celasun B. Testicular (gonadal stromal) fibroma: Case report and review of the literature. Pathol Int 2002;52:326-30.  Back to cited text no. 6
    
7.
Perrone F, Bertolotti A, Montemurro G, Paolini B, Pierotti MA, Colecchia M. Frequent mutation and nuclear localization of β-catenin in sertoli cell tumors of the testis. Am J Surg Pathol 2014;38:66-71.  Back to cited text no. 7
    
8.
Cornejo KM, Young RH. Adult granulosa cell tumors of the testis: A report of 32 cases. Am J Surg Pathol 2014;38:1242-50.  Back to cited text no. 8
    
9.
Kao CS, Ulbright TM. Myoid gonadal stromal tumor: A clinicopathologic study of three cases of a distinctive testicular tumor. Am J Clin Pathol 2014;142:675-82.  Back to cited text no. 9
    
10.
Doyle LA, Vivero M, Fletcher CD, Mertens F, Hornick JL. Nuclear expression of STAT6 distinguishes solitary fibrous tumor from histologic mimics. Mod Pathol 2014;27:390-5.  Back to cited text no. 10
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
   Case Report
   Discussion
   Conclusion
    References
    Article Figures

 Article Access Statistics
    Viewed230    
    Printed6    
    Emailed0    
    PDF Downloaded20    
    Comments [Add]    

Recommend this journal