Testicular epidermoid cyst: A rare entity - Case report

Abstract

Introduction and importance

Epidermoid cysts (ECs) of the testicle are rare benign lesions that can mimic more serious testicular masses. Accurate diagnosis is essential for proper management, often requiring surgical intervention to confirm the nature of the mass.

Case presentation

A 21-year-old male presented with chronic pain in his right scrotum. Physical examination revealed a firm mass within the right testis. Ultrasound and MRI findings were consistent with an intratesticular EC. The patient underwent partial orchidectomy for further evaluation and treatment.

Clinical discussion

Histopathological analysis confirmed the diagnosis of an epidermoid cyst, characterized by a well-defined lesion with keratin-filled cystic spaces. The differential diagnosis for testicular masses includes both benign and malignant conditions. Imaging alone may not be sufficient to distinguish between these possibilities, making surgical exploration and histopathological examination necessary for definitive diagnosis.

Conclusion

This case highlights the importance of considering epidermoid cysts in the differential diagnosis of testicular masses in young males. Surgical intervention, such as partial orchidectomy, not only provides a definitive diagnosis but also serves as a therapeutic measure. The patient had an uneventful postoperative recovery, emphasizing the efficacy and safety of the surgical approach in such cases.

Highlights

• •We present a rare case of a testicular epidermoid cyst, emphasizing its uncommon occurrence.
• •We discusse the diagnostic challenges and highlights the characteristic imaging findings on scrotal ultrasound and MRI.
• •The case demonstrates successful surgical management through partial orchidectomy.

1. Introduction

Benign tumors of the testicle are rare, accounting for only 3 % of testicular tumors, with epidermoid cysts (ECs) being among the most common [1]. Typically diagnosed between the ages of 20 and 40 years, ECs can present with chronic scrotal pain or incidental findings on examination [2]. However, definitive diagnosis often requires imaging studies and surgical exploration. This case report describes the presentation, diagnostic evaluation, surgical management, and histopathological findings of a testicular EC, highlighting key diagnostic criteria and treatment considerations.

2. Presentation of case

A 21-year-old Moroccan male with no prior medical history presented to our department with complaints of moderate chronic pain in his right scrotum, which had persisted six months prior to presentation to us.

The patient rated his pain as 4 on the Visual Analog Scale (VAS), indicating a moderate level of discomfort. The pain was described as a dull, constant ache rather than a sharp or colicky sensation. It was localized to the right scrotum and did not radiate to other areas. The pain did not exhibit any specific aggravating factors, such as physical activity, nor did it have any relieving factors, such as rest or over-the-counter analgesics.

Physical examination revealed a firm, non-tender mass within the right testis. The mass was approximately 2 cm in diameter, smooth, and well-circumscribed. There was no associated erythema, edema, or tenderness upon palpation. The overlying scrotal skin appeared normal without any discoloration or signs of inflammation. Transillumination was negative, suggesting a solid rather than cystic nature. The left testis and epididymis were unremarkable, and there was no evidence of inguinal lymphadenopathy. The patient reported no systemic symptoms such as fever, weight loss, or night sweats.

Scrotal ultrasound demonstrated a right testicle appears normal in size, with a well-defined oval formation of regular contour. It exhibits heterogeneous echogenicity, with multilayered organization seen as alternating hypoechoic and hyperechoic layers, not showing Doppler coupling, suggestive of an intratesticular epidermoid cyst. The dimensions measure 24 × 16 mm, with intact tunica albuginea and no other abnormalities noted. The left testicle appears normal Fig. 1.

Fig. 1.

Scrotal ultrasound of the right testicle demonstrating a heterogeneous intratesticular mass with multilayered organization (yellow arrow), surrounded by normal testicular parenchyma (white arrow). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Tumor markers including alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase were within normal limits.

An MRI of the testicles completed the radiological assessment, revealing a normal-sized right testicle measuring 49 × 25 × 50 mm. It showed a nodule in the midportion, measuring 26 × 20.5 × 22 mm, with a regular contour and heterogeneous signal intensity consisting of alternating concentric rings of hypo- and hyperintensity on T1 and T2 sequences. This pattern persisted on T2 FS imaging, resembling a “target” or onion bulb appearance. The nodule exhibited restricted diffusion but did not enhance with gadolinium contrast. The left testicle appeared normal, with no iliac, inguinal, or obturator lymphadenopathy, also suggestive of an intratesticular epidermoid cyst Fig. 2.

Fig. 2.

MRI of the testicles revealing a well-defined nodule in the midportion of the right testicle (yellow arrow), with heterogeneous signal intensity and concentric rings on T1 (C) and T2 (A) sequences suggestive of an epidermoid cyst. The left testicle appears normal. Additional images show the epidermoid cyst (yellow arrow) on T1 FS fast signal (B), T2 FS (D), coronal T2 (E), diffusion-weighted imaging (F), and apparent diffusion coefficient (ADC) mapping (G). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

A surgical exploration was planned, involving an elective incision through a high inguinal approach, non-traumatic clamping of the spermatic cord, and exteriorization of the testicle. Partial orchidectomy was performed. Upon opening the tunica albuginea, a well-encapsulated, firm cystic mass originating from the middle of the testis was revealed. The cystic lesion was excised en bloc with a margin of normal testicular tissue Fig. 3.

Fig. 3.

Intraoperative photograph showing the excision of the epidermoid cyst (EC) from the middle of the right testis. The cystic lesion is well-encapsulated and firm (yellow arrow), originating from the testicular parenchyma (with arrow) and surrounded by the albuginea (black arrow). Picture B shows the excised epidermoid cyst. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

We performed an intraoperative frozen section examination, confirming the benign nature of the lesion. The histopathological final examination revealed a specimen measuring 2 × 2 cm, with cross-sections showing a cystic formation delimited by a stratified squamous epithelial lining without atypia. The content of the cyst consisted of layers of keratin obliterating almost the entire cystic space. No signs of epithelial proliferation were observed, confirming the final diagnosis of epidermoid cyst of the testicle, with no histological evidence of malignancy.

The patient had an uneventful postoperative recovery and was discharged on the first postoperative day.

At the 6-month follow-up, the patient was asymptomatic with no recurrence of pain. Physical examination revealed no palpable masses, and the surgical scar had healed well. A scrotal ultrasound showed no residual or recurrent lesions. The patient remained in good health.

In light of the patient's young age and potential fertility concerns, pre-operative and post-operative seminal fluid analyses were conducted to evaluate any potential impacts of the surgery on spermatogenic function. Prior to the surgery, the patient's seminal fluid analysis showed the following parameters: sperm concentration of 50 million/mL, motility of 60 %, and normal morphology of 15 %. Six months post-operatively, a follow-up seminal fluid analysis revealed a sperm concentration of 48 million/mL, motility of 58 %, and normal morphology of 16 %. These results were consistent with pre-operative values and indicated no significant negative effects on sperm concentration or motility. This suggests that the testicular-preserving surgery effectively maintained the patient's fertility.

3. Discussion

Benign tumors of the testicle are rare, accounting for only 3 % of testicular tumors [1].

Epidermoid cysts (ECs) are among the most common benign testicular tumors, typically diagnosed between the ages of 20 and 40 years [2]. Epidermoid cysts represent approximately 1–2 % of all testicular tumors. They are non-germ cell tumors and are considered benign with no malignant potential. While their exact etiology remains unclear, they are thought to arise from aberrant squamous epithelial cells within the testicle [3].

In 80 % of cases, they are asymptomatic and are often discovered incidentally through self-palpation or during routine clinical examination. However, they can occasionally present with scrotal heaviness, pain, or testicular enlargement. Typically, ECs are solitary, firm, painless masses with a smooth surface, although clinical examination alone cannot provide a definitive diagnosis [3]. Bilateral or unilateral multiple ECs are exceptionally rare [2]. ECs are considered uni-tissular or simplified teratomas.

PRICE in 1969 defined five anatomopathological criteria that must be met for a diagnosis of isolated EC. The EC must be located within the testicular parenchyma and surrounded by a wall composed of fibrous tissue, which is completely or partially lined with squamous epithelium. Its lumen should contain keratin lamellae or amorphous material, and there should be an absence of teratomatous elements or cutaneous annexes. Additionally, there should be no presence of a hyaline scar in the wall of the EC or in the adjacent testicular parenchyma [4]. Adherence to these criteria is essential to avoid overlooking associated teratomas or germ cell tumors. Macroscopically, ECs appear as whitish nodules that can be easily divided, with a cross-section revealing a white, gritty substance corresponding to rolled keratin concretion. Tumor markers (alpha-fetoprotein and beta-human chorionic gonadotropin) are always normal in cases of isolated EC [5].

Ultrasound typically shows a characteristic ‘onion skin’ or ‘target’ appearance, which is specific for testicular epidermoid cysts. This pattern differentiates between the center and periphery of the cyst, revealing a well-defined intra-testicular mass with a hypoechoic to echogenic wall. Focal calcifications may cause hyperechoic areas within the wall. The center of the cyst is heterogeneous, displaying hyper- or hypoechoic areas due to the density of the keratin lamellae. Other ultrasound manifestations include cystic mass type, cystic solid mass type, and coarse calcification type, which can further aid in diagnosis.

MRI can further refine the diagnosis, demonstrating hypointensity of the cyst capsule on T1 and T2-weighted imaging, as well as hypointensity of the cyst center on T1 and T2-weighted imaging. Between these zones, there is hyperintensity on T1 and T2-weighted imaging corresponding to isolated and degenerated epithelial cells (rich in water and fat). There is no signal enhancement after contrast agent injection [5].

Treatment remains primarily surgical. Partial orchidectomy, via an inguinal approach with cord clamping and frozen section examination, appears to be the standard, allowing for gonad preservation in young patients [3]. Total orchidectomy is possible in cases of very large cysts or diagnostic uncertainty [1].

There have been no reported metastases or local recurrence after total or partial orchidectomy for isolated pure epidermoid cysts of the testicle, with a follow-up period of 40 years [4].

In terms of prognosis, the potential impact of testicular surgery on spermatogenic function should be carefully considered. Testicular-sparing surgery, which aims to preserve fertility, has been shown to maintain normal spermatogenic function in approximately 85–90 % of cases where the surrounding healthy tissue is preserved. However, surgical intervention on the testis, particularly in cases involving large cysts or coarse calcifications, can lead to a decline in spermatogenesis due to disruption of the blood-testis barrier or thermal damage caused by electrocautery [7].

A study by Paffenholz et al. found that among patients undergoing testicular surgery for benign lesions, around 10–15 % experienced reduced sperm count or quality in follow-up assessments. In cases of large epidermoid cysts exceeding 2 cm in diameter, the risk of impaired spermatogenic function was significantly higher [7]. Further research is required to determine long-term fertility outcomes, especially in patients who undergo surgery for larger or more complex cystic lesions. Additionally, factors such as the patient's pre-operative fertility status and the extent of the surgical procedure are crucial in predicting post-operative outcomes.

4. Conclusion

Testicular epidermoid cysts are rare benign lesions that can present with chronic scrotal pain or incidental findings on examination. Surgical exploration via partial orchidectomy remains the gold standard for diagnosis and treatment, with excellent prognosis and low rates of recurrence. Long-term follow-up is essential to monitor for potential complications or recurrence, although metastases or local recurrence are exceptionally rare. This case underscores the importance of considering ECs in the differential diagnosis of testicular masses and the efficacy of surgical intervention in achieving favorable outcomes.

Consent

The patient provided informed consent after receiving detailed information regarding the study and its implications.

Methods

This case report has been reported in line with the SCARE criteria [6].

Ethical approval

This case report is exempt from ethical approval according to the guidelines of the Institutional Review Board (IRB) of Ibn Sina University Hospital. According to our institution's policies, case reports and studies that do not involve clinical trials or interventions are not subject to formal ethical review. Informed consent was obtained from the patient for the publication of this report. As formal ethical approval was not required, no reference number is applicable.

Funding

This research and the publication expenses were solely supported by the author, and no specific grant was received from any public, commercial, or non-profit sectors.

Author contribution

Salim Lachkar: Study concept, writing the paper.

Anouar El Ghazaly: Data collection.

Mohammed Mrabti: Data collection, critical revision of the manuscript.

Nabil Louardi: Study supervision, manuscript revision.

Mohammed Alami: Critical revision of the manuscript.

Ahmed Ameur: Study supervision, manuscript revision.

Guarantor

LACHKAR Salim.

Research registration number

Not applicable to this case report.

Conflict of interest statement

None.