Penile epidermal inclusion cyst mimicking ectopic testis mass: A case report.

Epidermal inclusion cyst is a benign lesion that can originate in all parts of the human body. However, the penile location is quite rare. We reported a 24-years old man with a painless, soft, progressive-growing mass at the distal part of the penis with a history of ectopic undescended testis. Complete resection was performed, and further histopathologic study revealed an epidermal inclusion cyst of the penis. This report would like to present a rare case of a penile epidermal inclusion cyst mimicking an ectopic testis mass at our institution.

Introduction

An epidermal inclusion cyst is a benign lesion that can arise in all parts of the human body. Epidermal inclusion cyst of the skin is a fairly common benign lesion. However, occurrence in the penile region is uncommon, with only a small number of penile epidermal inclusion cysts cases reported in the literature.

Cystic lesions that are solitary, slow-growing, well demarcated accompanied by soft and smooth appearance are the characteristics of penile epidermal inclusion cystic lesions, which would not recure when removed correctly.2, 3, 4

Cryptorchidism is a ubiquitous anomaly of the male genitalia, impacting 2–4% of male infants. The etiology of cryptorchidism or ectopic testis is still largely unclear. It is unknown whether congenital testicular defects occur due to the lack of descent or imperfect testicular descent. This report presented a rare case of a penile epidermal inclusion cyst mimicking an ectopic testis mass at our institution.

Case presentation

A 24-years-old man presented at our institution with a painless progressive, growing soft mass at a slow pace, located at the distal part of the penis. The mass had been developing within the past 5 years before his initial visit, with no history of painful erections, sexual intercourse, trauma, inflammation, urinary discomfort, urinary tract infection, hematuria, or dysuria. The patient had circumcision in his childhood years.

A mass with approximately 4 cm diameter was palpated during physical examination in the distal part of the penile shaft, it was firm and immobile without any tenderness. The penile skin over the lesion was still intact and mobile, without signs of inflammation, urethral discharge, or inguinal lymphadenopathy. From palpation, the intra-scrotum testicle was only present on the left side. Hence, we suspected this mass to be an ectopic right testicle. The preoperative findings of the penile mass are shown in Fig. 1 below.

Fig. 1

(a) Penile Epidermal Cyst in the Distal Part of Penis (b) Ultrasound of the mass shows homogeneity with minimal intralesional vascularity.

Initially, the patient was diagnosed with ectopic testis. Doppler ultrasound showed an iso-echoic homogeneous mass with minimal vascularization intra-lesion, suspicious of ectopic testicle mass, as shown in Fig. 1. Complete resection was then performed under general anaesthesia, and the mass was removed entirely. The intraoperative and postoperative results are shown in Fig. 2.

Fig. 2

(a) Blue circle: tests like appearance (b) Complete resection of penile epidermal cyst (c) Postoperative result of complete resection. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

The pathological anatomy result showed penile epidermal inclusion cyst (Fig. 3). Histopathological examination revealed a greyish brown coloured encapsulated cyst with a hollow diameter of 4 cm and wall thickness of 0,5-1 cm, macroscopically. Microscopic findings revealed a cyst lined by stratified squamous epithelium with inflammatory cells found scattered on the wall adnexal components of the skin or mesenchymal structures were not found.

Fig. 3

Histopathological appearance of penile epidermal inclusion cyst with 100× magnification.

Two months after the surgery, the patient had a normal erectile function and was satisfied with the cosmetic results of the operation. He was then planned for laparoscopic surgery for the right cryptorchidism management.

Discussion

The definition of epidermal inclusion cysts is benign tumor that can arise from the hair follicles on the infundibular part. Based on the classification, penile epidermal cysts are categorized as secondary (caused by trauma or surgery) and congenital cysts. Occluded hair follicles, mechanical implantation (including injected epidermal fragments) and occluded eccrine ducts can cause secondary cysts.,

Previous trauma or surgery might have an impact on penile epidermal cysts in adults as a consequence of epidermal components being trapped inside closed space., Nearly all patients in childhood are asymptomatic; however, patients might experience painful symptoms caused trauma or infection, haematospermia, hematuria, strain during micturition, and might experience difficulties in sexual intercourse during adolescence or adulthood. In this report, the patient complained of a mass on the shaft of the penis, which had been growing in size for the last 5 years. Complaints were not accompanied by pain, fever, or other signs of inflammation.

Careful examination, ultrasonography, and computed tomography evaluations may facilitate in diagnosing penile epidermal cysts. Ultrasound does not use radiation, is easy to use, and is cost-efficient with high accuracy to diagnose penile epidermal cysts. In our case, the ultrasound revealed a homogeneous lesion with minimal intralesional vascularization, suggesting an ectopic testis.

The preferred treatment of penile epidermal cysts is surgical excision. The resection should be performed with a confirmation that there is no epithelium left to inhibit future recurrence. Surgical excision was successfully performed in our case, and the patient was planned for a postoperative follow-up to ensure no recurrence.

Conclusion

A penile epidermal cyst is a rare condition. In cases of cystic, asymptomatic, non-tender, slow-growing penile lesions, epidermal cysts should be taken into consideration. The best treatment includes a total resection.

Declaration of competing interest

None.