EPIDERMOID CYST OF TESTIS: REPORT OF FIVE CASES AND REVIEW OF THE LITERATURE

Epidermoid cyst and teratoma of the testis: sonographic and histologic similarities

OBJECTIVE

The classic sonographic description of an epidermoid cyst is a mass with a target or onion ring appearance of alternating rings of hyperechogenicity and hypoechogenicity. This study presents a pathologic-sonographic assessment of classic and nonclassic appearances of an epidermoid cyst of the testis and reports the possible similarity between a classic epidermoid cyst and a teratoma on sonography.

METHODS

We reviewed the sonographic and histologic features of 8 testicular tumors that either had a classic onion ring pattern or were found at pathologic examination to be epidermoid cysts but did not have the classic sonographic pattern.

RESULTS

Three epidermoid cysts had a typical onion ring appearance. Histologic sections of these tumors revealed a squamous epithelial layer lining the cyst and multiple concentric laminated layers of keratin. Two tumors did not have a typical sonographic appearance of epidermoid cysts but were found to be epidermoid cysts at pathologic examination. One was homogeneously hypoechoic, and the other had irregular cystic and solid components, but neither had a target or onion ring appearance. Histologically, both of these tumors consisted of cystic cavities lined by squamous epithelium and contained desquamated keratinized epithelium. Notably, 3 other tumors pathologically diagnosed as teratomas had a sonographic appearance of classic epidermoid cysts. These tumors contained layers of keratin, but the cyst was lined by both squamous cells (ectodermal origin) and cylindrical epithelium (endodermal origin), thereby precluding the diagnosis of epidermoid cysts.

CONCLUSIONS

There is considerable overlapping of the sonographic appearances of teratomas and epidermoid cysts of the testis. Although the onion ring appearance of an intratesticular tumor is suggestive of an epidermoid cyst, this appearance may also be found in cases of a teratoma. Whereas the former condition can be treated by local enucleation, the latter requires radical orchiectomy.

Epidermoid cyst in a solitary testis: A case for non-surgical management

This is a case report of a 71-year-old man who presented with an incidental finding of a mass in a solitary right testis. A scrotal ultrasound scan showed the typical features of a testicular epidermoid cyst. Tumour markers were not elevated and the patient was managed non-operatively. On reviewing the literature, we found no previous report on the non-operative management of testicular epidermoid cysts

Ultrasound of testicular epidermoid cysts

The ultrasound findings of focal intratesticular lesions may sometimes be characteristic of benign pathology, which accounts for approximately 5% of all testicular tumours. Three cases of epidermoid cysts of the testis are presented along with a review of the literature. Recognition of the typical ultrasound appearances of this entity in a clinical situation of painless testicular swelling in the absence of a history of trauma and signs of inflammation can make testis-sparing surgery feasible.

Testicular epidermoid cysts in prepubertal children: case report and review of the world literature

Epidermoid cysts of the testes are rare, benign lesions that account for approximately 1% of all testicular tumors. They present most often between the second and fourth decade of life, and have been reported in prepubertal children rarely. The authors report the clinical and sonographic findings in a 4 1/2-year-old child with a testicular epidermoid cyst, and they analyze the 22 prepubertal cases found in the world literature. As described below, the clinical and sonographic features of this tumor are not specific for an epidermoid cyst and do not preclude a teratomatous or malignant neoplasm. This case adds to the varied sonographic appearance of prepubertal testicular epidermoid cysts. The lack of either unique clinical or sonographic features would suggest that extreme caution be used if local excision is considered for a patient with presumed epidermoid cyst of the testicle.

Epidermoid cyst of the testis: a review of clinical and histogenetic considerations

OBJECTIVE

To review the records of patients with epidermoid cysts and those with germ cell tumours to determine the most appropriate method of treatment.

PATIENTS AND METHODS

The records of the patients treated for epidermoid cysts and testicular germ-cell tumours in a period covering 22 years were analysed retrospectively. Nine specimens with an epidermoid cyst were examined by immunohistology for the presence of testicular intraepithelial neoplasia (TIN) (or carcinoma in situ of the testis).

RESULTS

Ten patients with a simple epidermoid cyst and 481 patients with testicular germ-cell tumour were treated during the observation period. The relative incidence of epidermoid cysts in relation to the number of patients with testicular germ-cell tumours was 2.1% (95% confidence interval 0.8-3.35%). The mean age of the 10 patients with an epidermoid cyst was 24.1 years. The right testis was affected in seven patients and the left in three. Six of these patients received conservative surgery with excellent cosmetic results. No relapse had occurred after a median observation period of 30 months. Immunohistological staining for placental alkaline phosphatase disclosed the absence of TIN in the parenchyma surrounding the cysts.

CONCLUSION

The absence of TIN calls into question the common assumption that an epidermoid cyst constitutes a monodermal teratoma. Two distinct entities of epidermoid cyst are proposed--one occurring in conjunction with a teratoma or a germ cell tumour (a 'complex' or 'mixed' epidermoid cyst) and the other a 'simple' epidermoid cyst without TIN in the adjacent tissue and thus representing a benign neoplasm that is not a teratoma. The absence of TIN near a simple epidermoid cyst justifies testis-sparing surgery.

Epidermoid cysts of testes and role of sonography

Four patients with histologically proved epidermoid cysts of the testicle were managed with radical orchiectomy. High-resolution testicular sonography demonstrated similar findings in all cases, but these findings were not specific and did not preclude other malignant or teratomatous lesions. The lack of both unique clinical features and specific sonographic findings would suggest that extreme caution must be used if wedge resection or enucleation is contemplated for a patient with presumed epidermoid cyst.

Epidermoid cyst of the testicle in children

Epidermoid cyst of the testicle is rare in children and only four previous cases have been reported. We add two cases and discuss their presentation and management. Both children presented with solid testicular masses, one of which was asymptomatic and the other was painful. Physical examination and ultrasound could not differentiate between a benign and malignant process. One child underwent radical orchiectomy and one child underwent local excision alone. Both are free of disease at follow-up.

Sonographic characteristics of epidermoid cyst of testicle

The ultrasonographic characteristics of an epidermoid cyst of the testicle are presented. Since these findings are similar to other published case reports, preoperative sonographic diagnosis of this lesion may be possible.

Epidermoid cyst of testis: a case for orchiectomy

Epidermoid cyst of the testis is a benign lesion without report of metastasis. It cannot be differentiated reliably from the far more common malignant testicular mass on a clinical basis. Simple excision of the cyst, even with concurrent biopsy of the apparently normal surrounding parenchyma, does not exclude the possibility of a remote scar or focus of viable tumor. The existence of a concurrent malignant lesion along with an epidermoid cyst may be more than coincidental. For such an undetected associated lesion, appropriate highly successful adjunctive therapy is delayed if excision of the epidermoid cyst alone is performed. Consequently, inguinal orchiectomy should be the treatment of choice for epidermoid cyst of the testis with the subsequent burden of proof placed on the pathologist to exclude associated lesions that may alter therapy.

Epidermoid cyst of the testis: a critical analysis

Our experience with 163 patients (11 from our institution) with simple epidermoid cyst of the testis was analysed. The lesion is nearly as common as interstitial cell tumour of the testis. In its simple form it is a benign lesion that usually appears as a solitary, asymptomatic, testicular, 2-cm mass in non-black young men (usually 20 to 40 years of age). It has been suspected on circumstantial clinical evidence in a few patients (17.5%) who have been successfully treated by simple enucleation. In the majority, however, fear of looking for a zebra in a herd of horses or not thinking of zebras at all has led to radical orchiectomy. None of the 80 patients followed up for a maximum of 37 years has suffered any ill effects.

Epidermoid cysts of the testis: role of conservative surgery

Epidermoid cysts of the testis are rare benign lesions that clinically resemble intratesticular neoplasms. Preoperative testicular ultrasound and an operative frozen section biopsy may help to establish the diagnosis without resorting to orchiectomy. In such selected cases local excision alone should be considered adequate without violating accepted surgical principles.

Epidermoid cysts of the testis: a report of three cases and an analysis of 141 cases from the world literature

Epidermoid cysts of the testis are rare and represent about 1% of all testicular tumors. An analysis of 141 cases reported to date in the world literature, including the cases reported here, indicates that 50% of the lesions occur in the third decade and 86% between the second and fourth decade. The most common presentations are painless enlargement of the testis (41%) for an average period of 2.25 years or incidental detection during routine physical examination (33%). Clinically, a discrete testicular nodule can be palpated in the majority of the cases (76%). Pathologic findings are those of a squamous lined cyst containing keratin with absence of appendages or other elements. It is believed that, despite the benign nature of the lesion, they should be treated by orchiectomy so that a thorough pathologic examination can be done to establish a confident diagnosis. While some controversy exists about their source of origin, all the evidence, including the age, more common occurrence among whites, and the rare reported cases arising in cryptorchid testis points to a germ cell origin for these lesions. The epidermoid cyst should thus be recognized as another subtype in the category of germ cell tumors of the testis and perhaps the ovary.

Epidermoid cysts of testis

Six cases of epidermoid cyst of the testis are presented. Conservative surgical treatment of this condition is discussed.