Testicular epidermoid cysts, also known as keratocysts, are rare benign tumors.
Testicular epidermoid cysts account for around 1-2% of all testicular masses and typically present in mid-adulthood (2nd to 4th decades) 1,2. They are the most common type of benign testicular neoplasms 6.
The presentation can be similar to those of malignant germ cell tumors. Patients typically present with a painless and non-tender, testicular mass between 1-3 cm in diameter.
Composed of layers of keratinous debris lined with keratinizing squamous epithelium.
- non-vascular, well-marginated intratesticular mass
- may demonstrate a characteristic lamellated "onion skin" or "whorled" appearance with alternating hyperechoic and hypoechoic rings
- some lesions may show a target appearance with a halo of hypoechogenicity and a central hyperechoic region
Tend to be well demarcated.
- T1: overall signal can be variable; may show alternating rings of high and low signal
- T2: may a low-intensity rim 3; may also show alternating rings of high and low signal
- T1 C+ (Gd): typically no contrast enhancement 3
Treatment and prognosis
These lesions are benign with no malignant potential 3.
If the diagnosis of an epidermoid is suspected at the preoperative ultrasound, the lesion can be enucleated and frozen sections obtained to confirm the diagnosis. However, treatment is controversial; some authorities advocate orchiectomy, others suggest organ-sparing surgery.
- 1. Loya AG, Said JW, Grant EG. Epidermoid cyst of the testis: radiologic-pathologic correlation. Radiographics. 2004;24 Suppl 1 : S243-6. doi:10.1148/rg.24si035223 - Pubmed citation
- 2. Bennett GL, Garcia RA. Benign intratesticular dermoid cyst: sonographic findings. AJR Am J Roentgenol. 2002;179 (5): 1315-7. doi:10.2214/ajr.179.5.1791315 - Pubmed citation
- 3. Cho JH, Chang JC, Park BH et-al. Sonographic and MR imaging findings of testicular epidermoid cysts. AJR Am J Roentgenol. 2002;178 (3): 743-8. doi:10.2214/ajr.178.3.1780743 - Pubmed citation
- 4. Langer JE, Ramchandani P, Siegelman ES et-al. Epidermoid cysts of the testicle: sonographic and MR imaging features. AJR Am J Roentgenol. 1999;173 (5): 1295-9. doi:10.2214/ajr.173.5.10541108 - Pubmed citation
- 5. Dogra VS, Gottlieb RH, Rubens DJ et-al. Benign intratesticular cystic lesions: US features. Radiographics. 2001;21 Spec No : S273-81. Radiographics (full text) - Pubmed citation
- 6. Kim W, Rosen MA, Langer JE et-al. US MR imaging correlation in pathologic conditions of the scrotum. Radiographics. 2007;27 (5): 1239-53. doi:10.1148/rg.275065172 - Pubmed citation
- 7. Maizlin ZV, Belenky A, Baniel J, Gottlieb P, Sandbank J, Strauss S. Epidermoid cyst and teratoma of the testis: sonographic and histologic similarities. (2005) Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 24 (10): 1403-9; quiz 1410-1. Pubmed
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