Testis & paratestis
Germ cell tumors
Teratoma-epidermoid cyst
Last author update: 1 December 2012
Last staff update: 4 August 2023
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PubMed Search: Teratoma-epidermoid cyst [title] testis
Table of Contents
Definition / general | Case reports | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Molecular / cytogenetics description | Molecular / cytogenetics images | Differential diagnosisCite this page: Gordetsky J, Williamson S. Teratoma-epidermoid cyst. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisepidermoidcyst.html. Accessed September 21st, 2023.
Definition / general
- Rare benign cyst, < 1% of testicular tumors
- Usually ages 10 - 39
- Unclear if neoplastic - occasionally has allelic losses, favoring neoplasia (Arch Pathol Lab Med 2003;127:858)
- Pilomatricoma / pilomatrixoma (histologic changes including shadow cells, which resemble cutaneous piiomatrixoma), is considered a subtype (Am J Surg Pathol 2001;25:788, Arch Pathol Lab Med 1995;119:96)
Case reports
- 21 and 27 year old men (Cesk Patol 2005;41:102)
Gross description
- Intraparenchymal lesion, usually adjacent to tunica albuginea, mean 2 cm, contains white grumous keratin debris
Microscopic (histologic) description
- Cyst with keratinized squamous epithelial lining containing a granular cell layer, cyst filled with laminated keratin
- Cyst rupture may cause granulomatous reaction
- No adnexal structures, no other tissue types
- Pilomatrixoma-like variant:
- Adjacent testis does not show intratubular germ cell neoplasia, unclassified type (IGCNU)
- Eosinophilic islands of "shadow" squamous epithelium with focal, peripheral calcification and ossification
- The ghost-like cells are similar to the shadow cells of cutaneous pilomatrixoma (Am J Surg Pathol 2001;25:788)
Microscopic (histologic) images
Contributed by Debra L. Zynger, M.D.
Testicular epidermoid cyst
Cyst wall with adjacent normal seminiferous tubule
Lamellar keratin within the cyst
Stratified squamous epithelium with adjacent keratin
Molecular / cytogenetics description
- Isochromosome 12p and other overrepresentation of 12p are present in usual teratoma but not in epidermoid cyst (Clin Cancer Res 2006;12:5668)
Molecular / cytogenetics images
Images hosted on other servers:
Normal FISH for 12p
Differential diagnosis
- Teratoma: usually postpubertal testis, IGCNU present, often atypia in teratomatous elements
