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Testis & paratestis

Nonneoplastic lesions

Epidermoid cyst

Authors: Jennifer B. Gordetsky, M.D., Sean R. Williamson, M.D.

Last author update: 1 December 2012

Last staff update: 19 March 2024

Copyright: 2002-2024, PathologyOutlines.com, Inc.

PubMed Search: Teratoma-epidermoid cyst testis

Table of Contents

Cite this page: Gordetsky J, Williamson S. Epidermoid cyst. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisepidermoidcyst.html. Accessed December 22nd, 2024.

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. and @ThatGlassTho on Twitter