Squamous Cell Carcinoma Arising in an Epidermal Inclusion Cyst

Authors

Suzanne Alkul
Christopher N Nguyen
Nisha S Ramani
Mahmud Alkul
Ida Orengo
Ikue Shimizu
Bhuvaneswari Krishnan

Publication Date

1-1-2022

Journal

Baylor University Medical Center Proceedings

DOI

10.1080/08998280.2022.2077600

PMID

35991710

PMCID

PMC9373787

PubMedCentral® Posted Date

5-23-2022

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Diagnostic errors, epidermal cyst, neoplastic cell transformation, squamous cell carcinoma

Abstract

Squamous cell carcinoma (SCC) arising from an epidermal inclusion cyst (EIC) is uncommon. We present a case of a 70-year-old man with a scalp nodule with persistent discharge that was resected based on the clinical impression of an EIC. Histopathologic exam showed an infundibular EIC with an epidermal type of squamous epithelium; however, some of the cyst lining and lumen was replaced by squamous proliferation with malignant features. There are 56 cases of SCC arising in EICs reported in the English literature. Though suspected EICs are commonly benign, a thorough pathologic evaluation is required to rule out malignancy.