trichoepithelioma

Definition : Trichoepithelioma is a benign neoplasm that shares both clinical and histological features with basal cell carcinoma.

Images

 Trichoepithelioma

• https://twitter.com/RyanHickMD/status/720951675310047232
• https://twitter.com/mariaramir/status/714933405629198340
• https://twitter.com/JMGardnerMD/status/599210445744943104
• https://twitter.com/JMGardnerMD/status/599200913853587458
• https://twitter.com/juanbarcia/status/566378732622209024
• https://twitter.com/TheSagePatel/status/529712828757061632
• https://twitter.com/drshahinhameed/status/742390802496684033

 stroma-stroma retraction in trichoepithelioma

• https://twitter.com/RyanneMDMBA/status/673310047049408512

 small trichoepithelioma

• https://twitter.com/ASDPTweets/status/733642848189489153

 desmoplastic trichoepithelioma : cords/nests basaloid cells, sclerotic stroma, horn cysts with keratin

• https://twitter.com/mariaramir/status/714933005920378882
• https://twitter.com/JMGardnerMD/status/539428205296640000

 Trichoepithelioma CK20+ Merkel cells (usually absent in BCC)

• https://twitter.com/DermpathMGH/status/745579787800952832

 Stromal hyaline droplets in a trichoepithelioma

• https://twitter.com/RikiSotillo/status/854307415000588288

Synopsis

 multilobular basaloid tumor
 palisaded nuclei
 fibrocellular stroma
 hair follicle tumor with basaloid cells in nests surrounded by dense fibrous stroma and spindle cells
 mucin pools may be present within basaloid nests
 lack of clefting distinguishes from basal cell carcinoma

Differential diagnosis

 basal cell carcinoma (BCC)

• In Trichoepithelioma: CK20+ Merkel cells (usually absent in BCC)
• https://twitter.com/DermpathMGH/status/745579787800952832

Digital cases

 UI:910 - Trichoepithelioma

See also

 cutaenous tumors

References

 Diagnostic utility of immunohistochemistry in distinguishing trichoepithelioma and basal cell carcinoma: evaluation using tissue microarray samples. Tebcherani AJ, de Andrade HF Jr, Sotto MN. Mod Pathol. 2012 Jun 8. PMID: 22684216