eMedicine Specialties > Dermatology > Benign Neoplasms

Trichoepithelioma: Differential Diagnoses & Workup

Author: Victor G Prieto, MD, PhD, Director of Dermatopathology, Professor, Departments of Pathology and Dermatology, University of Texas - MD Anderson Cancer Center
Coauthor(s): Christopher R Shea, MD, Professor and Chief, Section of Dermatology, Department of Medicine, University of Chicago
Contributor Information and Disclosures

Updated: Nov 19, 2008

Differential Diagnoses

Basal Cell Carcinoma
Steatocystoma Multiplex
Colloid Milium
Syringoma
Cylindroma
Trichilemmoma
Follicular Infundibulum Tumor
Trichofolliculoma
Milia
Miliaria
Pilar Cyst

Other Problems to Be Considered

Histologic differential diagnoses (see Histologic Findings)
Basal cell carcinoma
Microcystic adnexal carcinoma
Trichoadenoma
Tumor of follicular infundibulum
Basaloid follicular hamartoma

Workup

Other Tests

  • If necessary, genetic studies may be used to detect the abnormalities in band 9p21 in trichoepithelioma (TE) patients.
  • The Medscape Genomic Medicine Resource Center may be of interest.

Procedures

  • Perform a shave or small punch biopsy to allow a histologic diagnosis.

Histologic Findings

As many as 30% of trichoepitheliomas connect with the overlying epidermis. In the upper dermis, multiple nodules are composed of uniform, basaloid cells, frequently with central, keratin-filled cysts (Media Files 2-3). Peripheral palisading is present, but artifactual clefting is uncommon. Apoptotic and mitotic figures are rarely present; central necrosis or atypical mitotic figures are not a feature. The stroma is generally fibrous, with little myxoid component. Calcification is common, typically associated with the rupture of the keratinous cysts. A distinctive feature is the papillary-mesenchymal body (fibroblastic aggregate resembling abortive follicular papillae) (see Media File 4).6

Immunohistochemical studies reveal expression of the cytokeratins associated with the outer root sheath (ie, cytokeratins 5, 6, 8, and 17) and expression of bcl-2, predominantly in the peripheral cell layer of the nests. The intervening stromal cells express CD34 (see Media File 5). Transforming growth factor beta is expressed in most trichoepitheliomas. Merkel cells can be detected in all trichoepithelioma variants. Some studies have shown that trichoepitheliomas frequently have Merkel cells (detectable with chromogranin or cytokeratin 20). Trichoepitheliomas apparently lack expression of androgen receptors, while many basal cell carcinomas are positive. CD10, a marker commonly studied in hematopathology, is consistently expressed by the stromal cells in trichoepithelioma, but it is only rarely present in those cells of basal cell carcinoma.7

Although extremely rare, some trichoepitheliomas may develop high-grade carcinomas and biphasic tumors (epithelial and sarcomatous) with aggressive behavior (including metastasis).

Trichoepithelioma variants

The desmoplastic variant, as its name indicates, is characterized by a prominent, sclerotic stroma (see Media File 6).8 It occurs in the same population as the classic type and presents as a plaque located in the same anatomical areas as the classic form. Histologically, it shows narrow strands of tumor cells, a desmoplastic stroma, and keratinous cysts (see Media File 7). Pleomorphism, palisading, or peripheral clefting are not seen. Features favoring desmoplastic trichoepithelioma include a rim of compact collagen around groups of epithelial cells, granulomas, calcification of cornified cells within cysts, absence of necrotic neoplastic cells, and only rare mitotic figures. In contrast to basal cell carcinoma, fibroblasts surrounding trichoepithelioma nests do not express the matrix metalloproteinase stromelysin-3 (ST-3).9,10

The solitary giant variant is characterized by deep involvement of the reticular dermis and subcutaneous tissue.

Differential diagnoses based on histologic study

Features of basal cell carcinoma include a combination of basaloid cells, necrotic keratinocytes, mitotic figures, palisading and peripheral clefting, and myxoid stroma. The main differential features are stroma, clefting, and absence of papillary mesenchymal bodies.

In microcystic adnexal carcinoma, small keratinous cysts are present in the upper portion; syringomalike small ducts in an infiltrative fashion are present in the deep dermis.

In trichoadenoma, similarly sized clusters of basaloid cells contain numerous keratin cysts.

In tumor of follicular infundibulum (infundibuloma), platelike growth of basaloid cells having several points of attachment to the epidermis and the follicles is observed.

In basaloid follicular hamartoma, solitary, localized, linear/nevoid, or generalized papules or plaques are observed. Thin, anastomosing cords of basaloid cells, sometimes with peripheral palisading, may be seen. Occasionally, keratin cyst formation is present.

More on Trichoepithelioma

Overview: Trichoepithelioma
Differential Diagnoses & Workup: Trichoepithelioma
Treatment & Medication: Trichoepithelioma
Follow-up: Trichoepithelioma
Multimedia: Trichoepithelioma
References
[ CLOSE WINDOW ]

References

  1. Harada H, Hashimoto K, Ko MS. The gene for multiple familial trichoepithelioma maps to chromosome 9p21. J Invest Dermatol. Jul 1996;107(1):41-3. [Medline].

  2. Bowen S, Gill M, Lee DA, Fisher G, Geronemus RG, Vazquez ME, et al. Mutations in the CYLD gene in Brooke-Spiegler syndrome, familial cylindromatosis, and multiple familial trichoepithelioma: lack of genotype-phenotype correlation. J Invest Dermatol. May 2005;124(5):919-20. [Medline].

  3. Young AL, Kellermayer R, Szigeti R, Tészás A, Azmi S, Celebi JT. CYLD mutations underlie Brooke-Spiegler, familial cylindromatosis, and multiple familial trichoepithelioma syndromes. Clin Genet. Sep 2006;70(3):246-9. [Medline].

  4. Martín de Las Mulas J, Molina AM, Millán Y, Carrasco L, Moyano R, Mozos E. Spontaneous trichoepithelioma in a laboratory mouse: gross, microscopic and immunohistochemical findings. Lab Anim. Jan 2007;41(1):136-40. [Medline].

  5. Carter JJ, Kaur MR, Hargitai B, Brown R, Slator R, Abdullah A. Congenital desmoplastic trichoepithelioma. Clin Exp Dermatol. Sep 2007;32(5):522-4. [Medline].

  6. Brooke JD, Fitzpatrick JE, Golitz LE. Papillary mesenchymal bodies: a histologic finding useful in differentiating trichoepitheliomas from basal cell carcinomas. J Am Acad Dermatol. Sep 1989;21(3 Pt 1):523-8. [Medline].

  7. Pham TT, Selim MA, Burchette JL Jr, Madden J, Turner J, Herman C. CD10 expression in trichoepithelioma and basal cell carcinoma. J Cutan Pathol. Feb 2006;33(2):123-8. [Medline].

  8. Brownstein MH, Shapiro L. Desmoplastic trichoepithelioma. Cancer. Dec 1977;40(6):2979-86. [Medline].

  9. Takei Y, Fukushiro S, Ackerman AB. Criteria for histologic differentiation of desmoplastic trichoepithelioma (sclerosing epithelial hamartoma) from morphea-like basal-cell carcinoma. Am J Dermatopathol. Jun 1985;7(3):207-21. [Medline].

  10. Thewes M, Worret WI, Engst R, Ring J. Stromelysin-3: a potent marker for histopathologic differentiation between desmoplastic trichoepithelioma and morphealike basal cell carcinoma. Am J Dermatopathol. Apr 1998;20(2):140-2. [Medline].

  11. Sajben FP, Ross EV. The use of the 1.0 mm handpiece in high energy, pulsed CO2 laser destruction of facial adnexal tumors. Dermatol Surg. Jan 1999;25(1):41-4. [Medline].

  12. Shaffelburg M, Miller R. Treatment of multiple trichoepithelioma with electrosurgery. Dermatol Surg. Oct 1998;24(10):1154-6. [Medline].

  13. Bettencourt MS, Prieto VG, Shea CR. Trichoepithelioma: a 19-year clinicopathologic re-evaluation. J Cutan Pathol. Sep 1999;26(8):398-404. [Medline].

  14. España A, García-Amigot F, Aguado L, García-Foncillas J. A novel missense mutation in the CYLD gene in a Spanish family with multiple familial trichoepithelioma. Arch Dermatol. Sep 2007;143(9):1209-10. [Medline].

  15. Hartschuh W, Schulz T. Merkel cells are integral constituents of desmoplastic trichoepithelioma: an immunohistochemical and electron microscopic study. J Cutan Pathol. Oct 1995;22(5):413-21. [Medline].

  16. Hunt SJ, Abell E. Malignant hair matrix tumor ("malignant trichoepithelioma") arising in the setting of multiple hereditary trichoepithelioma. Am J Dermatopathol. Jun 1991;13(3):275-81. [Medline].

  17. Izikson L, Bhan A, Zembowicz A. Androgen receptor expression helps to differentiate basal cell carcinoma from benign trichoblastic tumors. Am J Dermatopathol. Apr 2005;27(2):91-5. [Medline].

  18. Johnson SC, Bennett RG. Occurrence of basal cell carcinoma among multiple trichoepitheliomas. J Am Acad Dermatol. Feb 1993;28(2 Pt 2):322-6. [Medline].

  19. Kechijian P, Connors RC, Ackerman AB. Trichoepithelioma vs. basal-cell carcinoma: criteria for histologic differentiation. J Dermatol Surg. Dec 1975;1(4):22-3. [Medline].

  20. Kirchmann TT, Prieto VG, Smoller BR. CD34 staining pattern distinguishes basal cell carcinoma from trichoepithelioma. Arch Dermatol. May 1994;130(5):589-92. [Medline].

  21. Lee YS, Fong PH. Secondary localized amyloidosis in trichoepithelioma. A light microscopic and ultrastructural study. Am J Dermatopathol. Oct 1990;12(5):469-78. [Medline].

  22. Matt D, Xin H, Vortmeyer AO, Zhuang Z, Burg G, Böni R. Sporadic trichoepithelioma demonstrates deletions at 9q22.3. Arch Dermatol. May 2000;136(5):657-60. [Medline].

  23. Pariser RJ. Multiple hereditary trichoepitheliomas and basal cell carcinomas. J Cutan Pathol. Apr 1986;13(2):111-7. [Medline].

  24. Rosso R, Lucioni M, Savio T, Borroni G. Trichoblastic sarcoma: a high-grade stromal tumor arising in trichoblastoma. Am J Dermatopathol. Feb 2007;29(1):79-83. [Medline].

  25. Schulz T, Proske S, Hartschuh W, Kurzen H, Paul E, Wünsch PH. High-grade trichoblastic carcinoma arising in trichoblastoma: a rare adnexal neoplasm often showing metastatic spread. Am J Dermatopathol. Feb 2005;27(1):9-16. [Medline].

  26. Swanson PE, Fitzpatrick MM, Ritter JH, Glusac EJ, Wick MR. Immunohistologic differential diagnosis of basal cell carcinoma, squamous cell carcinoma, and trichoepithelioma in small cutaneous biopsy specimens. J Cutan Pathol. Mar 1998;25(3):153-9. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

trichoblastoma, epithelioma adenoides cysticum, trichoepithelioma papulosum multiplex, sclerosing epithelial hamartoma, Brooke tumor, TE, basal cell carcinoma

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Victor G Prieto, MD, PhD, Director of Dermatopathology, Professor, Departments of Pathology and Dermatology, University of Texas - MD Anderson Cancer Center
Victor G Prieto, MD, PhD is a member of the following medical societies: American Association for the Advancement of Science, American Medical Association, American Society for Clinical Pathologists, American Society of Dermatopathology, College of American Pathologists, European Society of Pathology, International Society of Dermatopathology, Society for Investigative Dermatology, and United States and Canadian Academy of Pathology
Disclosure: Nothing to disclose.

Coauthor(s)

Christopher R Shea, MD, Professor and Chief, Section of Dermatology, Department of Medicine, University of Chicago
Christopher R Shea, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Society of Dermatopathology, Arthur Purdy Stout Society, Association of Professors of Dermatology, Chicago Dermatological Society, Dermatology Foundation, Illinois Dermatological Society, International Society of Dermatopathology, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

Medical Editor

Evan R Farmer, MD, Professor of Dermatology, Johns Hopkins University School of Medicine, Clinical Professor of Pathology, Virginia Commonwealth University School of Medicine; Consulting Staff, Department of Dermatology, Johns Hopkins Hospital, VCU Health Services
Evan R Farmer, MD is a member of the following medical societies: American Academy of Dermatology, American Dermatological Association, American Medical Association, American Society of Dermatopathology, and International Society of Dermatology
Disclosure: Nothing to disclose.

Pharmacy Editor

Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University School of Medicine; Consulting Staff, Mountain View Dermatology, PA
Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Association of Military Dermatologists, Texas Dermatological Society, and Texas Medical Association
Disclosure: Nothing to disclose.

Managing Editor

Warren R Heymann, MD, Head, Division of Dermatology, Professor, Department of Internal Medicine, University of Medicine and Dentistry of New Jersey
Warren R Heymann, MD is a member of the following medical societies: American Academy of Dermatology, American Society of Dermatopathology, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

CME Editor

Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University
Catherine Quirk, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology
Disclosure: Nothing to disclose.

Chief Editor

William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System
William D James, MD is a member of the following medical societies: American Academy of Dermatology and Society for Investigative Dermatology
Disclosure: elsevier Royalty Other; american college of physicians Honoraria Other

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.