Trichoepithelioma Workup

  • Author: Victor G Prieto, MD, PhD; Chief Editor: Dirk M Elston, MD   more...
 
Updated: Jan 29, 2010
 

Other Tests

If necessary, genetic studies may be used to detect the abnormalities in band 9p21 in trichoepithelioma patients.

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Procedures

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

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Histologic Findings

As many as 30% of trichoepitheliomas connect with the overlying epidermis, but in general they are circumscribed, dermal nodules, as shown in the image below.

Image of glass slide showing a nodular, very well-Image of glass slide showing a nodular, very well-circumscribed proliferation.

In the upper dermis, multiple nodules are composed of uniform, basaloid cells, frequently with central, keratin-filled cysts, as in the images below.

Well-circumscribed, superficial lesion composed ofWell-circumscribed, superficial lesion composed of clusters of basaloid cells within a fibrous stroma. This arrangement of epithelial cells and stroma is described as organoid. The cystic spaces contain keratin. Notice the lackThe cystic spaces contain keratin. Notice the lack of mitotic figures or apoptotic bodies.

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), as shown in the image below.[12]

Papillary-mesenchymal bodies are structures associPapillary-mesenchymal bodies are structures associated with hair follicle differentiation. They are characterized by an aggregate of spindle, stromal cells, closely apposed to a hair bulb (arrow; darkly staining, basaloid epithelial cells).

Because trichoepitheliomas recapitulate hair differentiation, they may contain scattered melanocytes, as shown in the image below.

Because trichoepitheliomas recapitulate follicularBecause trichoepitheliomas recapitulate follicular differentiation, they may contain cells commonly seen in hair follicles such as melanocytes. This image illustrates both melanocytes (black arrow) and dermal melanophages (white arrow).

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, as shown in the image below.

Immunohistochemical studies detect expression of CImmunohistochemical studies detect expression of CD34 by many of the dendritic cells that surround the tumor aggregates (anti-CD34, diaminobenzidine, and hematoxylin).

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).[13] Trichoepitheliomas apparently lack expression of androgen receptors,[14] 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.[15, 16]

Although extremely rare, some trichoepitheliomas may develop high-grade carcinomas and biphasic tumors (epithelial and sarcomatous) with aggressive behavior (including metastasis).[17, 18]

Trichoepithelioma variants

The desmoplastic variant, as its name indicates, is characterized by a prominent, sclerotic stroma, as shown in the image below.[19]

Desmoplastic variant. Notice that many of the aggrDesmoplastic variant. Notice that many of the aggregates of basaloid cells are small, resembling a syringoma; however, they contain keratin instead of eccrine secretion. Also notice the characteristic markedly fibrous stroma.

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, as shown in the image below.

High-powered view of desmoplastic trichoepitheliomHigh-powered view of desmoplastic trichoepithelioma. Notice the cluster of squamous cells surrounding a small cystic area containing keratin. Intervening stroma is markedly fibrous.

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).[20, 21]

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.[22, 23, 24]

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.

The malignant counterpart is distinctly uncommon. Such lesions are characterized by a poorly circumscribed, infiltrative pattern of growth with areas of necrosis, as shown in the image below.

The malignant counterpart, trichilemmal carcinoma,The malignant counterpart, trichilemmal carcinoma, typically shows areas with infiltrative growth and necrosis.

Tumor cells in these cases show pleomorphic nuclei and large, pale staining cytoplasm. Some cells may contain characteristic red cytoplasmic trichohyalin granules, as shown in the image below.

Trichilemmal carcinoma cells have large, lightly sTrichilemmal carcinoma cells have large, lightly stained cytoplasm with large, pleomorphic nuclei. As a sign of follicular differentiation, some cells may display the characteristic cytoplasmic, red, trichohyalin granules (arrows).
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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 Pathology, 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.

Specialty Editor Board

Evan R Farmer, MD  Clinical Professor of Pathology and Dermatology, Department of Pathology, Virginia Commonwealth University School of Medicine

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.

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.

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.

Catherine M Quirk, MD  Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania

Catherine M Quirk, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD  Director, Department of Dermatology, Geisinger Medical Center

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

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, Teszas 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. Wang FX, Yang LJ, Li M, Zhang SL, Zhu XH. A novel missense mutation of CYLD gene in a Chinese family with multiple familial trichoepithelioma. Arch Dermatol Res. Jan 2010;302(1):67-70. [Medline].

  5. Huang TM, Chao SC, Lee JY. A novel splicing mutation of the CYLD gene in a Taiwanese family with multiple familial trichoepithelioma. Clin Exp Dermatol. Jan 2009;34(1):77-80. [Medline].

  6. Blake PW, Toro JR. Update of cylindromatosis gene (CYLD) mutations in Brooke-Spiegler syndrome: novel insights into the role of deubiquitination in cell signaling. Hum Mutat. Jul 2009;30(7):1025-36. [Medline].

  7. Martín de Las Mulas J, Molina AM, Millan 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].

  8. 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].

  9. Heller J, Roche N, Hameed M. Trichoepithelioma of the vulva: report of a case and review of the literature. J Low Genit Tract Dis. Jul 2009;13(3):186-7. [Medline].

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

  11. Espana A, Garcia-Amigot F, Aguado L, Garcia-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].

  12. 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].

  13. 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].

  14. 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].

  15. 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].

  16. Ramos-Ceballos FI, Pashaei S, Kincannon JM, Morgan MB, Smoller BR. Bcl-2, CD34 and CD10 expression in basaloid follicular hamartoma, vellus hair hamartoma and neurofollicular hamartoma demonstrate full follicular differentiation. J Cutan Pathol. May 2008;35(5):477-83. [Medline].

  17. 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].

  18. 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].

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

  20. 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].

  21. 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].

  22. 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].

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

  24. 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].

  25. Alessi SS, Sanches JA, de Oliveira WR, Messina MC, Pimentel ER, Festa Neto C. Treatment of cutaneous tumors with topical 5% imiquimod cream. Clinics (Sao Paulo). 2009;64(10):961-6. [Medline].

  26. 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].

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

 
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Characteristic clinical morphologic features. Notice the numerous, small papules, predominantly close to the midline.
Image of glass slide showing a nodular, very well-circumscribed proliferation.
Well-circumscribed, superficial lesion composed of clusters of basaloid cells within a fibrous stroma. This arrangement of epithelial cells and stroma is described as organoid.
The cystic spaces contain keratin. Notice the lack of mitotic figures or apoptotic bodies.
Papillary-mesenchymal bodies are structures associated with hair follicle differentiation. They are characterized by an aggregate of spindle, stromal cells, closely apposed to a hair bulb (arrow; darkly staining, basaloid epithelial cells).
Because trichoepitheliomas recapitulate follicular differentiation, they may contain cells commonly seen in hair follicles such as melanocytes. This image illustrates both melanocytes (black arrow) and dermal melanophages (white arrow).
Immunohistochemical studies detect expression of CD34 by many of the dendritic cells that surround the tumor aggregates (anti-CD34, diaminobenzidine, and hematoxylin).
Desmoplastic variant. Notice that many of the aggregates of basaloid cells are small, resembling a syringoma; however, they contain keratin instead of eccrine secretion. Also notice the characteristic markedly fibrous stroma.
High-powered view of desmoplastic trichoepithelioma. Notice the cluster of squamous cells surrounding a small cystic area containing keratin. Intervening stroma is markedly fibrous.
The malignant counterpart, trichilemmal carcinoma, typically shows areas with infiltrative growth and necrosis.
Trichilemmal carcinoma cells have large, lightly stained cytoplasm with large, pleomorphic nuclei. As a sign of follicular differentiation, some cells may display the characteristic cytoplasmic, red, trichohyalin granules (arrows).
 
 
 
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