Korean J Pathol.
2000 Aug;34(8):574-580.
Trichoblastic Fibroma: A Pathologic Analysis of 4 Cases
- Affiliations
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- 1Department of Clinical Pathology, College of Medicine, The Catholic Universiry of Korea, Seoul 137-040, Korea
Abstract
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Trichoblastic fibroma is a benign trichogenic tumor that has both epithelial and
mesenchymal components and exhibits partial follicular induction. We studied 4 cases of
trichoblastic fibroma and reviewed their clinical and histologic features. Two tumors
were present in the face. The remaining two were in the vulva and perianal area,
respectively. The age of the patients ranged from 53 to 68 years, with an average age
of 62. All were female. Histologically, the lesions showed a well circumscribed mass,
located at dermo-subcutaneous junction in three patients and subcutaneous in one. They
demonstrated mesenchymal induction evidenced by hair germ-like structure and
perifollicular sheath. There was no connection between the tumor and epidermis.
Differentiation toward hair structure led to the formation of the infundibulum through
inner root sheath. Trichoblastic fibroma may be confused clinically and/or histologically
with basal cell carcinoma. Identification of the mixed epithelial and mesenchymal
components, and the absence of epidermal connection and cleft within the stroma are
important in differentiating this benign neoplasm from basal cell carcinoma.