Desmoplastic trichoepithelioma: A clinicopathological study of three cases and a review of the literature

Abstract

Desmoplastic trichoepithelioma (DTE) is a rare benign adnexal tumor with the characteristic features of asymptomatic, solitary, annular, indurated and centrally depressed papules or plaques, most commonly occurring in younger individuals on the face. Microscopically and clinically, DTE may be difficult to distinguish from other cutaneous adnexal neoplasms, particularly syringoma, cutaneous metastatic breast cancer, morpheaform basal cell carcinoma and microcystic adnexal carcinoma. The present study reports three cases of DTE. The first case was of a 45-year-old male with an asymptomatic flesh-colored plaque below the right edge of the outer canthus that had been present for seven years. The second case was of a 23-year-old female with an asymptomatic skin lesion on the right cheek that had slowly and progressively increased in size. The third case was of a 26-year-old female who presented with a hard yellowish-white plaque, which gradually grew and formed a rectangular, 3×4-cm patch, on the tip of the left brow. This plaque was present for three years without evident cause or subjective symptoms. In all three cases, the routine systemic examinations and laboratory findings were normal. Histopathological and immunohistochemical findings from incisional biopsies of the lesions were consistent with a diagnosis of DTE. DTE treatment methods and immunohistochemical markers were analyzed by reviewing clinical pathological aspects in order to avoid a misdiagnosis and to provide the best available treatment approach for DTE.

Keywords: desmoplastic trichoepithelioma; microcystic adnexal carcinoma; morpheaform basal cell carcinoma.

Figure 1.

Case one: Microscopic appearance of the flesh-colored and centrally depressed lesion, with elevated borders, which was located laterally over the right periorbital region.

Figure 2.

Case one: Light microscopy biopsy revealed no clear abnormalties of the epidermis and the presence of a mass branching tumor cells at the shallow and middle dermis, as well as the proliferation of collagen (hematoxylin and eosin stain).

Figure 3.

Case one: Immunohistochemical staining showing (A) diffusely scattered cytokeratin 20-positive cells within strands of the tumor and (B) cluster of differentiation 34-positive cells surrounding the tumor mass; and negative (C) epithelial membrane antigen and (D) androgen receptor expression. Scale bars, 100 µm.

Figure 4.

Case two: Microscopic appearance of the small, flesh-colored, centrally depressed, bean-sized single lesion, with raised borders, which was located on the right cheek.

Figure 5.

Case two: Light microscopy biopsy revealed thickening of the epidermis and the presence of a mass of branching tumor cells at the shallow and middle dermis, as well as the proliferation of collagen (hematoxylin and esoin stain).

Figure 6.

Case two: Immunohistochemical staining revealing (A) a few cytokeratin 20-positive cells within the strands of the tumor and (B) cluster of differentiation 34-positive cells surrounding the tumor mass; negative (C) epithelial membrane antigen and (D) androgen receptor expression; and (E) weakly positive B-cell lymphoma 2 expression. Scale bars, 100 µm.

Figure 7.

Case three: Microscopic appearance of the hard yellowish-white plaque, which had formed a rectangular, 3×4-cm patch, and was located on the tip of the left brow.

Figure 8.

Case three: Light microscopy biopsy revealed mild atrophy of the epidermis and the presence of a mass of branching tumor cells at the shallow and middle dermis,a s well as the proliferation of collagen (hematoxylin and eosin stain).