Dermoscopic and Reflectance Confocal Microscope Findings of Trichoepithelioma

Abstract

Background: Trichoepitheliomas (TE) are benign neoplasms of follicular differentiation. Solitary lesions are often confused with basal cell carcinoma (BCC). Reflectance confocal microscopy (RCM) and dermoscopy are imaging tools for in vivo, noninvasive evaluation of skin lesions. To date, there has been no description of their findings in the evaluation of TE. Objective: Our aim is to describe the dermoscopic and RCM findings of histopathologically confirmed TE. Methods: Four TE were evaluated, 2 each of the desmoplastic and nondesmoplastic variants. RCM was performed on 1 of the desmoplastic and both of the nondesmoplastic lesions. Results: Dermoscopically, all of the lesions showed arborizing telangiectasias. The desmoplastic lesions also had an ivory-white background throughout. RCM showed oval, darker-appearing tumor islands that contained brightly refractile material, consistent with keratin horn cysts at the center, as well as parallel bundles of highly refractile dermal collagen surrounding the tumor islands. Conclusion: The ivory-white background throughout the lesion seen on dermoscopy may be helpful in distinguishing desmoplastic TE from BCC. The RCM findings in TE of keratin-filled cysts in tumor islands and attachment of the tumor to follicular structures have not been previously observed in BCC, and thus may also be diagnostically helpful. Further study is necessary for validation of these findings.

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

“…The three cases examined within the present study exhibited the typical clinical and histopathological features of DTE that have been described by previous studies (4,5,10). The depressed, non-ulcerating, and raised angular border that is described in previous studies (4,5,10) was a typical feature in the present cases.…”

“…Diagnosis based only on the clinical background may be difficult is certain cases, and for those cases, biopsy may be of use. The (10). Clinically, DTE is difficult to distinguish from other skin lesions caused by certain diseases, such as breast cancer.…”

Adult Xanthogranuloma Mimicking Basal Cell Carcinoma: Dermoscopy, Reflectance Confocal Microscopy and Pathological Correlation

“…No other specific criteria described by dermoscopy or RCM for BCC were seen in this tumor [10,13]. Ardigo et al have also described how the combination of dermoscopy and RCM helps the differentiation of a benign neoplasm (trichoepithelioma) from BCC [18]. …”

Dermoscopic Findings of Pilomatricomas

“…Moreover, melanoma usually presents other features of a melanocytic lesion, such as an atypical pigment network, atypical dots or globules, pseudopods, blue-white veil, negative pigment network, etc., which help distinguish it from pilomatricomas [13,14,15,16,17]. Finally, these focal irregular whitish structures of pilomatricomas are easy to differentiate from the orange-yellow ‘setting-sun’ coloration of juvenile xanthogranulomas [20] and the ivory-white background of the trichoepitheliomas [21], both localized in the whole of these tumors.…”