DERMOSCOPY
CASES OF THE MONTH
Trichoblastoma with dermoscopic features of a malignant tumor: Three cases Alexandra Picard, MD,a Katerina Tsilika, MD,a Nathalie Cardot-Leccia, MD,b Thierry Passeron, PhD,a Jean-Philippe Lacour, PhD,a and Philippe Bahadoran, PhDa,c Nice, France
CLINICAL PRESENTATION Case 1 was a 70-year-old man who presented with an erythematous 1.2-cm frontal nodule that had appeared recently (Fig 1, A). Case 2 was a 68-year-old woman who presented with a left temporal sebaceous nevus, associated with a recent onset of an overlying nodular skin lesion that was 2.0 3 0.7 cm (Fig 2, A). Case 3 was a 57-year-old woman who presented with a pigmented nodular lesion of unknown onset on her right shoulder (Fig 3, A).
Fig 1. Case 1. A, An erythematous frontal nodule. B, Dermoscopy revealing milky red areas (thick arrowhead ), a central whitish veil (thin arrowhead ), and ‘‘tree-like’’ arborizing telangiectasias (arrows).
Fig 2. Case 2. A, Left temporal sebaceous nevus associated with the recent development of an overlying nodular lesion. B, Dermoscopy revealing yellow plate (thick arrowhead ), a whitish region (thin arrowhead ), and ‘‘tree-like’’ telangiectasias (arrow). From the Department of Dermatology,a University Hospital of Nice, Archet 2 Hospital, Department of Pathology,b University Hospital of Nice, Pasteur Hospital, and the Clinical Research Centre,c University Hospital of Nice. Funding sources: None. Conflicts of interest: None declared. Correspondence to: Alexandra Picard, MD, Department of Dermatology, University Hospital of Nice, Archet 2 Hospital,
151 Rte de St-Antoine de Ginestiere, 06200 Nice, France. E-mail: [email protected]. J Am Acad Dermatol 2014;71:e63-4. 0190-9622/$36.00 ª 2014 by the American Academy of Dermatology, Inc. http://dx.doi.org/10.1016/j.jaad.2013.12.033
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SEPTEMBER 2014
Fig 3. Case 3. A, Right shoulder pigmented lesion (arrow). B, Dermoscopy revealing a gray-bluish homogeneous area (thick arrow), a hypopigmented area (arrowhead ), and a subtle pigmented network (arrow).
DERMOSCOPIC EXAMINATION Dermoscopy of the first nodule revealed a well circumscribed lesion with a milky red area, a central whitish veil, and thick, arborizing, ‘‘tree-like’’ telangiectasia (Fig 1, B). Figure 2, B revealed a yellow plate, a whitish region, and ‘‘tree-like’’ telangiectasia as well. In case 3, dermoscopy revealed a graybluish homogeneous area in the center of the lesion, hypopigmented areas, and a subtle pigmented network (Fig 3, B).
HISTOLOGIC DIAGNOSIS Histopathologic examinations confirmed the diagnosis of trichoblastoma for all 3 cases.
KEY MESSAGE Trichoblastoma is a rare benign skin tumor of rudimentary hair follicles. It can be primitive or complicate the evolution of a sebaceous nevus. In the first 2 cases, the presence of prominent arborizing telangiectasias was suggestive of basal cell carcinoma. This misleading feature could be explained by some histologic similarities between the 2 tumors.1,2 In the third case, the presence of blue-gray areas were more suggestive of nodular melanoma, but this finding was attributed to Tyndall scattering, as reported for other adnexal tumors. In conclusion, these dermoscopic patterns of trichoblastoma may be misleading and should be recognized by dermatologists in order to avoid diagnostic pitfalls.
REFERENCES 1. LeBoit PE. Trichoblastoma, basal cell carcinoma, and follicular differentiation: what should we trust? Am J Dermatopathol 2003; 25:260-3. 2. Hamasaki H, Koga K, Hamasaki M, Kiryu H, Nakayama J, Iwasaki H, et al. Immunohistochemical analysis of laminin 5-g2 chain expression for differentiation of basal cell carcinoma from trichoblastoma. Histopathology 2011;59:159-61.
CASES OF THE MONTH
Trichoblastoma with dermoscopic features of a malignant tumor: Three cases Alexandra Picard, MD,a Katerina Tsilika, MD,a Nathalie Cardot-Leccia, MD,b Thierry Passeron, PhD,a Jean-Philippe Lacour, PhD,a and Philippe Bahadoran, PhDa,c Nice, France
CLINICAL PRESENTATION Case 1 was a 70-year-old man who presented with an erythematous 1.2-cm frontal nodule that had appeared recently (Fig 1, A). Case 2 was a 68-year-old woman who presented with a left temporal sebaceous nevus, associated with a recent onset of an overlying nodular skin lesion that was 2.0 3 0.7 cm (Fig 2, A). Case 3 was a 57-year-old woman who presented with a pigmented nodular lesion of unknown onset on her right shoulder (Fig 3, A).
Fig 1. Case 1. A, An erythematous frontal nodule. B, Dermoscopy revealing milky red areas (thick arrowhead ), a central whitish veil (thin arrowhead ), and ‘‘tree-like’’ arborizing telangiectasias (arrows).
Fig 2. Case 2. A, Left temporal sebaceous nevus associated with the recent development of an overlying nodular lesion. B, Dermoscopy revealing yellow plate (thick arrowhead ), a whitish region (thin arrowhead ), and ‘‘tree-like’’ telangiectasias (arrow). From the Department of Dermatology,a University Hospital of Nice, Archet 2 Hospital, Department of Pathology,b University Hospital of Nice, Pasteur Hospital, and the Clinical Research Centre,c University Hospital of Nice. Funding sources: None. Conflicts of interest: None declared. Correspondence to: Alexandra Picard, MD, Department of Dermatology, University Hospital of Nice, Archet 2 Hospital,
151 Rte de St-Antoine de Ginestiere, 06200 Nice, France. E-mail: [email protected]. J Am Acad Dermatol 2014;71:e63-4. 0190-9622/$36.00 ª 2014 by the American Academy of Dermatology, Inc. http://dx.doi.org/10.1016/j.jaad.2013.12.033
e63
e64 Picard et al
J AM ACAD DERMATOL
SEPTEMBER 2014
Fig 3. Case 3. A, Right shoulder pigmented lesion (arrow). B, Dermoscopy revealing a gray-bluish homogeneous area (thick arrow), a hypopigmented area (arrowhead ), and a subtle pigmented network (arrow).
DERMOSCOPIC EXAMINATION Dermoscopy of the first nodule revealed a well circumscribed lesion with a milky red area, a central whitish veil, and thick, arborizing, ‘‘tree-like’’ telangiectasia (Fig 1, B). Figure 2, B revealed a yellow plate, a whitish region, and ‘‘tree-like’’ telangiectasia as well. In case 3, dermoscopy revealed a graybluish homogeneous area in the center of the lesion, hypopigmented areas, and a subtle pigmented network (Fig 3, B).
HISTOLOGIC DIAGNOSIS Histopathologic examinations confirmed the diagnosis of trichoblastoma for all 3 cases.
KEY MESSAGE Trichoblastoma is a rare benign skin tumor of rudimentary hair follicles. It can be primitive or complicate the evolution of a sebaceous nevus. In the first 2 cases, the presence of prominent arborizing telangiectasias was suggestive of basal cell carcinoma. This misleading feature could be explained by some histologic similarities between the 2 tumors.1,2 In the third case, the presence of blue-gray areas were more suggestive of nodular melanoma, but this finding was attributed to Tyndall scattering, as reported for other adnexal tumors. In conclusion, these dermoscopic patterns of trichoblastoma may be misleading and should be recognized by dermatologists in order to avoid diagnostic pitfalls.
REFERENCES 1. LeBoit PE. Trichoblastoma, basal cell carcinoma, and follicular differentiation: what should we trust? Am J Dermatopathol 2003; 25:260-3. 2. Hamasaki H, Koga K, Hamasaki M, Kiryu H, Nakayama J, Iwasaki H, et al. Immunohistochemical analysis of laminin 5-g2 chain expression for differentiation of basal cell carcinoma from trichoblastoma. Histopathology 2011;59:159-61.
