Medallion-like dermal dendrocyte hamartoma: the main diagnostic pitfall is congenital atrophic dermatofibrosarcoma

Abstract

Medallion-like dermal dendrocyte hamartoma is a newly described and rare clinical and pathological entity. This congenital, round, erythematous and atrophic lesion in the thoracic area is histologically characterized by a CD34+ dermal and hypodermal spindle-cell infiltration. We describe the clinical, histopathological, cytological and molecular features of three cases of dermal dendrocyte hamartoma. In all the cases, atrophic congenital dermatofibrosarcoma protuberans (DFSP) was the first histological diagnosis. In one case, wide surgery had been performed on the basis of the clinical and histological presentation. The histological pattern was similar in all the cases: epidermal atrophy and a spindle to ovoid cell proliferation in the dermis and in the subcutaneous fat. Immunochemical staining for CD34 and factor XIIIa was positive. Cytogenetic and molecular studies were performed; no chromosomal abnormality nor translocation t(17;22)(q22;q13) was observed. Fluorescence in situ hybridization analysis did not reveal the DFSP fusion gene COL1A1-PDGFB. We observed that the main diagnostic pitfall of medallion-like dermal dendrocyte hamartoma is atrophic congenital DFSP due to clinical and histological similarities. We emphasize that molecular studies to eliminate the t(17;22)(q22;q13) translocation of DFSP may provide determinant elements for diagnosis in order to avoid unnecessary mutilating surgery.

A Case of Medallion-Like Dermal Dendrocyte Hamartoma with a Distinctive Size and Vascular Component

“…Histopathological findings are characterized by epidermal atrophy and the presence of CD34+ spindle cell proliferation in the dermis [1][2][3][4]. Nine cases have been reported in English literature so far [1][2][3][4][5][6]. Our case had similar clinical and histopathological features as previously reported cases except for distinctive size and vascular component.…”

“…Then, Rodriguez-Jurado et al described MLDDH firstly as an atrophic lesion [1]. All previous reported cases were well-demarcated, round, triangular or oval erythematous and atrophic plaques of several centimeters in diameter [1][2][3][4][5]. Blood vessels and telangiectasias were seen below some of the lesions [1,5].…”

“…Presumptive clinical diagnoses are dermatofibrosarcoma protuberans (DFSP), morphea, anetoderma, atrophoderma. MLDDH can be confused with DFSP, because both of them are positive for CD34 [3]. It is a rare locally infiltrative malignant cutaneous dermal or subcutaneous tumor [8].…”

“…Skin biopsy specimens of each nine patients included epidermal atrophy and presence of CD34 positive spindle cell proliferation in the dermis [1][2][3][4][5]. Immunohistochemical profile of the cases were shown in Table 2.…”

“…Also, underlying blood vessels and telangiectasias may be visible [2]. Histopathological findings are characterized by epidermal atrophy and the presence of CD34+ spindle cell proliferation in the dermis [1][2][3][4]. Nine cases have been reported in English literature so far [1][2][3][4][5][6].…”