Clear cell sarcoma: a case mimicking primary cutaneous malignant melanoma

Abstract

Clear cell sarcoma (CCS) is a recently described variant of sarcoma characterized by prominent clear cells showing features similar to clear cell melanoma. This neoplasm was first described by Dr. Franz M. Erzinger. Primary CCS usually arises in deeper soft tissues, in association with fascia, tendons, or aponeuroses. Characteristic translocation t(12;22) (q13;q12) has been considered pathognomonic for CCS. Prognosis is related to tumor size. An early recognition and initial radical surgery is the key to a favourable outcome. We present a patient with an unusual neoplasm that resembled malignant melanoma.

Keywords: Clear cell sarcoma; genetic studies; malignant melanoma.

Figure 1

On the right arm, an erythematous, dome-shaped, nodular lesion, 1.3 cm in diameter with a serohemorragic crust on its surface could be observed. No other relevant lesions were found on total skin examination

Figure 2

(a) In a low power picture, oval to polygonal in shape cells with a clear cytoplasm and irregular nuclear contours and complex nucleoli can be observed. Cells were disposed in nests separated by fibrous connective tissue. (b) Intraepidermal involvement can be observed. (H&E, ×40); (c) In dermis, cells were disposed in nests separated by fibrous connective tissue, showing an alveolar pattern (H&E, ×40); (d) Neoplastic cells displayed positivity for HMB 45; and (e) Positivity for S-100 protein.

Figure 3a and b

FISH technique: A single-stranded probe was used to hybridize with a specific DNA sequence of the sample. In this case, we used the LSI CHOP (12q13) Dual Color, Break Apart Rearrangement Probe (Abbott Laboratories), which showed the nuclei of normal cells with two fusion signals, whereas the signal pattern of abnormal cells was one orange, one green, and one fusion signal