[Cutaneous chondroid syringoma]

Chondroid syringoma (CS) is a rare cutaneous tumor characterized by mixte epithelial and mesenchymal component. The confident histological diagnosis can be obtained by immuno-histochemistry study. Here we present 10 new cases with their clinico-hystological characteristics.

The 10 cases were observed between January 2000 and august 2013, in Fort-de-France and Louis-Mourier universitary hospitals. For all the cases a controlled histological study was performed by a dermatopathologist expert and immuno-histochemistry was added. Clinical and immuno-histological data were analyzed.

The lesions were almost localized on the face (3/10) and the extremities (3/10). The size was about 1.2 to 5.2cm. Every case was treated by surgery, no malignant case was diagnosed. Histologically, all the 10 cases presented as a well-limited dermic tumor with a mixte epithelial and mesenchymal component. The stroma was myxo-chondroid, and the epithelial component consisted in epithelial cavities lined by one or two cell layers with eccrine (4/10) or apocrine (5/10) features. Immuno-chemistry study reveals positivity for EMA, ACE and CK7 for the internal cells, and positivity for S100 protein and vimentin of the extern cell layer.

Chondroid syringoma is characterized by a mixte epithelial with eccrine and apocrine cells and a myxo-chondroid stroma. Our study has some clinical and histological particularities (lesions on the extremities, epidermic connecting…). The main differentials diagnoses are the other annexial tumors. The treatment is surgical.

The histological diagnosis of CS is quite easy, but in case of doubt, immuno-chemistry will help, showing a double mesenchymal and epithelial differentiation.