[Myxoid plexiform fibrohistiocytic tumor without multinucleated giant cells]

Plexiform fibrohistiocytic tumour is a rare soft-tissue tumour of intermediate malignancy. It is more prevalent in children and in young adults. We report a case of this tumour presenting as a nontender swelling on the shoulder of an 8-year-old girl. Clinically, the mass was subcutaneous and measured 2 cm in greatest diameter. The histopathological examination revealed a mesenchymal dermic and subcutaneous tumour composed of confluent nodules. These nodules were made of aggregates of histiocyte-like cells and concentric fascicles of spindle cells. The stroma was myxoïd or collagenous. This case was particular by the lack of giant cells and the focally myxoid background. The epidemiologic, clinicopathologic features and outcome of this lesion are discussed and similar published cases are reviewed.