Plexiform fibrohistiocytic tumour (TFHP) is a rare mesenchymal neoplasm of intermediate malignancy but with a high rate of local recurrence and potential for lymph node or pulmonary metastases. It usually affects superficial soft tissues of the upper extremities of children and young adults and is more frequent in females.We report a case of a 10 year old boy with progressive tumour growth, under the skin in the right knee with ipsilateral inguinal lymphadenopathy. He underwent wide resection of the lesion with inguinal lymphadenectomy. Histopathology revealed a plexiform pattern with a biphasic component (mononuclear histiocytic cells associated with CD68 positive osteoclast-like giant cells and smooth muscle actin-positive spindle cells); favoring the diagnosis of TFHP with lymph node metastasis.