Pathogenesis (disease development)
Malignant fibrous histiocytoma (MFH) is a fibrohistiocytic tumor, meaning that the cells resemble a fibroblast (connective tissue cell) on the one hand and a histiocyte (resident phagocyte) on the other. Thus, a pleomorphic (multiform) appearance is present. The tumor arises from mesenchymal tissue (mesenchyme = part of the embryonic connective tissue). This includes bone and muscle tissue as well as fatty and peripheral nerve tissue.
The cells of a malignant fibrous histiocytoma are poorly differentiated.The malignant fibrous histiocytoma may produce collagens and release them into the extracellular space. An extracellular matrix is then formed.
Etiology (Causes)
The exact causes of primary malignant fibrous histiocytoma (MFH) are still unclear.Secondary malignant fibrous histiocytoma may develop because of a preexisting tissue lesion (see below).
Secondary malignant fibrous histiocytoma (approximately 20% of cases).
Disease-related causes
- In scar tissue – in MFH of the skin.
- In sites of chronic inflammation – in MFH of the skin.
- Enchondroma – benign (benign) bone tumor originating from cartilage tissue.
- Fibrous dysplasia – malformation of bone tissue, that is, the bones form tumor-like protrusions.
- Bone fracture (bone fracture)
- Bone infarction (demise of bone tissue).
- Paget’s disease – disease of the skeletal system in which there is a gradual thickening of several bones.
- Osteomyelitis (bone marrow inflammation).
Other causes
- Surgical intervention
- In irradiated areas (radiatio/radiotherapy) – for MFH of the skin.
