Storiform Pattern

A pattern seen by low-power light microscopy, which is characterised by loosely-arranged whorls of elongated, spindled fibroblast-like cells. The highly nonspecific storiform pattern is often seen in fibrohistiocytic lesions. It may be benign—e.g., dermatofibroma, giant cell tumour of tendon sheath—of low malignant potential—e.g., atypical fibroxanthoma, dermatofibrosarcoma protuberans—or malignant—e,g, fibrosarcoma; it may also be seen in non-histiocytic lesions—e.g., nodular fascitis, leiomyoma, leiomyosarcoma, Schwann cell tumours, spindle cell carcinoma