Pleomorphic Malignant Fibrous Histiocytoma of the Periorbital Region

BACKGROUND: Pleomorphic malignant fibrous histiocytomas (undifferentiated pleomorphic sarcomas) belong to the soft tissue tumours and are more likely in elder patients. About 3 % percent of all pleomorphic malignant fibrous histiocytomas arise in the head and neck region. 30 % of these histiocytomas develop in the paranasal sinuses. Occurrence in the periorbital region is a very rare event. In spite of their pleomorphic pattern the treatment is solely surgical excision. Haematogenic or loco-regional lymphogenic metastases are very rare. PATIENT: A 91 year old female patient presented because of a prominent tumour in the upper right periorbital region. As stated in the case history, the tumour had developed within the previous 6 months. The tumour measured about 3 × 4 cm. It was tight to resiliant and seemed to not be adherent to the underlying structures. Pain or hypesthaesia were not existent. Due to the mass of the tumour a ptosis was present. Additionally, there was a mechanical lack in the movement of the eyeball in the upper direction. The papilla was vital and differentiated. Visual acuity was decreased due to a mature cataract. CLINIC: Neither CT nor MRI could give a clue to the tumour entity. Infiltration of the periorbital structures or the eyeball could not be ruled out. A biopsy was classified as a malignant fibrous tumour with the subclassification of an atypical fibroxanthoma. The final histopathological classification after total excision of the tumour showed perineural growth and angioinvasion. Therefore the tumour classification was changed to pleomorphic malignant fibrous histiocytoma (undifferentiated pleomorphic sarcoma). The defect was closed with a full skin graft on the basis of a galea periosteal flap. CONCLUSION: The histopathological examination could not provide the correct diagnosis initially. Immunohistochemical stainings (Vimentin) were carried out to characterise the tumour. This underlines that even with state of the art procedures the classification of neoplasias can be very difficult. In the process of finding the right diagnosis sometimes a change from benign to malignant occurs and alters the treatment regime.