Fiona Bonar

Telangiectatic dedifferentiation of a parosteal osteosarcoma.

Abstract A unique case of parosteal osteosarcoma (POS) of the proximal femur, with areas of telangiectatic dedifferentiation, in a 28-year-old woman is reported. The patient had a 7-week history of pain and swelling in her right thigh. A biopsy diagnosis of POS was established. The patient was treated with two cycles of intra-arterial chemotherapy, followed by limb salvage surgery. Histological examination of the resected specimen showed POS with areas of dedifferentiation composed of high-grade telangiectatic osteosarcoma with associated secondary aneurysmal bone cyst change.

Rarefaction of the aorta under Dacron wrap: a rare complication

Treatment for ascending aortic dilatation varies from a wait-and-watch approach to aortic replacement. The use of an external prosthesis to gird and support the proximal aorta is safe and durable for selected aortic aneurysms. We report a rare complication in a 62-year-old man with bicuspid aortic valve and coronary artery disease who had undergone coronary artery bypass surgery and ascending aortic wrapping 10 years previously. During subsequent aortic valve surgery, he was incidentally found to have erosion of Dacron wrap through the aortic wall.

Optimising the management of soft tissue tumours

The Royal College of Pathologists of Australasia is developing a series of protocols as an educational tool to assist pathologists in the reporting of relevant information for specific cancer specimens. The protocol for the management of soft tissue tumour resections has recently been released, and this document elaborates the relevant literature on which that protocol drew. Sarcoma is uncommon but is associated with significant morbidity and mortality, and its management is complex. Diagnostic errors are not uncommon and these can have disastrous effects on patient outcome. Sophisticated ancillary testing is often an important adjunct to diagnosis and prognostication. Referral to a specialist sarcoma unit is indicated for both adult and paediatric sarcoma.

48. An unusual presentation of Angiomatoid Fibrous Histiocytoma (AFH)

AFH accounts for 0.3% of all soft tissue tumours and typically affects the extremities of children and young adults. Classically, microscopically, fascicles and sheets of oval to spindle cells, pseudovascular spaces, haemorrhage and a fibrous pseudocapsule rimmed by a lymphocytic infiltrate are noted. However, some cases lack these typical features, often bearing a striking resemblance to organising haematoma. Recently, cytogenetic analysis of AFH has shown specific translocations involving the EWSR1 and FUS genes. We document a seventy-one year old man who presented with a recurrent lesion of the left triceps muscle, six years after surgical excision. The radiology, morphology and immunohistochemical profile (EMA, desmin negative) of the initial lesion were those of an organising haematoma. (The lesion was completely embedded). It’s true nature was only revealed at recurrence, where characteristic histological and immunohistochemical features of AFH were noted, prompting cytogenetic evaluation of both lesions. The EWSR1 rearrangement was present in the initial and recurrent lesion. Therefore, whilst morphological and immunohistochemical evidence of AFH were not present initially, recent cytogenetic advances have enabled confirmation of AFH at that time. This case illustrates the utility of cytogenetic testing in the diagnosis of AFH where the lesion deviates from the classical histological appearance. This possibility should be considered in haematomas in the absence of a specific cause at any age.

Bone tumours and tumour-like conditions of the head and neck and jaws

Almost all variants of malignant primary and secondary tumours of bone have been described as occurring within the head and neck and jaws. The most commonly occurring primary bone tumours affecting the jaws include osteosarcoma, Burkitt’s lymphoma and multiple myeloma, while secondary or metastatic tumours to the jaws are rare in contrast to the remainder of the skeleton. Management of patients with bone tumours and tumour-like lesions requires a team approach. Good communication between radiologist, attending head and neck surgeon and pathologist is imperative for accurate interpretation and diagnosis of these neoplasms. Pathologists who attempt to make a diagnosis of bony neoplasms without the clinical and radiographic information are at a distinct disadvantage and this is strongly discouraged. The objective of the slide seminar is to address some of the common as well as the less common bone tumours and tumour-like conditions of the head and neck and jaws.

4. Well-differentiated liposarcoma with unusual vascular component

Dedifferentiated liposarcoma accounts for up to 10% of liposar-comas, and is classically defined as a well-differentiated (WD) liposarcoma showing abrupt transition, either in the primary tumour or in the recurrence, to high grade non-lipogenic sarcoma. The most frequent sarcomas recognised in the dedifferentiated areas resemble storiform/pleomorphic malignant fibrous histiocy-toma (MFH), myxofibrosarcoma or sarcoma not otherwise specified. We report a unique case of WD liposarcoma of the lower limb that shows an unusual vascular component, which we favour to represent a low grade angiosarcomatous dedifferentiation. To the best of our knowledge, there are only two cases of angiosarcoma arising from dedifferentiation of a liposarcoma, neither of which occur in a limb.