Malignant fibrous histiocytoma of salivary gland

Abstract

Soft tissue tumours of all solid organs are uncommon. In the salivary gland soft tissue tumours comprise less than 5% of all primary neoplasms with malignant neoplasms representing less than 20% of these (1). The majority of soft tissue tumours of the salivary gland are haemanglomas, lymphanglomas, neurilemmomas, neurofibroma and lipomas. The vast majority of malignant neoplasms are lymphomas Involving usually the intra-parotid lymph nodes. Malignant soft tissue tumours are extremely rare. A 78 year old male presented to Caulfield General Medical Centre with peripheral vascular disease and en passant was noted to have a a painless 20mm diameter swelling at the lower pole of the right parotid gland Excisional biopsy showed a poorly defined hard white tumour mass replacing the parotid tissue. Histological examination showed a malignant spindle cell tumour with bizarre forms. The tumour was positive for vimentin and alpha-1-antitrypsin. Electron microscopy showed features consistent with cells of fibroblastic and histiocytic origin. Malignant fibrous histlocytoma arising primarily In the salivary gland has been described on 7 previous occasions, with 6 previous cases in the parotid and one In the submandibular gland. The tumour has a marked male predominance (7M:1F).The lesion occurs between 25 and 78 years of age with a median age of 51 years. The tumour was more common on the right side. Six of the eight patients have survived more than 2 years since diagnosis with the longest surviving patient alive with skin recurrence at 6 years post-operative.