Hairy cell sarcoma.

A 39-year-old coal merchant presented to his family practitioner with a seven month history of swelling of the left side of his face. He was referred to hospital where a left parotid mass was noted. All routine haematological and biochemical investigations were normal. A needle biopsy of the parotid mass, showed, on light microscopy using mercury based fixation, the presence of cells whose appearance was suggestive of hairy cell leukaemia. The cells failed to stain with acid phosphatase, non-specific esterase, chloroacetate esterase, periodic acid schiff and unna pappenheim/alcian blue. Bone marrow aspiration and trephine showed no evidence of leukaemia. Computed tomography of the chest and abdomen revealed no other deposits. The patient proceeded to surgery, where a mass infiltrating the superficial part of the parotid gland was excised. Electron microscopy showed it to be composed of typical hairy cells (Fig. 1). Post-operatively the parotid area and the whole of the lymphatic drainage of both sides of the neck from basicranium to clavicles was irradiated, using a radiocobalt unit. Lateral fields were applied and tissue compensators used. A tumour dose was delivered of 3500 cGy in 25 fractions over 29 days. Two years after presentation the patient is well without systemic evidence of hairy cell leukaemia. Discussion