Fibrohistiocytoma: a rare tumour of the trachea.

Fibrohistiocytomas of the trachea are rare tumours of the trachea. It may be difficult on hist-ology to distinguish benign and malignant disease and expert opinion is required. These tumours can be successfully excised through inter-ventional rigid bronchoscopy. A 54-year-old Caucasian male was referred with haemoptysis. There was no associated dyspnoea, noisy breathing or loss of weight. His medication consisted of montelukast and loratidine for allergic rhinitis. Family history included his father having a pituitary tumour and grandfather having a liver tumour. He had no known allergies, and he had never smoked. He was a retired electronics engineer and may have been exposed to asbestos and beryl-lium in the past. Examination of the pharynx, car-diovascular, respiratory and gastrointestinal systems was normal. Investigations revealed a normal full blood count, coagulation profile, inflammatory markers and biochemistry. A postero-anterior chest radiograph was unremarkable, and the patient had flexible bron-choscopy to identify a cause of his haemoptysis. At bronchoscopy, an exophytic lesion of the trachea just below the vocal cords was seen. Computed tomography (CT) demonstrated a small polyp in the posterior wall of the trachea just below the vocal cords, and subsequent positron emission tom-ography-CT (PET-CT) demonstrated that the lesion was not 18-fludeoxyglucose avid. The tracheal lesion was excised using a carbon dioxide laser delivered through a micromanipulator attached to an operating microscope, using a line-of-sight technique during suspension laryngos-copy, with supraglottic high-frequency jet ventilation 1 under general anaesthesia (Figure 1A). Macroscopic appearance was a 10 Â 8 Â 6 mm firm exophytic lesion. Microscopically, the lesion was composed of spindle cells with indistinct margins and large vesicular oval nuclei, described as epithelioid and histiocytoid in appearance. There was focal necrosis but no granulomas were seen, and Ziehl Neelson and diastase resistant periodic acid-Schiff histochemical stains for acid-fast bacilli and fungi were negative. Mitotic figures were identified (2 per 10 high-power fields counted) (Figure 1B). Immunohistochemistry was not diagnostic. It showed patchy staining for S100 protein and smooth muscle actin and weak focal staining for epithelial membrane antigen. A striking presence of CD1a positive cells and a smaller proportion of CD68 cells were noted. The lesion was negative for skeletal muscle markers and epithelial markers. No neoplastic lymphoid process was demonstrated on