A 26-year-old male pre-operative transsexual presented to the emergency dept of the University of Texas Southwestern Medical Center (TX, USA) with complaints of acute dyspnoea and frank haemoptysis. The patient did not use intravenous or illicit drugs, alcohol or tobacco, but had a history of unprotected homosexual intercourse. On physical examination, the patient was in severe respiratory distress, with a respiratory rate of 38 breaths per minute and accessory muscle use. The physical examination revealed subcutaneous emphysema, diffuse bilateral crackles, and mediastinal crepitus consistent with a Hamman's crunch. The patient had decreased facial and body hair, moderate breast augmentation and male genitalia. Arterial blood gases on room air revealed a pH 7.43, carbon dioxide tension (PCO 2 ) 4.66 kPa (35 mmHg), arterial oxygen tension (Pa,O 2 ) 4.39 kPa (33 mmHg) and 65% saturation. The patient was placed on a high-flow oxygen mask (non-rebreather mask), and subsequent arterial blood gases showed a pH 7.43, PCO 2 5.05 kPa (38 mmHg), Pa,O 2 7.98 kPa (60 mmHg) and 89% saturation.Laboratory data revealed a haematocrit of 27% (0.27), a normal white blood cell count and an unremarkable coagulation profile. Serum chemistries revealed an elevated lactic dehydrogenase of 252 U·L -1 (normal range 100-190 U·L -1 ). A urinary toxicology screen was negative for cocaine or opiates. The patient was empirically treated for Pneumocystis carinii pneumonia (PCP) and severe community-acquired pneumonia, with intravenous methylprednisolone, trimethoprim/sulphamethoxazole and ticarcillin/clavulanate.Blood, sputum and urine bacterial cultures were negative. Sputum samples were negative for P. carinii by direct fluorescent antibody and stains for acid-fast bacilli (AFB). An HIV antibody test was negative. The CD4 count was 103 cells·mm -3 (normal range 416-1,751 cells·mm -3 ) and HIV viral load was <400 copies·mL -1 (limit of detection <400 copies·mL -1 ). Serial bronchoalveolar lavage (BAL) revealed increasingly bloody returns consistent with diffuse alveolar haemorrhage. The first aliquot contained 465,000 red blood cells·µL -1 and 800 nucleated cells·µL -1 (67% neutrophils, 25% monocytes, 3% lymphocytes, 2% mesothelial cells, 3% eosinophils), while aliquot number four contained 510,000 red blood cells·µL -1 and 300 nucleated cells·µL -1 (77% neutrophils, 15% monocytes, 2% lymphocytes, 3% mesothelial cells, 2% eosinophils). BAL stains were negative for PCP, AFB, and fungal and bacterial pathogens. Serum anti-neutrophil cytoplasmic antibody and anti-glomerular basement membrane antibodies were negative.A computed tomography (CT) scan was performed on the patient and is shown in figure 1. The patient's original BAL fluid was further examined with Sudan stain and an example of this is shown in figure 2.