Intestinal Behçet’s disease complicated by myelodysplastic syndrome and secondary pulmonary alveolar proteinosis: a case report

BACKGROUND: Gastrointestinal lesions, which sometimes develop in Behçet’s disease (BD), are referred to as intestinal BD. Although rare, intestinal BD can be accompanied by myelodysplastic syndrome (MDS) with abnormal karyotype trisomy 8, which is refractory to immunosuppressive therapy. Pulmonary alveolar proteinosis is a rare lung complication of BD and MDS. Herein, we present an extremely rare case of intestinal BD presenting with MDS and several chromosomal abnormalities, followed by secondary pulmonary proteinosis. CASE PRESENTATION: A 58-year-old Japanese woman with a 3-year history of genital ulcers and oral aphthae was admitted to our hospital. The patient developed abdominal pain and persistent diarrhea. Colonoscopy revealed multiple, round, punched-out ulcers from the terminal ileum to the descending colon. Intestinal BD was diagnosed and the patient was treated with colchicine, prednisolone, and adalimumab. However, her symptoms were unstable. Bone marrow examination to investigate the persistent macrocytic anemia revealed the presence of trisomy 8, trisomy 9, and X chromosome abnormalities (48, + 8, + 9, X, i(X) (q10) in 12 out of the examined 20 cells). Based on her hypoplastic bone marrow, the patient was diagnosed with low-risk MDS (refractory anemia). At the age of 61, the patient developed pneumonia with fever and diffuse ground-glass opacities on the lung computed tomography (CT). Chest high-resolution CT and histopathology via transbronchial lung biopsy revealed the presence of pulmonary alveolar proteinosis (PAP). These findings combined with the underlying disease led to the diagnosis of secondary PAP. CONCLUSIONS: Secondary pulmonary proteinosis may accompany intestinal BD with MDS and several chromosomal abnormalities. Physicians should pay attention to lung complications, such as PAP, in patients with intestinal BD complicated by MDS. Genetic abnormalities may be associated with the development of such diseases.