Acute fibrinous and organizing pneumonia in a patient with myelodysplastic syndrome and a complex chromosomal abnormality: a case report

Acute fibrinous and organizing pneumonia (AFOP) is a rare form of acute lung injury characterized by intra-alveolar fibrin deposition rather than the hyaline membranes seen in diffuse alveolar damage. Although AFOP has been associated with several systemic conditions, its occurrence in patients with myelodysplastic syndrome (MDS) is extremely rare. Diagnosis is challenging because AFOP can closely mimic infectious pneumonia. We present a case of AFOP in a patient with MDS and a complex chromosomal abnormality, highlighting the diagnostic challenges and the unusual co-occurrence of these findings. A 65-year-old female with a history of MDS presented with progressive dyspnea and cough. Chromosomal analysis of her MDS revealed a complex karyotype: 46,XX,+1,der(1;21)(q10;q10),del(5)(q15;q35). She developed bilateral pulmonary consolidations that were unresponsive to broad-spectrum antimicrobial therapy. A CT-guided lung biopsy was crucial in excluding infection and establishing the diagnosis of AFOP based on the presence of intra-alveolar fibrin “balls” and organizing pneumonia. Short-course high-dose intravenous methylprednisolone followed by a structured taper resulted in significant clinical and radiographic improvement. However, the patient ultimately succumbed to the progression of her underlying MDS several months later. AFOP should be considered as a treatable non-infectious cause of pulmonary consolidation in patients with hematologic disorders such as MDS. This case supports early tissue biopsy when pulmonary infiltrates fail to respond to antimicrobial therapy. Although the der(1;21) chromosomal abnormality was identified in this patient, no causal relationship between this cytogenetic finding and AFOP can be inferred from a single case. Prompt recognition and corticosteroid therapy may reverse respiratory deterioration, while long-term outcome remains strongly influenced by the underlying hematologic disease.