Pulmonary extramedullary haematopoiesis

Area of Science:

• Hematology
• Pulmonology
• Pathology

Background:

• Myeloproliferative disorders (MPDs) are a group of conditions that affect blood cell production.
• Extramedullary hematopoiesis (EMH) is the formation of blood cells outside of the bone marrow.
• Pulmonary involvement in MPDs is uncommon, with various potential causes for respiratory symptoms.

Observation:

• A 72-year-old female with MPD presented with dyspnea, weight loss, fatigue, and hypoxia.
• CT pulmonary angiogram revealed diffuse ground-glass opacities.
• Initial investigations including bronchoscopy and bronchoalveolar lavage were inconclusive.

Findings:

• Video-assisted thoracoscopic lung biopsy confirmed extramedullary hematopoiesis within the lung parenchyma.
• This finding represents a rare complication of myeloproliferative disorder.
• The differential diagnosis considered included heart failure, infection, thromboembolism, and drug toxicity.

Implications:

• This case underscores the importance of considering EMH in the differential diagnosis of pulmonary abnormalities in MPD patients.
• Early recognition and diagnosis of pulmonary EMH are crucial for appropriate management.
• Further research into the mechanisms and optimal treatment strategies for pulmonary EMH in MPDs is warranted.