Related Experiment Video
Updated: Jan 8, 2026

Use of Hematopoietic Stem Cell Transplantation to Assess the Origin of Myelodysplastic Syndrome
Published on: October 3, 2018
A Massive Haemothorax Due to Pleural Extramedullary Haematopoiesis in a Patient With Myelodysplastic
Maha Theeb1, Sarah Idris1, Michael Sheaff2
1Department of Haemato-Oncology, St Bartholomew's Hospital, Barts Health NHS Trust, London, GBR.
Extramedullary haematopoiesis (EMH) refers to blood cell production outside the bone marrow, typically in reticuloendothelial organs such as spleen, liver, and lymph nodes, as a compensatory response to haematopoietic stress. We describe a rare case of recurrent haemothorax caused by pleural EMH in a female patient in her 60s with myelodysplastic/myeloproliferative neoplasm (MDS/MPN) not otherwise specified (NOS). She had recurrent presentations with transfusion-dependent anaemia, fevers, splenomegaly, and bone marrow morphology consistent with MDS/MPN. Over the course of her disease, she developed recurrent left-sided pleural effusions and haemothorax, initially managed with repeated drainage. Video-assisted thoracoscopic surgery (VATS) with pleural biopsy confirmed EMH with infiltration by myeloid precursors and megakaryocytes. Despite azacitidine therapy and supportive management, her condition progressed to multi-organ failure and death. The case highlights an unusual site of EMH and emphasises the need to consider EMH in the differential diagnosis of haemorrhagic pleural effusions in patients with malignant haematological disorders.
Extramedullary haematopoiesis (EMH) refers to blood cell production outside the bone marrow, typically in reticuloendothelial organs such as spleen, liver, and lymph nodes, as a compensatory response to haematopoietic stress. We describe a rare case of recurrent haemothorax caused by pleural EMH in a female patient in her 60s with myelodysplastic/myeloproliferative neoplasm (MDS/MPN) not otherwise specified (NOS). She had recurrent presentations with transfusion-dependent anaemia, fevers, splenomegaly, and bone marrow morphology consistent with MDS/MPN. Over the course of her disease, she developed recurrent left-sided pleural effusions and haemothorax, initially managed with repeated drainage. Video-assisted thoracoscopic surgery (VATS) with pleural biopsy confirmed EMH with infiltration by myeloid precursors and megakaryocytes. Despite azacitidine therapy and supportive management, her condition progressed to multi-organ failure and death. The case highlights an unusual site of EMH and emphasises the need to consider EMH in the differential diagnosis of haemorrhagic pleural effusions in patients with malignant haematological disorders.
Related Concept Videos
Pleural Effusion I: Introduction
There are two main types of pleural effusion: transudative and exudative. They are differentiated using Light's...
Pneumothorax-II
Clinical Manifestations:
Pleural Effusion II: Symptoms and Management
A pleural effusion is the abnormal collection of fluid between the parietal and visceral pleura layers of tissue that form the lining of the lungs and chest cavity. It can occur independently or due to surrounding parenchymal diseases, such as infection, malignancy, or inflammatory conditions.
Clinical Manifestations:
Disorders of Erythrocytes
Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...
Pulmonary Embolism II: Diagnostic Studies and Interprofessional Care
Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:

