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NJBMS - volume 10 issue 4, April - June 2020

Pages: 134-137

Date of Publication: 15-May-2020


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Non-Hepatosplenic extramedullary hematopoiesis in the background of Acute Myeloblastic Leukemia – A case diagnosed by Fine Needle Aspiration Cytology.

Author: Anbu Lenin Kulandaivel1, Gowri Sankar Ramalingam2, Thamilselvi Ramachandran3

Category: Pathology

Abstract:

Background : Extramedullary hematopoiesis is de?ned as production of progenitors of myeloid and erythroid series outside the bone marrow. EMH can occur in various neoplastic and non-neoplastic disorders which include myeloproliferative neoplasms, hemolytic disorders and chronic anemias. Liver and spleen are considered as two most commonly involved sites in EMH. Although EMH can occur in various disorders, it is rare in acute leukemias. Here we present a case of 52 years old female who was diagnosed to have Non hepatosplenic extramedullary hematopoiesis in cervical lymph node in the background of acute myeloblastic leukemia by ?ne needle aspiration cytology.

Keywords: Acute myeloblastic leukemia, Extramedullary hematopoiesis, Fine needle aspiration cytology, Lymph node.

DOI: //dx.doi.org/10.31975/NJBMS.2020.10403

Full Text:

INTRODUCTION

Extramedullary hematopoiesis is an ectopic hematopoiesis occurring outside the bone marrow. EMH usually occurs when the bone marrow is unable to maintain su?cient red cell mass. It occurs in variety of conditions including fetal development, normal immune response and various haematological pathologies. 1 Expansion of hematopoietic space outside the bone marrow has been observed in many disorders including thalassemia, sickle cell anemia and ITP. [2]EMH may occasionally occur in the lymph nodes in patients with hematopoietic disorders like myeloproliferative neoplasms. Here we are reporting a case of nodal extramedullary hematopoiesis for its rare association with Acute myeloblastic leukemia.

CASE REPORT

A 52 year old female was admitted in the casualty with the complaints of easy fatiguability for 15 days. She had a past history of chronic anaemia which was treated by blood transfusion on and o?. Clinical examination showed no organomegaly. There were few enlarged lymph nodes in the left cervical region with largest node measuring 1cm in diameter. Complete haemogram was done and she had haemoglobin of 5gm/dl, Total WBC count was 90,000cells/ uL, Platelet count was 30,000cells/uL.

Peripheral smear stained with leishman stain showed microcytic hypochromic anaemia, marked leucocytosis with 90% of blast cells and thrombocytopenia.

Blast cells size were 3-5 times that of small lymphocytes with scanty eosinophilic cytoplasm with faint staining ?ne eosinophilic granules, large nucleus with open chromatin showing 1-2 prominent nucleoli [Fig.1a]. Few blast cells showed Auer rod [Fig.1b] and hence diagnosis of ACUTE LEUKEMIA MORPHOLOGICALLY AML

was made and bone marrow examination followed by immunophenotyping by ?ow cytometry was suggested. As patient had lymphadenopathy FNAC was done from largest cervical lymph node. FNAC smears were cellular and showed admixture of erythroid and myeloid precursors, megakaryocytes and lymphoid cells in varying stages of maturation [Fig.1c & 1d]. Blast cells were not increased in number and hence diagnosis of EXTRAMEDULLARY HEMATOPOIESIS was made. However excision of lymph node was also suggested. As patient was not willing Bone marrow examination, Flow cytometry and lymph node excision were not done.

DISCUSSION

Extramedullary hematopoiesis is characterised by the formation and development of blood cells external to the bone marrow medullary spaces. In response to reduced red cell numbers, there will be induction of homeostatic mechanism which increases the red cell production through the synthesis of erythropoietin. 3 EMH occurs either actively or passively secondary to the changes in the hematopoietic environment. Fetal hematopoiesis and EMH that occurs secondary to infections are considered active whereas EMH which occurs secondary to bone marrow failure is considered passive. EMH often involve liver, spleen and lymph node and less frequently other organs such as kidney, retroperitoneum and lungs. 4 Many theories concerned with EMH have been proposed including extrusion of marrow cells consequent to marrow ?brosis, reactivation of hematopoiesis at the site of fetal hematopoiesis such as liver and spleen and embolisation of circulating hematopoietic cells to various organs.5 EMH is usually a microscopic ?nding but can simulate various non neoplastic and neoplastic condition when it presents as mass forming lesion especially in organ like lymph node. Also large cells like megakaryocytes can mimic malignant cells if EMH is not considered. 6 Hence EMH should always be considered in the di?erential diagnosis of the patient with haematological and non haematological disorders.

CONCLUSION

Though liver and spleen are the frequent sites for extramedullary hematopoiesis, it can occur as lymphadenopathy in the background of acute leukemias. Di?erentiating EMH presenting as mass forming lesion associated with or without haematological disorder is crucial for patient management. Fine needle aspiration cytology of lymph node may help in rapid diagnosis because of good cytomorphological details and hence should always be given prime importance.

FINANCIAL SUPPORTAND SPONSORSHIP : Nil.

CONFLICTS OF INTEREST : There are no con?icts of interest.

References:

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