Kidney Week

Abstract: SA-PO182

Rare Glomerulopathy Associated with Renal Extramedullary Hematopoiesisin a Patient with Primary Myelofibrosis

Session Information

• Onconephrology: Kidney Outcomes during Cancer Treatment and Nephropathies
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Onconephrology

• 1700 Onconephrology

Authors

• Mesgun, Sami, University Hospitals, Cleveland, Ohio, United States

Sami Mesgun, MD

• Grosser, Daniel, University Hospitals, Cleveland, Ohio, United States

Daniel Grosser, MD

• Oduro, Kwadwo Asare, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, United States

Kwadwo Asare Oduro, MD, PhD

• Wang, Jing, University Hospitals, Cleveland, Ohio, United States

Jing Wang, MD

• Elmi, Adily N., University Hospitals, Cleveland, Ohio, United States

Adily N. Elmi, MD, MPH

• Chang, Richard Y., University Hospitals, Cleveland, Ohio, United States

Richard Y. Chang, MD

• Rashidi, Arash, University Hospitals, Cleveland, Ohio, United States

Arash Rashidi, MD, FASN

Introduction

Primary myelofibrosis (PMF) is a rare form of myeloproliferative neoplasm (MPN) that results in increased megakaryocytes and granulocytes, leading to marrow fibrosis, cytopenia, and splenomegaly due to extramedullary hematopoiesis (EMH). Glomerular involvement is rare and characterized by renal injury and proteinuria. MPN-related glomerulopathy is an underrecognized late complication of MPN.

Case Description

A 75-year-old woman with PMF and CKD presented with AKI and proteinuria. She was previously diagnosed with CALR type-1 myelofibrosis for which she began darbepoetin alfa. She was monitored without immune-modulation therapy.

A kidney biopsy revealed EMH, notably present with atypical megakaryocytes on light microscopy. Interstitial fibrosis was also noted throughout most of the sampled cortex. She was diagnosed with PMF-related glomerulopathy with EMH.

Discussion

PMF findings vary by the phase of the neoplastic process from hypercellular marrow with myeloid predominance to hypocellular marrow with fibrosis and atypical megakaryocytes. Glomerular changes in MPN are sparsely described, with observed lesions possibly linked to the overproduction of cytokines and growth factors by clonal hematopoietic cells. Generally, the presence of EMH within glomerular capillaries, namely megakaryocytes, distinguishes MPN-related glomerulopathy from other glomerulopathies. EMH found in our case argues for direct involvement of the kidney by the neoplastic process.

In sum, patients with PMF should be screened for proteinuria and kidney injury as early as possible, for the presence of renal dysfunction should be concerning for renal EMH and MPN-related glomerular disease.

Figure 1. Kidney biopsy findings: (a) Renal interstitium is prominently infiltrated by hematopoietic elements, including erythroid precursors (red arrow on illustrative cluster), characterized by round hyperchromatic nuclei and eosinophilic to basophilic cytoplasm, and atypical megakaryocytes (blue arrows), characterized by clustering and bulbous hyperchromatic nuclei. Renal proximal tubules are visible at the top and bottom of the image. (b) Megakaryocytes are also found in vascular spaces, highlighted by CD34. (c) Megakaryocytes stain with Factor 8.