Renal Peripelvic Extramedullary Haematopoiesis in Myelofibrosis: A Rare Imaging Pitfall Assessed by Multimodality Nuclear Imaging
Year: 2026
Type: article
Study design: Case Report
Abstract: Extra-medullary haematopoiesis (EMH) refers to haematopoietic proliferation outside the bone marrow, most often arising as a compensatory response to ineffective marrow function in chronic anaemias and myeloid neoplasms, particularly myelofibrosis and other myeloproliferative neoplasms. While the liver and spleen are typical sites, mass-forming EMH in non-reticuloendothelial organs is rare; renal involvement is particularly uncommon and may closely mimic infiltrative malignancy or infection on cross-sectional imaging. We report a 35-year-old woman who presented with asthenia, progressive weight loss and intermittent fever. Previous bone-marrow biopsy had demonstrated early myelofibrosis. Contrast-enhanced thoraco-abdominopelvic CT showed bilateral thoracic paravertebral and presacral soft-tissue masses and left peripelvic/pelvicalyceal infiltration, raising concern for malignancy or infection. Whole-body [18F]-FDG-PET/CT revealed only faint (low-grade) hypermetabolism within the paravertebral and presacral lesions, and no convincing focal hypermetabolism within the renal lesion, whose assessment was limited by urinary tracer activity. Given the haemorrhagic risk of renal biopsy in a cytopenic patient, technetium-99m sulphur colloid scintigraphy with SPECT/CT demonstrated tracer uptake within all lesions, confirming multifocal EMH. This case highlights renal peripelvic EMH as a rare malignancy mimic for which [18F]-FDG-PET/CT may be non-diagnostic, and supports sulphur colloid SPECT/CT as a robust, non-invasive alternative when tissue sampling is hazardous.
Source: Diagnostics
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7141575796