{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T11:02:03Z","timestamp":1774868523585,"version":"3.50.1"},"reference-count":13,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T00:00:00Z","timestamp":1774569600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Extramedullary 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, renal involvement remains particularly uncommon and may mimic infiltrative malignancy or infection on cross-sectional imaging. We report a 35-year-old woman with biopsy-proven grade 2 myelofibrosis who presented with constitutional symptoms, namely asthenia, progressive weight loss, and intermittent fever, in the setting of pancytopenia. Contrast-enhanced CT demonstrated bilateral thoracic paravertebral and presacral soft-tissue masses, with left peripelvic\/pelvicalyceal infiltration, raising concern for infiltrative malignancy or infection. [18F]-FDG-PET\/CT showed low-grade uptake in the paravertebral and presacral lesions, while the renal lesion remained indeterminate because of adjacent urinary tracer activity. Given the haemorrhagic risk of renal biopsy in a cytopenic patient, [99mTc]-sulphur colloid scintigraphy with SPECT\/CT was performed and demonstrated concordant tracer uptake in all lesions, supporting multifocal EMH. After disease-directed treatment, follow-up CT at 12 months showed marked regression of the renal and other EMH lesions. This case highlights renal peripelvic EMH as a rare imaging pitfall and underscores the value of multimodality imaging when biopsy is high risk.<\/jats:p>","DOI":"10.3390\/diagnostics16071011","type":"journal-article","created":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T12:45:53Z","timestamp":1774615553000},"page":"1011","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Renal Peripelvic Extramedullary Haematopoiesis in Myelofibrosis: A Rare Imaging Pitfall Assessed by Multimodality Nuclear Imaging"],"prefix":"10.3390","volume":"16","author":[{"given":"Redouane","family":"Soussi","sequence":"first","affiliation":[{"name":"Nuclear Medicine Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-0766-916X","authenticated-orcid":false,"given":"Ayoub","family":"Jaafari","sequence":"additional","affiliation":[{"name":"Nuclear Medicine Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anas","family":"Chbabou","sequence":"additional","affiliation":[{"name":"Radiology Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sara","family":"Zouggari","sequence":"additional","affiliation":[{"name":"Nuclear Medicine Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manar","family":"Zaiter","sequence":"additional","affiliation":[{"name":"Radiology Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tom","family":"Saliba","sequence":"additional","affiliation":[{"name":"Radiology Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patrick","family":"Flamen","sequence":"additional","affiliation":[{"name":"Nuclear Medicine Department, H.U.B Hospital, 1070 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1016\/j.crad.2019.12.016","article-title":"Marrow outside marrow: Imaging of extramedullary haematopoiesis","volume":"75","author":"Malla","year":"2020","journal-title":"Clin. Radiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"807","DOI":"10.1016\/j.crad.2016.05.014","article-title":"Extramedullary haematopoiesis: Radiological imaging features","volume":"71","author":"Roberts","year":"2016","journal-title":"Clin. Radiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1007\/BF01696233","article-title":"Extramedullary hematopoiesis encasing the pelvicalyceal system: CT findings","volume":"71","author":"Gryspeerdt","year":"1995","journal-title":"Ann. Hematol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1159\/000087809","article-title":"Extramedullary hematopoiesis in chronic myelofibrosis encasing the pelvicaliceal system and perirenal spaces: CT findings","volume":"75","author":"Torretta","year":"2005","journal-title":"Urol. Int."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1016\/j.crad.2006.05.013","article-title":"Renal extramedullary haematopoiesis mimicking renal lymphoma on computed tomography","volume":"61","author":"Volchek","year":"2006","journal-title":"Clin. Radiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1093\/ckj\/sfs015","article-title":"Extramedullary haematopoiesis in the kidney","volume":"5","author":"Ricci","year":"2012","journal-title":"Clin. Kidney J."},{"key":"ref_7","unstructured":"Nicolosi, L., Ini, C., Clemenza, M., Palumbo, G.A., Farina, R., Foti, P.V., Palmucci, S., and Basile, A. (2023). Radiological features of renal extramedullary hematopoiesis. ECR 2023; Educational Exhibit, ESR\u2014European Society of Radiology."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1002\/ajh.24616","article-title":"Diffuse pulmonary extramedullary hematopoiesis in myelofibrosis diagnosed with technetium-99m sulfur colloid bone marrow scintigraphy and single photon emission computerized tomography\/CT","volume":"92","author":"Yang","year":"2017","journal-title":"Am. J. Hematol."},{"key":"ref_9","first-page":"234","article-title":"The value of FDG-PET CT scans to evaluate bone marrow in haemato-oncological conditions","volume":"77","author":"Evers","year":"2019","journal-title":"Neth. J. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1007\/s13139-022-00773-3","article-title":"Extramedullary hematopoiesis visualized on FDG-PET\/CT in a patient with beta-thalassemia","volume":"56","author":"Nielsen","year":"2022","journal-title":"Nucl. Med. Mol. Imaging"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2378","DOI":"10.1002\/cam4.835","article-title":"Assessment of sites of marrow and extramedullary hematopoiesis by hybrid imaging in patients with primary myelofibrosis","volume":"5","author":"Morel","year":"2016","journal-title":"Cancer Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1080\/16078454.2021.2009645","article-title":"Updated recommendations on the use of ruxolitinib for the treatment of myelofibrosis","volume":"27","author":"Devos","year":"2022","journal-title":"Hematology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e62","DOI":"10.1016\/S2352-3026(23)00305-8","article-title":"Indication and management of allogeneic haematopoietic stem-cell transplantation in myelofibrosis: Updated recommendations by the EBMT\/ELN International Working Group","volume":"11","author":"Bacigalupo","year":"2024","journal-title":"Lancet Haematol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/7\/1011\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T10:11:15Z","timestamp":1774865475000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/7\/1011"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,27]]},"references-count":13,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["diagnostics16071011"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16071011","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,27]]}}}