{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T16:10:26Z","timestamp":1770048626915,"version":"3.49.0"},"reference-count":6,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T00:00:00Z","timestamp":1769904000000},"content-version":"vor","delay-in-days":31,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Case Reports in Hematology"],"published-print":{"date-parts":[[2026,1]]},"abstract":"<jats:p>A 56\u2010year\u2010old woman with a history of C4\u2013C5 myelomeningocele repair as a newborn and cervical syringomyelia presented with one week of rapidly worsening bilateral lower extremity weakness and numbness, saddle anesthesia, and bladder incontinence. MRI of the entire spine revealed a 1.5\u2009\u00d7\u20090.5\u2009cm homogenously enhancing intramedullary lesion at T7\u2013T8 with associated cord edema and rostral syrinx formation. MRI of the brain and FDG PET\u2013CT scan were unremarkable. She was taken to the operating room for a T6\u2013T8 laminectomy and biopsy. H&amp;E staining revealed a relatively dense mononuclear\u2010cell infiltrate, which comprised numerous medium\u2010sized cells with round, irregular, or reniform nuclei, slightly dispersed chromatin, and relatively abundant eosinophilic, and occasionally, somewhat vacuolated cytoplasm. Immunohistochemical staining was strongly positive for CD163, PU.1, CD68, and ALK. FISH studies demonstrated ALK rearrangement in 70% of nuclei. Next\u2010generation sequencing including both DNA and RNA testing on a formalin\u2010fixed, paraffin\u2010embedded tissue sample detected a KIF5B\/ALK gene fusion. She received radiotherapy with 2000\u2009cGY in 200\u2009cGy fractions to T6\u2013T9 with no change in lesional size or enhancement. She was started on the ALK inhibitor alectinib. Subsequent MRI showed a complete response. She has had no evidence of disease recurrence on alectinib for 18\u2009months. ALK\u2010positive histiocytosis is a recently described distinct clinicopathologic entity. Our case is notable for older age at diagnosis, isolated intramedullary involvement, and radioresistance but later marked targeted\u2010therapy response, thus furthering the understanding of the spectrum of ALK\u2010positive histiocytosis biology.<\/jats:p>","DOI":"10.1155\/crh\/1712521","type":"journal-article","created":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T05:07:56Z","timestamp":1770008876000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Radioresistant but Alectinib\u2010Responsive Isolated Intramedullary ALK\u2010Positive Histiocytosis"],"prefix":"10.1155","volume":"2026","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6705-1118","authenticated-orcid":false,"given":"Joshua Van","family":"Allen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Raggay","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brendan","family":"Killory","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"DiGiuseppe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mark","family":"Dailey","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2026,2]]},"reference":[{"key":"e_1_2_9_1_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(21)00311-1"},{"key":"e_1_2_9_2_2","doi-asserted-by":"publisher","DOI":"10.1007\/s12033-024-01072-2"},{"key":"e_1_2_9_3_2","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2021013338"},{"key":"e_1_2_9_4_2","doi-asserted-by":"publisher","DOI":"10.1186\/s13023-023-02649-x"},{"key":"e_1_2_9_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41379-018-0168-6"},{"key":"e_1_2_9_6_2","doi-asserted-by":"publisher","DOI":"10.1634\/theoncologist.2016-0488"}],"container-title":["Case Reports in Hematology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1155\/crh\/1712521","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1155\/crh\/1712521","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1155\/crh\/1712521","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T05:07:57Z","timestamp":1770008877000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1155\/crh\/1712521"}},"subtitle":[],"editor":[{"given":"Carlos","family":"Cruz-Montecinos","sequence":"additional","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2026,1]]},"references-count":6,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2026,1]]}},"alternative-id":["10.1155\/crh\/1712521"],"URL":"https:\/\/doi.org\/10.1155\/crh\/1712521","archive":["Portico"],"relation":{},"ISSN":["2090-6560","2090-6579"],"issn-type":[{"value":"2090-6560","type":"print"},{"value":"2090-6579","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1]]},"assertion":[{"value":"2025-02-22","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-01-20","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-02-01","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"1712521"}}