{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T03:11:15Z","timestamp":1780629075793,"version":"3.54.1"},"reference-count":6,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T00:00:00Z","timestamp":1619049600000},"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>Early detection of immune-related adverse events (irAEs) with immune checkpoint inhibitors (ICIs) is crucial, particularly when these are likely to mimic tumor progression, as well as sarcoid-like reactions. Here, we report the case of a 68-year woman, with a history of four primary cutaneous melanomas (thickest lesion with BRAF mutation removed from the left axilla 2 years before), who was diagnosed with BRAF V600E-mutant metastatic melanoma and treated by ICI targeting the PD-1 receptor. Follow-up whole-body positron emission tomography\/computed tomography (PET\/CT) using 18F-fluorodeoxyglucose ([18F]-FDG) was performed at 15 months, and FDG-avid subcutaneous nodules on her legs were detected. A biopsy from a lesion on her right leg was obtained, and histology strongly suggested erythema nodosum. Given the isolated nature of these lesions, the normal serum Angiotensin-Converting Enzyme and the context of ICI, an immune-related sarcoid-like reaction was retained as the most likely diagnosis. Recent literature in immune-oncology suggests that erythema nodosum could be directly related to ICI(s). Although erythema nodosum is a rare occurrence with imaging features overlapping with malignancy, it should be considered in the differential diagnosis of suspicious in-transit metastasis, especially when the patient is treated with ICIs and when lesions follow a bilateral distribution. In conclusion, nuclear medicine physicians should keep in mind this irAE when interpreting PET\/CT scans in clinical practice in order to avoid false-positive findings.<\/jats:p>","DOI":"10.3390\/diagnostics11050747","type":"journal-article","created":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T04:20:17Z","timestamp":1619065217000},"page":"747","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Immune-Related Erythema Nodosum Mimicking in Transit Melanoma Metastasis on [18F]-FDG PET\/CT"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2584-5478","authenticated-orcid":false,"given":"Romain-David","family":"Seban","sequence":"first","affiliation":[{"name":"Department of Nuclear Medicine, Institut Curie, 92210 Saint-Cloud, France"},{"name":"Laboratoire d\u2019Imagerie Translationnelle en Oncologie, Inserm, Institut Curie, 91401 Orsay, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Camille","family":"Vermersch","sequence":"additional","affiliation":[{"name":"Department of Dermatology, H\u00f4pital Ambroise Par\u00e9, AP-HP, 92100 Boulogne-Billancourt, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laurence","family":"Champion","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Institut Curie, 92210 Saint-Cloud, France"},{"name":"Laboratoire d\u2019Imagerie Translationnelle en Oncologie, Inserm, Institut Curie, 91401 Orsay, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benjamin","family":"Bonsang","sequence":"additional","affiliation":[{"name":"Department of Pathology, H\u00f4pital Ambroise Par\u00e9, AP-HP, 92100 Boulogne-Billancourt, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0777-600X","authenticated-orcid":false,"given":"Anissa","family":"Roger","sequence":"additional","affiliation":[{"name":"Department of Dermatology, H\u00f4pital Ambroise Par\u00e9, AP-HP, 92100 Boulogne-Billancourt, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jerome","family":"Ghidaglia","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Institut Curie, 92210 Saint-Cloud, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1186\/s40425-018-0372-4","article-title":"Thoracic and cutaneous sarcoid-like reaction associated with anti-PD-1 therapy: Longitudinal monitoring of PD-1 and PD-L1 expression after stopping treatment","volume":"6","author":"Paolini","year":"2018","journal-title":"J. Immunother. Cancer"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1111\/ajd.12970","article-title":"A case of erythema nodosum-like panniculitis induced by nivolumab in a patient with oesophageal cancer","volume":"60","author":"Choi","year":"2019","journal-title":"Australas. J. Dermatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"627","DOI":"10.1177\/1203475418776934","article-title":"Erythema Nodosum as the Initial Presentation of Nivolumab-Induced Sarcoidosis-Like Reaction","volume":"22","author":"Laroche","year":"2018","journal-title":"J. Cutan. Med. Surg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1097\/RLU.0000000000001448","article-title":"Erythema Nodosum\u2013Like Panniculitis as a False-Positive 18F-FDG PET\/CT in Advanced Melanoma Treated with Dabrafenib and Trametinib","volume":"42","author":"Quirce","year":"2017","journal-title":"Clin. Nucl. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1186\/s40425-018-0323-0","article-title":"Granulomatous\/sarcoid-like lesions associated with checkpoint inhibitors: A marker of therapy response in a subset of melanoma patients","volume":"6","author":"Tetzlaff","year":"2018","journal-title":"J. Immunother. Cancer"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1080","DOI":"10.1111\/cup.13044","article-title":"Erythema nodosum-like panniculitis mimicking disease recurrence: A novel toxicity from immune checkpoint blockade therapy-Report of 2 patients","volume":"44","author":"Tetzlaff","year":"2017","journal-title":"J. Cutan. Pathol."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/11\/5\/747\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:51:09Z","timestamp":1760161869000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/11\/5\/747"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,22]]},"references-count":6,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["diagnostics11050747"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics11050747","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,22]]}}}