**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Name: Roberta Shcolnik Szor
Institution: Hospital 9 de Julho, DASA
City: Sao Paulo
Country: Brazil

**Main Body of the Abstract**
Background: Light chain amyloidosis can manifest as localized (Loc-AL) or systemic (Sys-AL) disease. Loc-AL is typically indolent, affecting non-vital organs, while Sys-AL is life-threatening, involving organs like heart and kidneys. Although locoregional recurrences of Loc-AL or progression to Sys-AL are described, the reverse is less common. We report a case of Sys-AL relapsing as Loc-AL.
Case: In June 2020, a 63-year-old man presented with dyspnea, fatigue, weight loss, anasarca, and macroglossia starting six months earlier. Cardiac imaging revealed a ventricular septum of 14mm, left ventricular hypertrophy, apical sparing, and late gadolinium enhancement. Stage IIIb / IV Sys-AL was confirmed by the detection of amyloid deposit in the bone marrow (BM), subtyped as lambda by mass spectrometry. Free light chains lambda and kappa measured 807.3 and 13.2 mg/L, BM clonal plasma cells 15%, normal FISH, NTproBNP 9,349 ng/L, Troponin-hs 238 ng/L. Daratumumab-VCD therapy was started, with hematologic CR after 3 cycles. Daratumumab was administered up to 24 cycles as in Andromeda, with sustained CR and best cardiac response observed after 2.5 years (NTproBNP 166 ng/L). One year after Daratumumab discontinuation, a CT scan to evaluate pneumonia detected an axillary mass, confirmed by chest MRI as a 15 x 8.5 x 7.5cm thoracic mass. Biopsy revealed amyloid deposit (ongoing mass spectrometry). No clonal plasma cells were observed in BM, Kappa/lambda ratio and cardiac biomarkers were normal, and Immunofixation showed IgG kappa.
Conclusion: This case represents an unusual presentation of AL amyloidosis, initially manifested as systemic, later relapsing as localized following Daratumumab-VCD therapy.



An Unusual Journey: From Systemic to Localized AL Amyloidosis PA73 (#407)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.