**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.**
Arianne Clare Agdamag, Cleveland Clinic Foundation, Cleveland, OH

**Main Body of the Abstract**
A 51-year-old Caucasian male with history of carpal tunnel syndrome, spinal stenosis and bicep tendon rupture initially presented with shortness of breath. TTE demonstrated normal LVEF and severe concentric LVH (IVSd 1.92cm, PWd 1.9cm) raising suspicion for amyloidosis. Technetium99m pyrophosphate (99mTc-PYP) scan showed a semi-quantitative visual score of grade 0 and no uptake on SPECT/CT. Cardiac MRI exhibited diffuse patchy mid-wall late gadolinium enhancement and elevated extracellular volume (62%). Laboratory work-up included Hs-TNT 21ng/L, NT proBNP 1711pg/mL, kappa light chain 18.8mg/L, lambda light chain 219.2mg/L, FLC difference 199.8mg/L, K/L ratio 0.09 and immunofixation revealed a poorly defined region of restricted mobility in the lambda lane. Bone marrow biopsy (BMx) showed a lambda restricted plasma cell neoplasm representing 10% of marrow cellularity with no amyloid deposition. Fluorescence in situ hybridization results were normal. Endomyocardial biopsy (EMBx) demonstrated amorphous material strongly positive with thioflavin-S staining and immunohistochemistry observed amyloid deposits positive for lambda light chains. Laser capture microdissection coupled to mass spectrometry (LCM-MS)showed equal abundance of lambda immunoglobulin light chains and transthyretin deposition. Genetic testing was negative. He received daratumumab, cyclophosphamide, bortezomib, and dexamethasone and was eventually started on tafamidis.
This case highlights a rare but clinically relevant concurrent presence of two different types of amyloidosis. Proceeding with simultaneous 99mTc-PYP and hematologic work-up is highly recommended when amyloid is suspected. If initial work-up is suggestive of both AL and ATTR amyloidosis, histopathological investigation with EMBx and BMx is warranted. A thorough and complete diagnostic work-up is needed to ensure appropriate management.



**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.**
Arianne Clare Agdamag, Cleveland Clinic Foundation, Cleveland, OH

**Main Body of the Abstract**
A 51-year-old Caucasian male with history of carpal tunnel syndrome, spinal stenosis and bicep tendon rupture initially presented with shortness of breath. TTE demonstrated normal LVEF and severe concentric LVH (IVSd 1.92cm, PWd 1.9cm) raising suspicion for amyloidosis. Technetium99m pyrophosphate (99mTc-PYP) scan showed a semi-quantitative visual score of grade 0 and no uptake on SPECT/CT. Cardiac MRI exhibited diffuse patchy mid-wall late gadolinium enhancement and elevated extracellular volume (62%). Laboratory work-up included Hs-TNT 21ng/L, NT proBNP 1711pg/mL, kappa light chain 18.8mg/L, lambda light chain 219.2mg/L, FLC difference 199.8mg/L, K/L ratio 0.09 and immunofixation revealed a poorly defined region of restricted mobility in the lambda lane. Bone marrow biopsy (BMx) showed a lambda restricted plasma cell neoplasm representing 10% of marrow cellularity with no amyloid deposition. Fluorescence in situ hybridization results were normal. Endomyocardial biopsy (EMBx) demonstrated amorphous material strongly positive with thioflavin-S staining and immunohistochemistry observed amyloid deposits positive for lambda light chains. Laser capture **microdissection** coupled to **mass** **spectrometry** (LCM-MS)showed equal abundance of lambda immunoglobulin light chains and transthyretin deposition. Genetic testing was negative. He received daratumumab, cyclophosphamide, bortezomib, and dexamethasone and was eventually started on tafamidis.
This case highlights a rare but clinically relevant concurrent presence of two different types of amyloidosis. Proceeding with simultaneous 99mTc-PYP and hematologic work-up is highly recommended when amyloid is suspected. If initial work-up is suggestive of both AL and ATTR amyloidosis, histopathological investigation with EMBx and BMx is warranted. A thorough and complete diagnostic work-up is needed to ensure appropriate management.



Double Trouble: A case of biopsy proven ATTR and AL cardiac amyloid PA89 (#67)

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.