P1256 - Gastrointestinal Amyloidosis Uncovered From Newly Diagnosed Multiple Myeloma

Aumi Brahmbhatt, MD¹, Anthony Sayoc, MD², Rand Hindosh, MD^2
1St. Luke's University Health Network, Anderson Campus, Easton, PA; ²St. Luke's University Health Network, Easton, PA

Introduction: Amyloid light chain (AL) Amyloidosis is an infiltrative condition caused by an excess of Ig light chain produced by plasma cell clonal population in the bone marrow. The plasma cell burden is typically low although it can occur in association with multiple myeloma in 10-15% of patients. Presentation can be variable of which gastrointestinal (GI) amyloidosis presents in only 1-8% of patients.

Case Description/Methods: A 61-year-old woman initially presented with postprandial generalized abdominal pain associated with nausea, dysphagia, and constipation. Poor appetite due to postprandial abdominal discomfort caused a 20 lb weight loss over a one-month period. She was initially treated with proton pump inhibitors and sucralfate with minimal improvement. On further investigation of the patient’s medical history, she was recently diagnosed with multiple myeloma by bone marrow biopsy showing Kappa restricted plasma cells (12% by CD138 immunostaining) and was receiving lenalidomide, which was started 2 months prior to the onset of symptoms. Given the history of multiple myeloma and significant weight loss, the patient was further evaluated for possible amyloidosis. She underwent an esophagogastroduodenoscopy and colonoscopy with cecal and random colon biopsies, and a concurrent abdominal fat pad biopsy was performed. Congo red staining of both cecal and random colon biopsies revealed green birefringence under polarized light confirming the diagnosis of ALamyloidosis. She was maintained on lenalidomide and was seen one month later with significant clinical improvement. Moreover, a decrease in the free light chain ratio was noted.

Discussion: The co-existence of myeloma with focal amyloidosis is extremely uncommon in the medical literature. AL amyloidosis is a rare disease with notable delays in diagnosis resulting in poor outcome. Furthermore, GI involvement in AL amyloidosis is unusual, and diagnosis is further delayed due to vague presentation in the absence of systemic involvement. In our case, a high suspicion secondary to the underlying multiple myeloma led to early diagnosis and treatment along with an improved outcome. Therefore, the underdiagnosed association between AL amyloidosis and multiple myeloma in order to facilitate early diagnosis and treatment is encouraged. We present a case of multiple myeloma and new nonspecific GI symptoms leading to diagnosis of AL GI amyloidosis.


Disclosures:


Aumi Brahmbhatt, MD¹, Anthony Sayoc, MD², Rand Hindosh, MD². P1256 - Gastrointestinal Amyloidosis Uncovered From Newly Diagnosed Multiple Myeloma, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.