P3380 - A Rare Case of Extramedullary Plasmacytoma of the Stomach

Ahmad Alomari, MD¹, Khaled Al Smadi, MD², Hasan Sqour, MD³, Ismail Althunibat, MD⁴, Ahmad Hushki, MBBCh^5
1Henry Ford Hospital, Detroit, MI; ²University of California Riverside School of Medicine, San Bernardino, CA; ³Ascension Saint Joseph Hospital, Chicago, IL; ⁴Saint Michael's Medical Center, Newark, NJ; ⁵King Hussein Cancer Center, Jubeiha, 'Amman, Jordan

Introduction: Plasma cell neoplasms (PCNs) are a group of disorders including multiple myeloma (MM), solitary plasmacytoma of bone (SPB) and primary extramedullary plasmacytoma (EMP). These disorders are characterized by monoclonal secretion of immunoglobulins from differentiated B lymphocytic cells. Most EMP cases occur in the head and neck with relatively rare presentation in other parts of the body. Herein, we introduce a case of EMP with a gastric mass presenting with upper gastrointestinal tract bleeding.

Case Description/Methods: A 55-year-old gentleman with a history of Multiple Myeloma in clinical remission after four cycles of Bortezomib, Thalidomide, and Dexamethasone (VTD) and autologous stem cell transplantation. The patient was presented with two weeks of melena and hemoglobin drop. Endoscopic gastroduodenoscopy (EGD) showed a 4 x 4 cm mass with deep necrotic central ulceration at the anterior wall of the proximal corpus without active bleeding (Figure 1). Accordingly, a biopsy was collected, and pathology report showed involvement by CD138 positive poorly differentiated plasma cells, that are restricted for Lambda light chain and is consistent with the diagnosis of extramedullary gastric plasmacytoma for which he received chemotherapy, unfortunately the patient developed sepsis and multiorgan failure, after his first cycle and his admission ended up by death.

Discussion: MM with EMP is a rare variant of PCNs where tumors composed of plasma cells arise outside the bone marrow. The most common sites for EMP include the respiratory tract, urinary bladder, brain, thyroid, and skin. EMP involvement of the gastrointestinal tract is indeed a rare occurrence representing < 1% of MM cases. Intraabdominal EMPs usually have a relatively slow-growing and indolent course with nonspecific symptoms like abdominal pain, melena, hematochezia, intussusception or localized perforation. The specific anatomical location of the EMP plays a role in determining the method used for obtaining a formal tissue diagnosis such as gastroscopic biopsy for gastric EMPs. Multiple myeloma with EMP presents a unique and challenging scenario lacking an established treatment consensus and requiring individualized therapy based on each patient’s circumstances. It is important to keep a wide differential diagnosis for gastroenterology bleed especially in patients with complex medical history. This case illustrates the importance of histopathological examination in establishing a definitive diagnosis and guiding management.



Disclosures:


Ahmad Alomari, MD¹, Khaled Al Smadi, MD², Hasan Sqour, MD³, Ismail Althunibat, MD⁴, Ahmad Hushki, MBBCh⁵. P3380 - A Rare Case of Extramedullary Plasmacytoma of the Stomach, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.