P1351 - Solitary Gastric Plasmacytoma: A Rare Challenging Case of Upper GI Bleed

Sunday, October 22, 2023

3:30 PM – 7:00 PM PT

Location: Exhibit Hall

Has Audio

Presenting Author(s)

YS

Yash R. Shah, MD

Trinity Health Oakland/Wayne State University
Pontiac, MI

Yash R. Shah, MD¹, Romina Nomigolzar, ², Dushyant Singh. Dahiya, MD³, Pritha Chitagi, MD², Sri Yadlapalli, MD², Sherwin Imlay, MD²
¹Trinity Health Oakland/Wayne State University, Pontiac, MI; ²Trinity Health Oakland, Pontiac, MI; ³University of Kansas School of Medicine, Kansas City, KS

Introduction: Extramedullary plasmacytomas (EPs) are tumors composed of a monoclonal population of plasma cells that arise in extraosseous tissues without radiological or pathological evidence of plasma cell myeloma. Primary gastric plasmacytoma (GP) represents less than 2% of EPs. Pathological examination is helpful in establishing a diagnosis; however, it can be challenging to make a diagnosis due to overlapping features with plasmablastic lymphoma (PBL). We present this case due to its rarity, challenging diagnosis, and to increase awareness of the entity.

Case Description/Methods: A 51-year-old woman with DM and a 45-pack-year smoking history presented with epigastric pain, fatigue, melena, and weight loss. On arrival, the patient was hypotensive and tachycardic. Positive physical exam findings were midline abdominal tenderness and pallor. Lab work showed iron deficiency anemia (Table 1). CT abdo/pelvis w/ contrast showed irregular mass-like wall thickening (6.9 cm) of the proximal stomach, abutment of the spleen, left hepatic lobe, and hemidiaphragm. EGD on three different occasions showed a large, fungating, non-bleeding mass of 4.5 cm in the gastric cardia and fundus (Figure 1). Gastric biopsy results were inconclusive all three times. Exploratory laparotomy revealed a large mass encasing the gastric cardia and GE junction, spleen, and left lobe of the liver, fixed around the aorta, and challenging to excise due to adherence to surrounding viscera.

Histopathology, FISH, and cytogenetics at our institution from the surgical biopsy was suggestive of PBL (Table 1). Pathology reevaluation and additional work-up including serum immunofixation electrophoresis at a tertiary center showed IgA lambda gammopathy with a M-protein of 1.1 g/dL (Table 1) consistent with solitary gastric plasmacytoma. PET scan showed hypermetabolic activity in the stomach body, fundus, and spleen. Bone marrow biopsy was negative for myeloma. She was treated with a total of 35 grays definitive radiation to the stomach, and tolerated treatment without complications. An increase in hemoglobin and clinical improvements were noted. Follow-up PET scan scheduled in 6 months.

Discussion: The levels of IgA and plasma light chains play a role in differentiating PBL and solitary GP. The plasma cells are typically positive for IgA and may express kappa or lambda light chains in GP compared to PBL. The patient responded well to less aggressive radiotherapy for EP as compared to high dose chemotherapy for PBL further confirming the diagnosis.

Figure: Figure 1: A large fungating and ulcerating mass with a stigmata of recent bleeding in the cardia

Parameter	Initial Values	Post-Radiation	Reference
Hematology Work-up
Red Blood Cells	2.16	4.69	3.8-5.3 M/mcL
Hemoglobin	3.9	14.1	12-16 g/dL
Hematocrit	15.3	44.2	35-46%
MCV	70.8	94.2	80-99 FL
White Blood Cells	9.3	9.4	3.7-11 K/mcL
Platelets	419	290	150-450 K/mcL
Nucleated RBC	1.2	0	< 0.2%
Iron	< 10	75	50-212 mcg/dL
Transferrin	318	-	203-362 mg/dL
Ferritin	73	337.6	7-271 ng/mL
TIBC	445	331	250-450 mcg/dL
Calcium	8.7	-	8.6-10.3 mg/dL
Creatinine	0.64	-	0.6-1.2 mg/dL
BUN	9	-	7-25 mg/dL
FOBT	Positive	-	Negative
Myeloma Work-up at Tertiary center
IgA	1399	157	40-350 mg/dL
Lambda Free Light Chain	199.61	4.58	0.57-2.63 mg/dL
Kappa Free Light Chain	2.55	4.81	0.33-1.94 mg/dL
Kappa/Lambda FLC ratio	0.01	1.05	0.26-1.65
HIV 1 & 2 Ab/Ag	Non-reactive	-	Non-reactive
CMV qPCR	Not Detected	-	Non Detected
EBV DNA	Not Detected	-	Not Detected
HHV 8 qPCR	Not Detected	-	Not Detected
Gastric Tissue Biopsy w/ Immunohistochemical Stain and Flow Cytometry
Multiple fragments of tissue infiltrated by an atypical population of large cells with round, irregular nuclear contours, open chromatin, and basophilic cytoplasm, with occasional large vacuoles, frequent mitoses, apoptotic debris. Lambda restricted plasma cells with +ve expression for CD38, CD56, and CD45 consistent with plasma cell neoplasm Ki-67 Proliferation Index: 60-70%
FISH Cytogenetics
Gain(s) of MYC/8q; Negative for MYC rearrangement
Bone Marrow Biopsy and Blood Leukemia/Lymphoma Flow Cytometry
Hypercellular bone marrow with maturing trilineage hematopoiesis. No definitive evidence of plasma cell neoplasm

Table: Table 1: Pertinent Positive Laboratory Findings

Disclosures:

Yash Shah indicated no relevant financial relationships.

Romina Nomigolzar indicated no relevant financial relationships.

Dushyant Dahiya indicated no relevant financial relationships.

Pritha Chitagi indicated no relevant financial relationships.

Sri Yadlapalli indicated no relevant financial relationships.

Sherwin Imlay indicated no relevant financial relationships.

Yash R. Shah, MD¹, Romina Nomigolzar, ², Dushyant Singh. Dahiya, MD³, Pritha Chitagi, MD², Sri Yadlapalli, MD², Sherwin Imlay, MD². P1351 - Solitary Gastric Plasmacytoma: A Rare Challenging Case of Upper GI Bleed, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.