P0113 - Atypical, Relapsing Type 1 Autoimmune Pancreatitis in a Patient with Breast Cancer and Rheumatoid Arthritis

Bridget M. Gallagher, MD¹, Tanuj R. Chokshi, DO², Kristaq Koci, DO³, John Diks, MD⁴, Ellen Ginzler, MD, MPH³, Olga Dvorkina, MD³, Shivakumar Vignesh, MD, FACG^4
1SUNY Downstate, Brooklyn, NY; ²State University of New York Downstate University Hospital, Brooklyn, NY; ³State University of New York Downstate Medical Center, Brooklyn, NY; ⁴SUNY Downstate Health Science University, Brooklyn, NY

Introduction: Type 1 autoimmune pancreatitis (AIP) and idiopathic duct-centric chronic pancreatitis (IDCP) are distinct steroid-responsive fibro-inflammatory diseases of the pancreas that share overlapping features and can be difficult to distinguish. Here, we describe an atypical presentation of relapsing type 1 AIP.

Case Description/Methods: 65-year-old female with rheumatoid arthritis (RA) and breast cancer status post lumpectomy, radiation, and aromatase inhibition followed by Rheumatology. Therapy for RA was limited by medication intolerance, insurance coverage, and allergies. Adalimumab therapy led to RA remission but was complicated by elevated liver transaminases (LT). Evaluation by Gastroenterology was significant for a pancreatic head lesion and concentric CBD wall thickening. Absence of biliary strictures and jaundice was atypical. A timeline of investigations with findings can be found on Table 1.



IgG4 levels were elevated and glucocorticoid therapy for suspected type 1 AIP was initiated after considering results of imaging and biopsies. Repeat imaging 1 year later revealed reduction in pancreatic lesion size. Labs demonstrated resolution of LT abnormalities and significant reductions in IgG4, ESR, and CRP. HISORt Criteria Diagnostic Group C were fulfilled suggestive of type 1 AIP. Glucocorticoid therapy was continued for 6 weeks. Repeat labs revealed stable findings. MRCP demonstrated a new pancreatic body lesion. Adalimumab was discontinued and Abatacept was initiated.

Discussion: Breast cancer may induce serum autoantibodies producing paraneoplastic AIP. Anastrozole has been implicated in drug-induced autoimmune subacute cutaneous lupus erythematosus. CT chest from 2007 demonstrated normal visualized portions of the pancreas. Two years after immunomodulator initiation, our patient developed LT abnormalities and pancreatic lesions. We hypothesize that her breast cancer, Anastrozole, and immunomodulator exposure may have contributed to the development of atypical AIP.



Regarding management, Yamamoto et al. demonstrated reductions in pancreatic lesion size, IgG4, and RF levels with Abatacept and Prednisolone administration. Hart et al. showed 83% of patients with treatment resistance experienced complete remission without relapses on maintenance therapy when on Rituximab (RTX). Given new pancreatic lesions, Adalimumab was discontinued and a trial of Abatacept was initiated. We are awaiting response to Abatacept before initiating RTX, given greater magnitude of immunosuppressive effects.

Investigation	Findings
Abdominal ultrasound (05/2019)	Diffusely coarsened hepatic parenchymal echogenicity. Hypoechoic pancreatic head mass No dilatation of the intra- or extrahepatic biliary tree
Pancreatic CT protocol (07/2019)	Hypovascular 3.5 x 3.2 x 4.1 cm mass in the head of the pancreas Pancreatic duct distention to 5 mm distal to the mass Atrophic pancreatic tail
EUS-FNB (10/2019)	Hypoechoic, heterogenous 4.2 x 3.5 cm pancreatic lesion in the head and neck extending to the proximal body with ill-defined margins Loss of the echoplane between the lesion, the portal vein, and SMV for 23 mm concerning for invasion. SMA not visualized clearly Multiple subcentimeter peripancreatic nodes with equivocal features of malignancy
EUS-FNB (11/2019)	Concentric CBD wall thickening. CBD measured 3.5 mm at distal third, 3.9 at the middle third, and 5 mm at the porta hepatis 25.6 x 37.1 mm heterogenous, hypoechoic mass in the areas of the pancreatic head, neck, and proximal body MPD coursing through the lesion nonobstructed
Pancreatic CT protocol (02/2020)	3 cm slightly low attenuation soft tissue mass in region of head of pancreas No pancreatic duct dilatation Mass contacts the portal vein and superior mesenteric vein but does not occlude it
MRCP (10/2020)	3.5 cm hypovascular lesion in the head of the pancreas A second 1.9 cm lesion in the body of the pancreas Pancreatic duct tapers to a close around the pancreatic head mass, without distal pancreatic duct dilatation Remaining pancreatic tissue is atrophic Pancreatic head mass abuts the SMV without invasion or occlusion No lymphadenopathy
EUS-FNB (01/2021)	Hypoechoic lesion measuring 21 x 14 mm was visualized in the body of the pancreas MPD coursed non-obstructed through the lesion 3 x 3.5 cm hypoechoic, heterogenous lesion with ill-defined margins was identified in the head of the pancreas
Results from Pathology of biopsies from EUS-FNBs (10/2019, 11/2019, and 01/2021)	Dense fibrous tissue with lymphoplasmacytic infiltrates (CD3, CD20, CD138 positive) which was negative for epithelial markers (AE1/AE3, CAM5 negative)

Table: Table 1: Timeline of Investigations and Findings


Disclosures:
Bridget Gallagher indicated no relevant financial relationships.
Tanuj Chokshi indicated no relevant financial relationships.
Kristaq Koci indicated no relevant financial relationships.
John Diks indicated no relevant financial relationships.
Ellen Ginzler indicated no relevant financial relationships.
Olga Dvorkina indicated no relevant financial relationships.
Shivakumar Vignesh indicated no relevant financial relationships.


Bridget M. Gallagher, MD¹, Tanuj R. Chokshi, DO², Kristaq Koci, DO³, John Diks, MD⁴, Ellen Ginzler, MD, MPH³, Olga Dvorkina, MD³, Shivakumar Vignesh, MD, FACG⁴. P0113 - Atypical, Relapsing Type 1 Autoimmune Pancreatitis in a Patient with Breast Cancer and Rheumatoid Arthritis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.