P1566 - An Unusual Cause of Hematemesis Heralding as a Case of Polyarteritis Nodosa (PAN)

Minh Thu T. Nguyen, MD¹, Ari Young, MD¹, Edwin Lee, MD², Brandon Sprung, MD^2
1University of Rochester Medical Center, Rochester, NY; ²University of Rochester Medical Center, Strong Memorial Hospital, Rochester, NY

Introduction: Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis predominantly affecting medium-sized arteries, with incidence ranging from 2-9 cases per million individuals and peak prevalence in the 6th decade of life. While most cases of PAN are idiopathic in origin, about 7% of cases have been linked to hepatitis B infection. This disease tends to manifest with systemic symptoms and multi-organ involvement and can have gastrointestinal involvement in up to 65% of patients, including abdominal pain from mesenteric arteritis, vasculitis-induced ischemia, and gastrointestinal bleeding. We describe a rare case of PAN in a young male presenting with non-specific symptoms of subacute abdominal pain and gastrointestinal bleeding.

Case Description/Methods: A 20-year-old man presented with a 3 week history of intermittent epigastric pain unrelated to meals, nearly daily episodes of hematemesis, as well as hematochezia, anorexia, weakness, and fatigue. Initial evaluation revealed a normocytic anemia with hemoglobin of 8.8 g/dL and hematocrit of 28%. Computed tomography (CT) angiography revealed greater than 20 aneurysms arising from the medium-sized and small branches of the splanchnic abdominal arterial vasculature, with the largest aneurysm being 1.8 x 1.7 cm (Figure 1).

Given concern for underlying vasculitis, the patient completed an extensive workup (Table 1). He received a diagnosis of PAN and was started on a high dose prednisone course. Post hospital discharge he was found to have interval growth of underlying abdominal aneurysms after a month and thus was started on cyclophosphamide therapy. He eventually underwent prophylactic coil embolization of the left hepatic and gastric artery aneurysms with interventional radiology to prevent future rupture.

Discussion: Our case demonstrates a rare presentation of gastrointestinal bleeding and subacute symptoms heralding a diagnosis of PAN in a young male. While these nonspecific complaints carry a very broad differential diagnosis, this case highlights the need to consider vasculitis in the right clinical context. PAN is diagnostically challenging due to its diverse presentation and lack of specific markers for diagnosis. Prompt identification is critical given PAN has an untreated 5-year mortality rate of 13% which improves to 80% with treatment. Underlying mesenteric arteritis can lead to serious complications, such as refractory ulcers, intestinal ischemia, and bowel perforation.


Figure: Figure 1. A) CT abdomen and pelvis with IV contrast showing a large left hepatic artery aneurysm (measured up to 16.5 x 15.9 mm). B) Abdominal arteriogram depicting numerous aneurysms of mid-sized and small branches in the splanchnic abdominal arterial vasculature.

Inpatient vasculitis workup
Lab	Value	Reference range
Sedimentation rate (ESR)	88 mm/hr	0 - 15 mm/hr
C reactive protein (CRP)	25 mg/L	0 - 10 mg/L
C3 complement	208 mg/dL	90 - 180 mg/dL
C4 complement	24 mg/dL	10 - 40 mg/dL
Antineutrophil cytoplasmic antibody (ANCA)	Negative	Negative
Myeloperoxidase (MPO) antibody	0	0 - 20 U
Proteinase-3 (PR3) antibody	1	0 - 20 U
Creatine kinase (CK)	68	39 - 308 U/L
Treponema pallidum antibody	Negative	Negative
Hepatitis A IgG	Positive	Negative
Hepatitis B surface antigen	Negative	Negative
Hepatitis B surface antibody	Negative	Negative
Hepatitis B core antibody	Negative	Negative
Hepatitis C antibody	Negative	Negative
Cryoglobulin	Negative	Negative
HIV 1&2 antigen/antibody	Nonreactive	Nonreactive
Antinuclear antibody (ANA)	Negative	Negative
Rheumatoid factor (RF)	Negative	Negative
Anti-double stranded DNA (Anti-dsDNA)	Negative	Negative

Table: Table 1. Inpatient labwork obtained for workup of vasculitis.


Disclosures:
Minh Thu Nguyen indicated no relevant financial relationships.
Ari Young indicated no relevant financial relationships.
Edwin Lee indicated no relevant financial relationships.
Brandon Sprung indicated no relevant financial relationships.


Minh Thu T. Nguyen, MD¹, Ari Young, MD¹, Edwin Lee, MD², Brandon Sprung, MD². P1566 - An Unusual Cause of Hematemesis Heralding as a Case of Polyarteritis Nodosa (PAN), ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.