Heart tumor disguised as vasculitis

The Great Imposter: When a Heart Tumor Mimics a Serious Artery Disease

Lena Kashyap in Health & Wellness August 2025 • 4 min read.

"Unraveling the Mystery of Left Atrial Myxoma and Polyarteritis Nodosa"

Vasculitis, a condition that impairs the function of tissues and organs due to inflammation of blood vessels, can be tricky to diagnose. While the Chapel Hill consensus provides criteria for classifying vasculitis, several other conditions can mimic its symptoms. These imposters include infections, cholesterol embolisms, fibromuscular dysplasia, and, surprisingly, a heart tumor known as atrial myxoma.

Atrial myxomas are non-cancerous tumors that typically grow in the left atrium of the heart. While benign, these tumors can cause a range of symptoms that overlap with those of vasculitis, leading to potential misdiagnosis. A recent case highlights this diagnostic challenge, involving a 32-year-old woman initially diagnosed with polyarteritis nodosa, who was later found to have a left atrial myxoma.

This article delves into the intriguing case of a heart tumor masquerading as a systemic vascular disease, shedding light on the importance of considering alternative diagnoses and employing comprehensive diagnostic approaches. We'll explore the symptoms, diagnostic process, and treatment strategies for both conditions, emphasizing the need for vigilance in differentiating between vasculitis and its mimics.

The Case of the Mimicking Myxoma: A Diagnostic Puzzle

A 32-year-old woman sought medical attention, reporting fatigue, weakness, joint pain (arthralgia), muscle pain (myalgia), and a weight loss of 5 kg over six months. She was already taking metoprolol for hypertension. Her physical examination revealed a slightly elevated temperature (37.5°C), high blood pressure (160/100 mm Hg), and a pulse rate of 85 beats per minute. Doctors noted no neurological or cardiopulmonary abnormalities. However, she exhibited ischemia (reduced blood flow) in the second, third, and fourth digits of her right lower extremity.

Initial laboratory tests revealed several abnormalities:

White blood cell count: 8600/mm³ (74% neutrophils)
Hemoglobin: 10.7 g/dL
Mean corpuscular volume: 81.9 fL
Platelet count: 370000/mm³
Erythrocyte sedimentation rate: 92 mm/hour
C-reactive protein: 8.4 mg/dL
Elevated liver enzymes: ALT (162 U/L), AST (53 U/L), alkaline phosphatase (94 U/L), GGT (63 U/L)
Normal total bilirubin (0.2 mg/dL), total protein (7.7 g/dL), albumin (4 g/dL), and urea (58 mg/dL)

Coagulation tests were normal, and urine analysis was negative for proteinuria and hematuria. Serum electrophoresis showed polyclonal gammopathy. Further testing ruled out rheumatoid factor, anti-nuclear antibody, anti-neutrophil cytoplasmic antibody, cryoglobulin, antiphospholipid antibodies, and various viral infections. Notably, the patient tested positive for hepatitis B virus (HBV) surface antigen, with specific HBV-DNA titres. Based on these initial findings, the patient was diagnosed with polyarteritis nodosa and started on corticosteroid treatment. Lamivudine was added due to the planned immunosuppression.

A Twist in the Tale: Unmasking the True Culprit

Despite treatment for polyarteritis nodosa, the patient continued to experience fatigue, weakness, and hypertension. These persistent symptoms prompted doctors to perform an echocardiography, which revealed a 3.2×2 cm mass in the left atrium. Further investigation and histopathological confirmation after surgical removal of the lesion led to the correct diagnosis: atrial myxoma. The steroid treatment was gradually reduced and eventually stopped. Additionally, magnetic resonance angiography ruled out vasculitis, revealing normal visceral arteries without aneurysms or occlusions.

This case underscores the importance of considering alternative diagnoses when symptoms don't align perfectly with initial assessments. While immunosuppressive agents are standard for vasculitis, atrial myxomas require surgical intervention. Clinicians must remain vigilant about vasculitis mimics to ensure accurate diagnosis and appropriate treatment.

The patient continues to be monitored, showing normal inflammatory markers and remaining symptom-free. This case serves as a reminder that even with established diagnostic criteria, medical mysteries can arise, demanding a comprehensive and nuanced approach to patient care.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.3349/ymj.2015.56.4.1165, Alternate LINK

Title: Left Atrial Myxoma Mimicking Polyarteritis Nodosa

Subject: General Medicine

Journal: Yonsei Medical Journal

Publisher: Yonsei University College of Medicine

Authors: Gokhan Sargin, Taskin Senturk

Published: 2015-01-01

Everything You Need To Know

What is a left atrial myxoma?

A left atrial myxoma is a non-cancerous tumor that commonly develops in the left atrium of the heart. Despite being benign, these tumors can lead to symptoms that are similar to those of serious conditions, such as polyarteritis nodosa. The presence of a left atrial myxoma in the heart can cause significant implications for health if left untreated. The tumor's location and potential to cause blockages or release substances can result in various symptoms, highlighting the importance of early detection and accurate diagnosis. Its presence may impede heart function or detach and travel through the bloodstream causing complications such as stroke or blockages.

What is polyarteritis nodosa?

Polyarteritis nodosa is a serious disease affecting blood vessels, leading to inflammation (vasculitis) which then can impair the function of the organs and tissues. The Chapel Hill consensus provides guidelines to help classify it, however, numerous other conditions can mimic its symptoms, leading to possible misdiagnosis. It’s important to identify it for appropriate management and treatment to prevent further damage. The consequences can be severe, including organ damage, and if left untreated, may lead to serious complications and even death.

What were the symptoms in the case described?

The main symptoms in the case were fatigue, weakness, joint pain (arthralgia), muscle pain (myalgia), and weight loss. In addition, the patient had ischemia in the right lower extremity. Initial lab tests revealed several abnormalities, including elevated white blood cell count, hemoglobin, platelet count, and erythrocyte sedimentation rate. Also, C-reactive protein and liver enzymes were elevated. Furthermore, the patient tested positive for hepatitis B virus surface antigen, with specific HBV-DNA titres. These symptoms and lab results can be seen in both a patient with polyarteritis nodosa and a patient with a left atrial myxoma, creating a challenge for accurate diagnosis.

Why is it difficult to diagnose the disease?

The diagnostic challenge arises from the overlapping symptoms of a left atrial myxoma and polyarteritis nodosa. Both conditions can cause similar symptoms such as fatigue, joint pain, and abnormalities in blood tests like elevated inflammatory markers. This similarity can lead to misdiagnosis, as seen in the case where the patient was initially diagnosed with polyarteritis nodosa. To avoid misdiagnosis, it's crucial to consider alternative diagnoses and use a variety of diagnostic approaches, including echocardiography and magnetic resonance angiography, to accurately identify the underlying cause of the symptoms. This highlights the importance of thorough investigation and careful evaluation of symptoms and test results.

What are the treatments for polyarteritis nodosa versus a left atrial myxoma?

The treatment for polyarteritis nodosa typically involves corticosteroids and immunosuppressants to reduce inflammation and prevent further damage to the blood vessels. In the case of the 32-year-old woman, she was started on corticosteroid treatment and lamivudine due to the planned immunosuppression. The treatment for a left atrial myxoma, on the other hand, is surgical removal of the tumor. In this case, after the correct diagnosis of a left atrial myxoma, the steroid treatment was gradually reduced and eventually stopped. The contrast in treatment strategies underscores the necessity of an accurate diagnosis to ensure patients receive the most appropriate and effective care.