The Diagnostic Dilemma in IgG4-related disease (IgG4-RD)
Why Does IgG4-RD Take So Long to Diagnose?
An IgG4ward! CanJAM presentation by Dr. Mollie Carruthers
Watch the full presentation here:
Speaker: Dr. Mollie Carruthers, MD – Canadian leader and global expert in IgG4-RD
Event: IgG4ward! CanJAM (Canadian Virtual Patient Jamboree)
Original Air Date: October 17, 2025
Traditional Chinese translation available: Dr. Carruthers’ presentation slides were translated into Traditional Chinese by her patient, Danni Luo, to help make this rare disease education accessible to more patients and caregivers worldwide. View the Traditional Chinese Translation Here
The sections below summarize key diagnostic challenges discussed in the presentation, with more detail available in the full video above.
Why Diagnosis is Often Delayed
IgG4-related disease is a rare, complex condition that can affect nearly any organ system. Because symptoms vary widely and often resemble more common diseases, many patients see multiple specialists before IgG4-RD is recognized.
In this presentation, Dr. Mollie Carruthers explains the most common diagnostic challenges and why delays are a shared reality in rare disease care — not the fault of any one provider.
The IgG4-RD Diagnostic Journey
Dr. Carruthers compares the diagnostic process to a river system. While some diseases flow quickly to a diagnosis, IgG4-RD often winds through many tributaries before reaching its destination.
One major reason is the disease’s wide range of presentations. IgG4-RD may involve the pancreas or liver, the eyes or salivary glands, blood vessels, kidneys, or multiple organs at once. Because these symptoms often resemble more common conditions, IgG4-RD is frequently not recognized early.
Key Diagnostic Challenges in IgG4-RD
Dr. Carruthers highlights several factors that contribute to delayed diagnosis, including:
The rarity and complexity of IgG4-RD
Wide variation in symptoms and organ involvement
Limited familiarity with the disease across specialties
The need for specialized testing and biopsy
The Importance of Biopsy
A central message of this talk is that tissue biopsy is often essential. IgG4-RD frequently causes mass-like lesions that raise concerns for cancer, and biopsy helps distinguish IgG4-RD from other serious conditions.
Understanding the role of biopsy can help patients advocate for timely diagnosis and appropriate care.
The Role of Patients & Advocacy
Dr. Carruthers emphasizes that patients and caregivers can play an important role by asking informed questions, sharing their stories with clinicians, and connecting with trusted organizations like IgG4ward!
The patient-translated Chinese slides included with this presentation are one example of how patients can expand access to rare disease education globally.
Watch the full presentation
This written overview highlights key themes, but the full video includes visual explanations and a live Q&A covering imaging, lab testing, and coordinated care.
