Diagnostic Dilemma of Paraneoplastic Rheumatic Disorders: Case Series and Narrative Review

Area of Science:

• Rheumatology
• Oncology
• Internal Medicine

Background:

• Paraneoplastic rheumatic disorders (RDs) manifest as rheumatic symptoms preceding, concurrent with, or following malignancy diagnosis.
• These disorders are clinical expressions of occult cancer, distinct from direct tumor effects or metastasis.
• Diagnosis is challenging due to symptom overlap with common rheumatic diseases, complicating treatment decisions.

Observation:

• Presents four diagnostic dilemma cases of RD: leukocytoclastic vasculitis/C3 glomerulopathy, scleroderma, Raynaud's syndrome/lupus-like syndrome, and inflammatory myositis.
• Highlights minimal or no responsiveness of paraneoplastic RDs to standard rheumatic treatments.
• Reviews literature on paraneoplastic rheumatoid arthritis and rheumatic presentations associated with immune checkpoint inhibitors (ICIs).

Findings:

• Paraneoplastic RDs present atypically, requiring careful consideration beyond common rheumatic disease diagnoses.
• Standard rheumatic treatments are often ineffective for paraneoplastic RDs, underscoring the need for underlying cancer identification.
• Interdisciplinary collaboration is essential for accurate diagnosis and management.

Implications:

• Clinicians must be aware of atypical paraneoplastic RD presentations to avoid diagnostic delays.
• Prompt identification and treatment of the underlying malignancy are paramount for managing these disorders.
• Emphasizes the necessity of collaborative care between rheumatologists, oncologists, and primary care practitioners for optimal patient outcomes.