Hematologic malignancies masquerading as rheumatologic diseases: A case series and review.

Background: Hematologic malignancies can mimic rheumatologic diseases, presenting a significant diagnostic challenge due to overlapping clinical features. This study highlights 5 cases of hematologic malignancies presenting as rheumatologic disorders and discusses the diagnostic complexities involved.

Methods: The patients, aged 64 to 78, presented with diverse rheumatologic symptoms including polyarthritis, vasculitis, Raynaud phenomenon, and systemic symptoms such as weight loss, fatigue, and night sweats. Initial workups suggested rheumatologic diagnoses, leading to delays in recognizing the underlying malignancies. Methods: The diagnostic journey involved extensive laboratory testing, imaging, and, in all cases, bone marrow biopsies, which ultimately revealed hematologic malignancies: angioimmunoblastic T-cell lymphoma (AITL), extranodal marginal zone lymphoma, myelodysplastic syndrome (MDS), and multiple myeloma. Misleading initial findings, such as autoimmune serologies and transient responses to immunosuppressive therapy, complicated the diagnostic process. Methods: Ultimately, the patients included in this case series benefited from hematological malignancy-specific therapies. Delayed diagnosis impacted the treatment course and outcomes.

Results: Outcomes varied: 2 patients achieved symptom control with targeted therapy, while others experienced complications such as infections or disease progression, ultimately leading to mortality in some cases. Patient frustrations underscored the psychologic toll of diagnostic delays.

Conclusions: Hematologic malignancies can present as atypical or refractory rheumatologic diseases, emphasizing the need for vigilance in patients with unusual clinical courses. Early consideration of malignancy in differential diagnoses, especially with atypical serologic or histopathologic findings, is critical to improving outcomes.