I believe this patient has an autoimmune disorder manifested by muscle weakness due to myositis, pancytopenia due to bone marrow necrosis and autoimmunity, leg edema due to inflammation-related capillary leak and myositis, and probable intestinal dysmotility.
Note that I make this diagnosis despite the normal serologic tests over the years. Oftentimes, diagnoses of autoimmune disorders are made on clinical grounds. Laboratory tests are often confirmatory but are not mandated to be abnormal in the face of a strong clinical presentation and an extensive work-up that has ruled out malignancy and infection.
Infection and malignancy seem quite unlikely here.
Muscle: CK elevated at 800, aldolase elevated at 28. Right quadriceps ultrasound showed diffuse edema, consistent with inflammation. Needle muscle biopsy: myositis
Autoimmune serologies continue to be negative.
Hydrogen breath test abnormal. This finding is consistent with bacterial overgrowth, likely related to autoimmune disorder-related bowel dysmotility.
Medscape Rheumatology © 2011
Cite this: Stephen Paget. Swelling, Pain, and Pancytopenia: An Elusive Diagnosis - Medscape - Apr 04, 2011.