Case report
Multiple Myeloma Presenting as Digital Ischaemia Mimicking Rheumatoid Vasculitis: A Diagnostic Challenge
OD04-OD06
Correspondence
Dr. Suryanarayana Reddy Kovvuri,
Postgraduate Student, Department of General Medicine, Saveetha Medical College
and Hospital, Saveetha Nagar, Thandalam, Chennai-602105, Tamil Nadu, India.
E-mail: drsurya9999@gmail.com
Multiple myeloma commonly presents with anaemia, bone pain, renal dysfunction, hypercalcaemia, and lytic bone lesions. However, digital ischaemia and gangrenous ulceration as an initial manifestation are exceedingly rare and may mimic rheumatologic or vasculitic disorders, leading to diagnostic delay. A 45-year-old female with a history of type 2 diabetes mellitus and previously treated as seronegative rheumatoid arthritis presented with progressive blackish discolouration and ulceration of the right ring finger associated with whitish discharge for one month. She also complained of bilateral pedal oedema, difficulty in walking, low-grade fever, and melaena. Initial evaluation raised suspicion for rheumatoid vasculitis, Raynaud phenomenon, or peripheral vascular disease. Rheumatologic workup including rheumatoid factor, anti-Cyclic Citrullinated Peptide (anti-CCP) antibodies, Antinuclear Antibody (ANA) immunoblot, Antineutrophil Cytoplasmic Antibody (ANCA) profile, and nail fold capillaroscopy was negative. Arterial Doppler of the right upper limb demonstrated normal triphasic flow. Laboratory investigations revealed severe anaemia (haemoglobin 4.3 g/dL), thrombocytopenia, leucocytosis, markedly elevated inflammatory markers, and poorly controlled diabetes mellitus. Computed tomography of the thorax and abdomen demonstrated multiple extensive lytic lesions involving the axial and appendicular skeleton with associated soft tissue components, pathological destruction involving the humeral head, diffuse osteopenia, and hepatosplenomegaly. Bone marrow biopsy revealed hypercellular marrow largely replaced by sheets of plasmacytoid cells with suppression of normal haematopoietic elements. Immunohistochemistry showed diffuse CD138 positivity, confirming plasma cell neoplasm favouring multiple myeloma. The patient was initiated on bortezomib, lenalidomide, and dexamethasone-based chemotherapy. This case highlights an unusual presentation of multiple myeloma presenting as digital ischaemic ulceration mimicking rheumatologic vasculitis. In patients with atypical digital ischaemia associated with cytopenias, elevated inflammatory markers, and systemic manifestations, haematological malignancies including multiple myeloma should be considered in the differential diagnosis to avoid delay in diagnosis and management.