Carcinoma of unknown primary radiologically presenting as myeloma

An elderly male patient presented with complains of bone pain lower backache and on initial investigation was found to be mildly anaemic raised erythrocyte sedimentation rate, C reactive protein, mild hypercalcemia serum creatinine levels. On imaging studies multiple bony lytic lesions were seen predominantly in axial skeleton. A provisional diagnosis myeloma made he further investigated for M proteins marrow abnormalities. Serum Urine examination negative paraproteins but showed clusters atypical epithelial cells pointing towards metastatic carcinoma, primary site/origin which remain unknown despite using immunohistochemical markers along PET (Positron Emission Tomography) scan favoring a Carcinoma Unknown Primary (CUP). This report suggest that must considered as differential skeletal equivocal findings hypercalcemia, abnormal renal function, anaemia avoid the diagnostic pitfall labeling these patients Multiple Myeloma.