Carcinoma of Unknown Primary Mimicking Multiple Myeloma

Pathological fractures due to secondaries in the bone are common with carcinoma of lung, breast, prostate, and in multiple myeloma. Multiple pathological fractures after a trivial fall, indicating metastases warrants detailed investigations for the search of primary. Skeletal secondaries should be strongly suspected in addition to obvious diagnosis of multiple myeloma in such cases.

We report a case of pathological fractures at multiple sites: The vertebral column, proximal shaft of femur, and contralateral fracture neck of femur. This patient presented with typical features of multiple myeloma, but on complete evaluation was found to be due to extensive metastases in the bones secondary to adenocarcinoma, the primary site of which remained unknown, despite extensive search and evaluation, making it a case of carcinoma of unknown primary.

While dealing with patients with extensive skeletal lesions and pathological fractures, secondaries due to adenocarcinoma elsewhere should be kept in mind along with other probabilities such as multiple myeloma.