Multiple myeloma or metastatic carcinoma breast: diagnostic dilemma in a case presenting with lytic bony lesion

Carcinoma breast is common tumor which tends to metastasize to different organs but diagnostic difficulty may arise if known case of carcinoma eventually presents with another secondary malignancy with clinical features which closely mimics with metastatic carcinoma. This overlapping of symptoms may lead to delayed diagnosis of secondary malignancy with worsening of the condition of patient due to lack of specific treatment.The present case is being reported where a known case of primary breast carcinoma presented with scapular erosions suggesting metastasis. However, despite treatment her worsening condition necessitated further work up revealing multiple myeloma. The case signifies the pitfall due to overlapping of symptoms and draws attention to the fact that every known case of primary carcinoma suggestive of metastasis should also be investigated in light of another secondary malignancy. Early diagnosis of secondary malignancy followed by specific treatment would be helpful in improved prognosis of the patient.