Vertebral bone metastasis of small cell carcinoma of lung in a diabetic patient, initially diagnosed as pyogenic vertebral osteomyelitis.

A 40-year-old man with a 3-year history of uncontrolled NIDDM, 2-pack/month cigarette smoking habit and alcohol abuse, was admitted to our university hospital. He presented with severe back pain, persistent cough and fever. A left lung infiltrate was noted on chest X-ray film. Staphylococcus aureus was isolated from arterial blood. Thoracic bone destruction with pleural mass lesion confirmed by computed tomography (CT) and magnetic resonance image (MRI). These findings mislead our diagnosis to pyogenic osteomyelitis associated with NIDDM. An absence of marked clinical and roentgenological improvement after antibiotic therapy and strict glycemic control with insulin was noted. This suggested to us the need for needle biopsy of the osteolytic and mass lesions confirmed by imaging techniques. This resulted in making the diagnosis of metastasis of small cell carcinoma from the left lung. The correlation between NIDDM and pulmonary small cell carcinoma possibly induced by genetic abnormality remains to be resolved. By making the most of imaging techniques and needle biopsy, the possibility of pulmonary small cell carcinoma complicating NIDDM can be appropriately evaluated.