[Subcutaneous nodules with malignant presentation, but caused by infection]

Three patients, a woman aged 32, a boy aged 6.5 and a man aged 56 years, presented with a subcutaneous mass suggesting a malignancy: respectively a rubbery swelling, painful to the touch below the left scapula, a partly massive, partly soft swelling on the inside of the left upper leg, and a non-fluctuating mass near the right eighth rib, parasternally. Additional diagnostic investigation revealed an infectious cause: respectively Mycobacterium tuberculosis, Bartonella henselae and Salmonella typhi. Antimicrobial therapy was successful. Subcutaneous masses suspected of being a benign or malignant tumour are sometimes caused by an infection. The differential diagnosis is extensive. Sometimes the travel anamnesis yields helpful information. It is concluded that besides histopathological examination, microbiological investigation can play a major role in the evaluation of subcutaneous masses.