Objectives This paper reports on the two cases of PHO that transformed into SHO under the influence of bronchogenic carcinoma.

Results The patients had not have any sign of PHO activity until the last 3 and 4 months, when a malignant process of the lungs developed and reactivated all symptoms of the disease (joint swelling, moist palms and soles, unpleasant odour of perspiration, deeper folds on the forehead and deeper nasolabial furrow, enlarged fingers, erythema around the nails). Scintigraphy showed increased radioisotopes accumulation in particular regions of the skeleton.

Conclusion To our knowledge, similar cases have not been described in literature.