[Cancer recurrence or sarcoidosis: the essential contribution of pathology]

The development of pulmonary nodules or lymph nodes in the course of a malignancy, in particular breast cancer, can sometimes correspond to the onset of sarcoidosis. Osteolytic lesions can simultaneously occur which further strengthens the impression of a metastatic disease. No particular test, biological markers or imaging technique, has a satisfactory discriminating power and a biopsy is needed to establish the correct diagnosis and decide on the adequate treatment. The concomitance of sarcoidosis and cancer raises the possibility of a granolumatous disease.