Sarcoidosis is a benign systemic disease characterized by the formation of granulomas in almost all organs. A frequent combination of sarcoidosis and various neoplastic diseases has been noted. Differential diagnosis of sarcoidosis and malignancy is extremely difficult. Currently, there are no diagnostic methods, other than histological examination, to distinguish sarcoidosis from a tumor process. Biopsy with histological examination is the reliable method. In the considered clinical case, a combination of sarcoidosis and metastatic sigmoid colon cancer is presented. PET-CT revealed the same hypermetabolic activity in the cervical, supraclavicular, intrathoracic lymph nodes and metastases in the tissues of the anterior abdominal that did not allow differential diagnosis of sarcoidosis and metastatic process. Sarcoidosis was proven only by histological examination of the removed cervical lymph node; a number of radiological signs suggested sarcoidosis of the intrathoracic lymph nodes, but their histological examination was not performed. The presented case is intended to alert oncologists regarding sarcoidosis, which often accompanies a disseminated tumor process.

Keywords: histological picture of sarcoidosis, diagnosis of sarcoidosis, sigmoid colon cancer, metastases, sarcoidosis