Metachronous malignant tumors in ipsilateral salivary glands

Salivary gland tumors usually appear in solitary mass in single salivary gland. The coexistence of tumors with different histological types occurring within a unilateral parotid gland is an extremely rare event. We experienced a case which two different types of malignant tumors developed at different time points in same gland; metachronous tumors. The second tumor was excised widely and reconstruction was performed by free tissue transfer. Sensory and motor nerve to the left cheek appeared to be intact, and circulation was adequate. This rare case was presented in this article.

Cáncer sincrónico y metacrónico detectado con PET/CT en población oncológica / Multiple primary malignant neoplasms detected by PET/CT in cancer patients

Background Imaging with F18-fluorodeoxyglucose PET/CT is used to determine sites of abnormal glucose metabolism and can be used to characterize and localize many types of tumors. Aim To assess the prevalence of multiple primary malignant neoplasms (MPMN) detected by PET/CT in cancer patients. Material and Methods F18-fluorodeoxyglucose PET/CT scans performed to 800 patients with a newly diagnosed cancer or with already treated tumors were retrospectively reviewed. In patients whose examination described incidental findings not related to the primary tumor, a research was done about further laboratory, imaging or pathological studies. Results In 188 PET/CT scans (23%) an incidental finding was found. Of these, 66 (35%) were considered as MPMN, 12 as atypical metastases of a known primary tumor, 14 as false positive images (inflammatory or physiologic uptake) and 29 as benign or low grade tumors. In 67 cases (36% of all incidental tumors), the finding was not confirmed. Seven percent of patients with a newly diagnosed tumor had a synchronic MPMN detected by PET/CT. Nine percent of patients with treated tumors developed a metachronous MPMN during their follow up. The most common incidental tumors were thyroid cancer in 15 cases, kidney cancer in 13, lung cancer in 10, colorectal carcinoma in 9, breast cancer in 6, prostate cancer in 4, non-Hodgkin lymphoma in 3 and pancreatic cancer in 2. Conclusions A MPMN is detected by PET/CT in a significant number of cancer patients.