Extremely rare synchronous primary neoplasms in testicular cancer patients.

Objectives: This study analyzes the incidence of multiple primary malignant neoplasms (MPN) in patients with testicular cancer (TC), the results are compared with literature findings and assess the rarest subgroup of patients with MPN.
Patients and Methods: Clinical data of 1870 patients with TC treated or followed up in a single center in the period of 5/1970-12/2018 were collected and analyzed retrospectively in focus of the occurrence of MPN.
Results: The overall incidence of MPN was 150 (8.02 %). There were 89 cases of bilateral TC (59.3 %), of these 8 cases were synchronous (diagnosed within three months period from the primary diagnosis) and 81 metachronous (9 % and 91 % respectively). Non-testicular other primary malignancies (OPM) occurred in 61 cases (40.7 %), of which 59 cases were metachronous (96.7 %) and two cases were synchronous (3.3 %). Metachronous malignancies included mainly prostate cancer (n = 17 patients), kidney cancer (n = 13 patients) and colorectal cancer (n = 12 patients). Synchronous OPM was found in two patients.
Conclusion: In our study we registered two cases of synchronous OPM, both histologically clear cell renal cancer. We have analyzed clinical characteristics, diagnosis and treatment strategies of synchronous OPM, in order to improve its diagnosis and therapy (Fig. 3, Ref. 22).