Introduction/Background*Perivascular epitheliod cell tumors (PEComas) are rare mesenchymal neoplasms. Uterine PEComa is extremely rare and only limited evidence is still available.

Methodology This is a single-center retrospective study. Charts of consecutive patients who had treatment (from 01/01/2010 to 12/31/2020) for newly diagnosed uterine PEComas were retrieved. Five-year survival outcomes were assessed using Kaplan-Meier and Cox proportional hazard models.

Result(s)*Data of 23 patients with newly diagnosed PEComas were analyzed. Mean (SD) patients‘ age was 52 (14) years. Twenty-two patients had a surgical cytoreductive attempt. In one case surgery was not performed due to the presence of an extra-abdominal spread. Overall, seven (30%) patients had disease outside the uterus at the time of surgery. Complete cytoreduction (no macroscopic residual tumor) was achieved in 19 patients. Complete cytoreduction was not completed in three patients who gross extrauterine disease and in the aforementioned patient who had not surgery. Eleven (48%) patients had adjuvant treatments, consisting in anthracycline-based chemotherapy (n=4),gemcitabine-based chemotherapy (n=2), mTOR inhibitors (n=4) and hormonal treatment (n=1). Median (range) follow-up as 23 (2, 99) months. Eleven (48%) recurrences occurred with a mean (SD) progression free-survival of 14 (11) months. After a median (range) follow-up of 23 (2, 99) months, nine (39%) patients died of disease. Residual tumor at surgery was the only factor correlating with the risk of developing recurrent disease (p=0.023) and worse overall survival (p=0.014). In our small series, stage of disease and adjuvant therapy administration had no impact on survival outcomes.

Conclusion*Uterine PEComa represents a rare and aggressive entity. Molecular/genomic profiling of the disease is necessary to predict response to treatment. Further collaborative investigations are warranted to assess the role of various prognostic factors and evaluate the most effective surgical and medical treatment modalities.