Primary Gastrointestinal Stromal Tumor Mimicking as Gynecologic Mass: Characteristics, Management, and Prognosis.

Background: Primary gastrointestinal stromal tumor (GIST)-mimicking gynecologic masses are easily misdiagnosed. This study aimed to investigate the clinicopathological features, management, and prognosis of primary GIST mimicking as gynecologic mass.

Methods: Clinicopathological and survival data of GIST mimicking as gynecologic mass admitted to our center from January 2005 to December 2017 were retrospectively analyzed.

Results: Thirty-eight patients were included. The most common primary tumor site was the jejunoileum (n = 33, 86.9%), and 33 patients (86.9%) were classified as high recurrence risk. The short-term outcomes of operative incision length (P = 0.004), time to gas passage (P = 0.002), and hospital stay (P = 0.012) with laparoscopy-assisted resection were significantly shorter than those with open resection, showing no significant differences of long-term outcomes. With a median follow-up of 56 mo for 31 patients (81.6%), 18 (58.1%) received adjuvant therapy with imatinib. The 5-year disease-free survival and disease-specific survival of pelvic high-risk GIST was 37.0% and 48.3%, respectively; both were significantly lower than those of the other female high-risk group (both P < 0.05).

Conclusions: GIST mimicking as gynecologic mass is not uncommon, most originate from the jejunoileum and have a high risk of recurrence. Laparoscopy-assisted resection may be preferable for more favorable short-term outcomes. Compared with the other female high-risk GIST, pelvic high-risk GIST has a significantly worse prognosis; a longer duration of adjuvant therapy with imatinib than recommended may be beneficial.