2020 Volume 36 Issue 1 Pages 169-177
Smooth muscle tumors of uncertain malignant potential (STUMP) are rare; however, reports in the available literature describe recurrence and metastasis associated with these neoplasms. We report a case of STUMP that occurred after laparoscopic myomectomy in a patient diagnosed with a leiomyoma preoperatively.
A 44-year-old woman developed menorrhagia at 35 years of age and underwent magnetic resonance imaging (MRI), which revealed a tumor (55 mm in size) at the bottom of the uterus, and we suspected cellular myoma. MRI revealed enlargement of the lesion when she was 38 years old; therefore, we performed laparoscopic myomectomy. The tumor showed degeneration and was carefully removed after morcellation. The patient was diagnosed with benign leiomyoma based on histopathological findings; therefore, outpatient management was discontinued 3 months postoperatively. An enlarging tumor was detected under the wound when the patient was 40 years old, for which she underwent thorough evaluation. Computed tomography revealed masses in the subcutaneous tissue and on the liver surface, and positron emission tomography revealed tracer uptake in these masses and in a part of the uterus. We diagnosed the patient with a benign leiomyoma and performed simple hysterectomy, bilateral adnexal surgery, and subcutaneous and intraperitoneal tumor extirpation for diagnostic purposes because malignancy could not be excluded. We diagnosed STUMP based on histopathological findings of nuclear atypia and nuclear fission. The tumor was considered to have originated from the residual uterus and intraperitoneal dissemination. The residual masses disappeared postoperatively and did not recur.
Careful preoperative evaluation, meticulous histopathological examination of the excised specimens, and postoperative follow-up are warranted in women with atypical leiomyomas that show low malignant potential preoperatively.
