Low-grade fibromyxoid sarcoma presenting clinically as a primary ovarian neoplasm: a case report

Low-grade fibromyxoid sarcoma is an uncommon, deceptively bland mesenchymal neoplasm that typically occurs in the deep soft tissues of the proximal extremities of young to middle-aged patients. Intra-abdominal low-grade fibromyxoid sarcomas are distinctly rare. We describe the first reported example of this sarcoma involving the ovary. The 42-year-old patient presented with progressing abdominal pain and urinary frequency. Computed tomographic imaging of the abdomen and pelvis showed a 14-cm left-sided pelvic mass. The patient underwent surgical resection and, intraoperatively, a left ovarian mass was identified that extended to both the left hypogastric artery and the left ureter. The resected specimen consisted of a 17-cm tan, fleshy mass containing grossly recognizable nodules of gelatinous, myxoid tissue and a small rim of normal ovary. Microscopic examination of the neoplasm revealed a cytologically bland spindle cell proliferation set in a collagenized stroma that abruptly transitioned to nodules of a myxoid stroma with a well-formed capillary vasculature, features characteristic of low-grade fibromyxoid sarcoma. On the basis of the diagnosis, the patient was clinically staged as a retroperitoneal sarcoma with secondary ovarian involvement. The patient has stable residual disease 11 months postoperatively. This case adds to the literature of intra-abdominal low-grade fibromyxoid sarcoma and expands the list of malignant mesenchymal neoplasms that may involve the ovary.