Primary renal myxofibrosarcoma in a woman: A case report and literaturereview

Abstract

A 45-year-old previously healthy woman presented to our hospital with a right abdominal mass. Abdominal computed tomography (CT), magnetic resonance imaging, and bone scanning revealed a 15 cm×10 cm×14 cm, well-delineated, retroperitoneal tumor originating from the right kidney. No metastases detected. The patient underwent successful extirpation of the renal tumor. The tumor showed 50% necrosis without perirenal fat infiltration, and it was diagnosed as a high-grade (grade 3) myxofibrosarcoma without nodal positivity, according to the French Federation of Cancer Centers Sarcoma (FNCLCC) grading system. Tumor immunohistochemical staining revealed positive staining for CD34, Ki67, smooth muscle actin (SMA), and cluster of differentiation 68 (CD68), and negative staining for S100 protein, desmin, mast/stem cell growth factor receptor (c-kit), and melanoma marker antibody (HMB45). Three months post-surgery, follow-up CT revealed no new abdominal metastasis, and the patient is currently receiving routine follow-up without any additional systemic therapy. Myxofibrosarcoma of the kidney is an uncommon soft tissue tumor, and radical surgery is the treatment of choice. Long-term follow-up is recommended because of the tumor's aggressive invasiveness and potential for distant metastasis.

Renal myxoma – a case report of a rare kidney tumor, its differential diagnosis and literature review

“…Renal origin of myxofibrosarcoma is uncommon and seen in less than 3% of all primary renal neoplasms. 8 RMS often contains hypocellular and hypercellular areas with variable degrees of rhabdomyoblastic differentiation. It is usually positive for desmin, myogenin, and MyoD1.…”

“…Low‐Grade Myxofibrosarcoma has curvilinear vessels with marked pleomorphic scattered cells in between. Renal origin of myxofibrosarcoma is uncommon and seen in less than 3% of all primary renal neoplasms 8 …”