Ossifying fibromyxoid tumor (OFMT) of the soft parts is a mesenchymal neoplasm of uncertain lineage. Fibromyxoid matrix and peripheral metaplastic bone are common histological features of this type of tumor. In the present study, a case of OFMT in a 33‑year‑old female was reported. The patient was referred to the First Affiliated Hospital of China Medical University (Shenyan, China) in January 2018. The patient had developed a mass in the left upper arm 6 months prior to presentation, which was slowly enlarging. The tumor was 1.5 cm in diameter, with hard texture. Histologically, the tumor showed a clear boundary with no invasion into the adjacent tissue. The majority of tumor cells were round and medium‑sized, with abundant pale cytoplasm, without obvious atypia and densely arranged in sheets. The tumor tissue was characterized by cartilage‑like morphology and fibromyxoid and hyalinization matrix. Mitotic index was <1/10 high‑power fields. Additionally, tumor cells were positive for S‑100 and vimentin expression, but negative for smooth muscle actin, CD34, cytokeratin, desmin, human melanoma black 45 and melanoma A. Ki67 index was ~1%. The patient underwent surgery and the tumor was totally removed. No recurrence was observed at the final 6‑year follow‑up. Based on the aforementioned findings, the patient was diagnosed as typical OFMT. Slow growth and clear boundaries often suggest an indolent nature to this type of tumor. However, close follow‑up should be performed due to its malignant potential. 

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