Malignant Ossifying Fibromyxoid Tumor of the Chest Wall Metastasized to the Lung Even After Complete Resectioning of the Primary Tumor - A Case Report and a Comprehensive Review

An ossifying fibromyxoid tumor is a soft tissue neoplasm with ambiguous differentiation and low metastatic potential. Most cases involve the lower extremities, followed by the trunk, the upper extremities, and the head and neck region. It mainly arises in 40-70 years of age, and men dominate the disease's gender distribution. In the described types of ossifying fibromyxoid tumors, there are three variants: one is benign (typical), the second is malignant, which carries the risk of disease recurrence or metastases, and the third is atypical, which does not meet the criteria of either typical or malignant. Here, we present an interesting case of a malignant ossifying fibromyxoid tumor of the chest wall that metastasized to the lungs even after complete resection of the primary tumor. A 64-year-old man had a 4.0 cm malignant ossifying fibromyxoid tumor in his chest wall two years ago, and at that time, the tumor was removed entirely. On pathology review, it was noted to have 20 mitotic figures per 50 high-power fields, but no actual grade was given. He was given postoperative radiation. His recent computed tomography (CT) chest with contrast showed a new right upper lung lobe nodule measuring 0.78 cm compared to the previous contrast-enhanced CT chest six months ago. It was worrisome for metastasis. F-18 FDG positron emission tomography scan revealed sub-centimetric pulmonary nodules in the right upper lobe. Right upper lobe lung biopsy showed spindle cell neoplasm morphologically consistent with the patient's known history of malignant ossifying fibromyxoid tumor. Biopsy demonstrated fragments of the bronchial wall and alveolated lung parenchyma with a focal spindle cell proliferation demonstrating a fibromyxoid matrix. The patient was referred to the oncologist for further management. In conclusion, aggressive malignant ossifying fibromyxoid tumors can be found in atypical locations, e.g., the chest wall. Therefore, early diagnosis is crucial because of the high chances of metastasis to distant organs (including the lung) even after complete resection of the primary tumor. Even in asymptomatic patients, it is necessary to complete long-term follow-up for recurrence and metastasis surveillance of ossifying fibromyxoid tumors. Early recognition of recurrence or metastasis can decrease morbidity and mortality and improve overall organ function and patient survival.