Multiple cardiac myxofibrosarcomas with complete right pulmonary artery occlusion: a case report

Myxofibrosarcoma is one of the most common sarcomas in the extremities of elderly patients. We analysed the clinicopathologic features in a series of 75 patients. All patients were adults (range, 22-91 years; median, 66 years) with an approximately equal incidence in men and women. Thirty-five tumors arose in the lower and 25 in the upper extremities, nine on the trunk, two each in the retroperitoneum and the head and neck region, and one each in the pelvis and penis. Forty-eight cases (69.5%) were located in dermal or subcutaneous tissues. Distinctive histologic features included the following: a commonly nodular growth pattern; a myxoid matrix containing elongated, curvilinear capillaries; and fusiform, round or stellate tumor cells with indistinct cell margins, slightly eosinophilic cytoplasm, and hyperchromatic atypical nuclei. These lesions varied from a hypocellular, mainly myxoid, and purely spindle-cell appearance (low-grade neoplasms) to high-grade, pleomorphic (malignant fibrous histiocytoma-like) lesions with multinucleated giant cells, high mitotic activity, and areas of necrosis. Immunohistochemistry in 44 cases revealed only vimentin and occasional actin positivity. Ultrastructurally, tumor cells had a fibroblastic phenotype. DNA flow cytometry and proliferation analysis showed an association between aneuploidy and histologic grade. An average follow-up of 45 months (range, 5-300 months) in 60 cases has revealed local recurrence in 33 cases (54%). Thirteen patients developed metastases, and 13 tumor-related deaths occurred. A short interval to first local recurrence was associated with poor clinical outcome. The rate of local recurrence was independent of histologic grade, but only intermediate and high-grade neoplasms metastasized. The depth of the primary lesion did not influence the incidence of local recurrence. However, in deep-seated neoplasms, the incidence of metastases was higher and the percentage of tumor-related deaths was twice as high as in superficially located lesions, reflecting the fact that deep-seated lesions tended to be higher-grade, larger tumors. Myxofibrosarcoma tends to become progressively higher grade in recurrences, as demonstrated in five cases in our series. The poorly recognized low-grade myxofibrosarcoma is emphasized, as proper diagnosis and treatment and scrupulous follow-up are mandatory to avoid local recurrence and gradual tumor progression to a higher-grade neoplasm that may then metastasize.

Although cardiac sarcomas are rare in comparison to their soft tissue counterparts, they are the second most common type of primary cardiac neoplasm. Of the few hundred cases reported, most has been based on autopsy series. A series of 27 cardiac sarcomas removed at surgery for curative and diagnostic intent were reviewed for clinicopathologic features with correlation to available postoperative follow-up data in 17 patients. There were 6 angiosarcomas, 6 myxofibrosarcomas, 3 malignant peripheral nerve sheath tumors, 3 leiomyosarcomas, 2 synovial sarcomas, 1 epithelioid hemangioendothelioma, 1 chondrosarcoma, 1 osteosarcoma, and 4 poorly differentiated sarcomas. There was a wide age and size range with slight female predilection. There were 20 cases that arose in the atria/pulmonary vessels, 4 in the ventricles, 1 in mitral valve, and 2 in epi/pericardium. There was a slight left predilection. The histologic grade was low in 4, moderate in 3, and high in 20 cases. Six high-grade and 1 low-grade tumors were also treated with adjuvant chemotherapy and/or radiation. In 17 patients with follow-up data, 6 of 12 patients with high-grade tumor died (4 within 5 days of the initial surgery, 1 in 21 months, and 1 in 131 months), and 1 patient with moderate-grade tumor and all 4 patients with low-grade tumor were alive without evidence of disease at the end of follow-up. Tumor grade appeared to be prognostically important in cardiac sarcoma. Long survival was achieved in patients who survived the initial surgery well.