Malignant Fibrous Histiocytoma

Research reports on soft tissue sarcoma from Mayo Clinic provide new insights

"A total of 208 exams were reviewed (mean, 8.7 exams per patient) and included all available studies following the start of radiation therapy. Exams were analyzed for the identification of focal signal abnormalities within the surgical bed suggesting local tumor recurrence. Histopathologic correlation was available in nine patients suspected of having local tumor recurrence. Additional information recorded included patient demographics, tumor type and location, radiation type, and dose. The study group consisted of 12 men and 12 women, having an average age of 63 years (range, 39-88 years). Primary tumors were malignant fibrous histiocytoma (n = 13), leiomyosarcoma (n = 6), liposarcoma (n = 3), synovial sarcoma (n = 1), and extraskeletal chondrosarcoma (n = 1). All lesions were high-grade sarcomas, except for two myxoid liposarcomas. Average patient radiation dose was 5,658 cGy (range, 4,500-8,040 cGy). Average follow-up time was 63 months (range, 3-204 months). Focal signal abnormalities suggesting local recurrence were seen in nine (38%) patients. Three of the nine patients with these signal abnormalities were surgically proven to have radiation-induced pseudotumor. The pseudotumors developed between 11 and 61 months following the initiation of radiation therapy (mean, 38 months), with an average radiation dose of 5,527 cGy (range, 5,040-6,500 cGy). MR imaging demonstrated a relatively ill-defined ovoid focus of abnormal signal and intense heterogeneous enhancement with little or no associated mass effect. MR imaging of radiation-induced pseudotumor typically demonstrates a relatively ill-defined ovoid mass-like focus of intense heterogeneous enhancement with little or no associated mass effect. Imaging follow-up or biopsy may be an alternative course of action to surgical re-exploration if this diagnosis is considered," wrote L.F. Moore and colleagues, Mayo Clinic.

The researchers concluded: "The study revealed radiation-induced pseudotumor in 12.5% of patients in our extremity study group, suggesting that radiation-induced pseudotumor may be more prevalent than previously reported."

Moore and colleagues published their study in Skeletal Radiology (Radiation-induced pseudotumor following therapy for soft tissue sarcoma. Skeletal Radiology, 2009;38(6):579-584).

For additional information, contact M.J. Kransdorf, Mayo Clinic, Dept. of Radiol, 4500 San Pablo Rd., Jacksonville, FL 32224, USA.

Publisher contact information for the journal Skeletal Radiology is: Springer, 233 Spring St., New York, NY 10013, USA.

Keywords: United States, Jacksonville, Benign Fibrous Histiocytoma, Chondrosarcoma, Leiomyosarcoma, Liposarcoma, Magnetic Resonance, Malignant Fibrous Histiocytoma, Oncology, Radiation Therapy, Radiology, Sarcoma, Soft Tissue Sarcoma, Synovial Sarcoma, Treatment, Urology, Mayo Clinic.

This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2009, Biotech Business Week via NewsRx.com.