Increased metastasis of malignant fibrous histiocytoma in patients with chronic lymphocytic leukemia and non-Hodgkin lymphoma

OBJECTIVE: To further understand the characteristics and behavior of malignant fibrous histiocytoma (MFH) in the clinical setting of chronic lymphocytic leukemia (CLL) or non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS: The patient database of MHF diagnosed at our institution from January 1, 1976, to December 31, 2008, was reviewed. For each MFH case with prior NHL or CLL, 3 matched controls from the same cohort without prior CLL or NHL were randomly selected. A retrospective chart review collected patient data, including sex; age; pathologic confirmation of MFH; tumor grade, size, and location; time since MFH diagnosis; history of chemotherapy or irradiation; treatment of MFH; recurrence; metastasis; and death. The Kaplan-Meier method was used to estimate overall survival, survival free of recurrence, and survival free of metastasis. Cox proportional hazards models were fit to evaluate associations between case status and outcomes. RESULTS: Fifteen MFH cases with prior NHL or CLL were identified. Cases had frequent bone (n=7 [47%]) and cutaneous (n=5 [33%]) involvement. Five cases (33%) had previous irradiation, 6 (40%) had metastases, and 4 (27%) had recurrence. Overall survival and survival free of recurrence were not significantly different between the cases and controls (5-year overall survival, 49.9% and 58.7%; 12-month survival free of recurrence, 79.4% and 90.3%). However, cases were significantly more likely than controls to have metastasis (hazard ratio, 3.79; 95% confidence interval, 1.22-11.79; P=.02). In addition, survival free of metastasis at 12 months was 65.2% and 90.7%, respectively. CONCLUSION: In the presence of CLL or NHL, MFH seems to behave more aggressively, suggested by the increased likelihood of metastases compared with controls without prior CLL or NHL. However, overall survival does not appear to be worse in cases of MFH and CLL or NHL than in MFH alone.