Inflammatory malignant fibrous histiocytoma of the ovary producing interleukin-6: A case report

Objective. Inflammatory malignant fibrous histiocytoma (IMFH) is composed of fibroblastic and histiocytic elements with a marked inflammatory cell infiltrate. The authors examined the case of a 43-year-old woman with IMFH of the ovary. Methods. The serum interleukin-6 (IL-6) levels were examined and immunohistochemical analysis of the tumor was performed using monoclonal antibodies against lysozyme, α 1-antitripsin, vimentin, and IL-6. Results. The patient had marked general inflammatory reactions of fever (38.0°C), leukocytosis with 78.3% neutrophils, elevated CRP (23.5 mg/dl), and accelerated ESR (166 mm/h). The serum IL-6 concentration was 499 pg/ml. The right ovary was occupied by the solid tumor, composed of both fibrous and histiocytic elements with a marked inflammatory cell infiltrate. These inflammatory reactions disappeared after surgical resection and recurred when the tumor reappeared. The immunohistochemical staining of lysozyme, α 1- antitrypsin, vimentin, and IL-6 was localized to the malignant cells, suggesting their histiocytic origin. Conclusions. This is the first case of IMFH of the ovary producing IL-6. Expression of IL-6 in the IMFH may account for both the local and the systemic inflammatory effects of tumors with these morphological features.