Histiocytic Sarcoma Diagnosed on Repeat Biopsy of Multifocal Extranodal Tumors.

Abstract

Introduction: Histiocytic sarcoma (HS) is a rare malignant disease with a poor prognosis and unknown pathogenesis. In addition, this disease is difficult to diagnose due to the wide variety of diseases to be differentiated from it.

Case presentation: A 37-year-old woman with right-sided chest pain was referred to our hospital. Computed tomography (CT) revealed a 30-mm mass with osteolytic changes in the right eighth rib. Further examination revealed a rib mass, right renal mass, anterior mediastinal nodule, bilateral pulmonary nodules, and suprasellar nodule. A needle biopsy of the rib mass revealed granuloma with histiocytes. A subsequent needle biopsy of the right renal mass revealed similar findings without evidence of malignancy. The imaging findings suggested malignant disease; therefore, wedge resection of the upper lobe of the right lung and biopsy of the mediastinal mass were performed under general anesthesia. HS was diagnosed based on the immunostaining results.

Conclusions: For the treatment of HS, early intervention is said to contribute to a prolonged prognosis. In order to provide appropriate therapy, HS should be included in the differential diagnosis for multifocal extranodal tumors.