Pulmonary Histiocytic Sarcoma: A Case Report and Literature Review

Pulmonary histiocytic sarcoma is a rare, but highly malignant disease. Its low incidence imposes significant difficulties on physicians confronted with affected patients. The reported patient is a 24-year old male with histiocytic sarcoma of the lung. Left lower lobectomy was performed. Histologically, tumor cells had no features of carcinoma. Several entities were raised as differentials: large B or T cell lymphomas, metastatic melanoma, sarcoma, undifferentiated carcinoma, NK cell lymphoma. Immunohistochemically, melanoma, carcinoma, undifferentiated epithelioid sarcoma and also different types of lymphoma were excluded. Therefore, tumors of the histiocytic and dendritic cell lineage had to be considered. Tumors of the dendritic cell lineage were also immunohistochemically excluded, leaving histiocytic sarcoma by exclusion. The patient was followed for six years and six months, with no signs of recurrence of the tumor. Histiocytic sarcomas are tumors of uncertain behavior, with some progressing quickly, and others having a much slower course. As these tumors are rare, there is not much information, although a low number of mitosis might point to a less aggressive course. In the present patient with an unifocal disease, surgical excision was sufficient, without adjuvant radiotherapy and chemotherapy.