Lymph node involvement in histiocytic sarcoma: A report of two cases with previous misdiagnoses

Histiocytic sarcoma (HS) is an unusual rare but controversial neoplasm. Here, we report two cases of HS initially misdiagnosed as other entities and with initial wrong treatment. The first case was a 29-year-old male with right cervical lymphadenopathy. The patient was misdiagnosed as nodular sclerosis variant of Hodgkin disease. The second case was a 12-year-old male child with axillary and mediastinal lymph nodes. This case was misdiagnosed as tuberculosis. Both these two cases were initially treated according to their primary diagnosis, but without any treatment success. Subsequently, repeat biopsies of these cases were done. Histopathologic examination showed these cases to be HS. The tumor cells were immunoreactive for CD68, CD163, and immunonegative for cytokeratin, epithelial membrane antigen, CD15, CD30, and other markers. Focal positivity of S-100 was noted in one case. Thus, confirmed diagnosis of HS was established. Patients were treated for HS and were kept well in 1-year follow-up period.