Soroush Felezi - Department of Pathology, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran.
Anahita Nosrati - Department of Pathology, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran.

Introduction: Dendritic cells (DC) are accessory arm of immune system involved in antigen presentation processes. Interdigitating dendritic cells (IDCs) are a subpopulation of DCs which are located in secondary lymphoid organs. Interdigitating dendritic cell sarcoma (IDCS) is a rare neoplastic condition in literature. Herein, we report a 55 year-old male case with this malignancy. Patient was referred to Imam Khomeini hospital (Sari, Iran) in August 2018 with right submandibular lymph node mass and a previous history of Basal cell carcinoma (BCC) and Squamous cell carcinoma (SCC). Neither family history nor drug consumption was notable. He underwent complete excision and in H&E –trichrome slide review, the tumor cells were large and pleomorphic with abundant pale, eosinophilic cytoplasm and bizarre, grooved nuclei showing some mitotic figures. A wide immunohistochemical (IHC) panel was performed with following results; positive for (S100, vimentin, desmin and CD68) and negative for (SMA, CD34, BCL2, HMB45, MNF116, P63, CD3, CD30, CD23, Melan A, CD56 and CD45) in tumor cells. Because of patient s physical condition, no chemotherapy was performed, but every 3-month sonographic evaluation is prescribed for him. Currently (Aug 2019) he is doing well without any sign of recurrence or metastasis.

Dendritic cells, Interdigitating dendritic cell sarcoma