New insights inside the interdigitating dendritic cell sarcoma-pooled analysis and review of literature.

Interdigitating dendritic cell sarcoma is a rare haematological neoplasm with high debatable management protocols. The data extracted from 127 case reports published between 1981 and 2018 were analysed. The median age at diagnosis was 58 years with a male to female ratio of 1.65:1. The median OS and PFS of IDCS were 12 and 6 months, respectively, with a disease-specific mortality rate of 36.4%. Two-thirds of patients had a localised disease, while 30% had a disseminated form with 1-year mortality rates of 21.1% and 78.9%, respectively. Twenty per cent of cases were associated with other malignancies. Histologically, the proliferation of large spindle-shaped cells with fascicular growth was described in 84.3% of cases. Based on Cox-regression model, surgical resection was the only treatment modality linked to survival improvement with no recorded survival benefits of radiotherapy and chemotherapy. The 1-year mortality rates in resected and non-resected disease were 17.8% and 63.2%, respectively (P < 0.0001).

Diffuse lesion and necrosis tied to poorer prognosis of interdigitating dendritic cell sarcoma: cases report and a pooled analysis.

Interdigitating dendritic cell sarcoma is a neoplastic proliferation of interdigitating dendritic cells and no therapeutic consensus exists. This study aimed to investigate the prognostic impacts of tumor lesion, cellular atypia, mitosis and necrosis on the interdigitating dendritic cell sarcoma. Case reports and pooled analyses were designed to explore the relationships. One case was a 40-years old man with localized lesion, moderate to notable cellular atypia, 30 mitoses per 10 high-power fields and no necrosis and the progression-free survival was longer than 20 months. The other case was a 62-years old woman with diffuse lesion, notable cellular atypia, less than one mitosis per 10 high-power fields and diffuse necrosis and the progression-free survival was shorter than 1 month. Cellular atypia and mitosis had not any relationship with survival. Compared with localized lesion, diffuse lesion presented a 2.92-fold risk of progression (HR = 2.92, 95% CI 1.01, 8.51) and an 8.79-fold risk of death (HR = 8.79, 95% CI 1.86, 41.64). Diffuse necrosis presented a 4.39-fold higher progression risk (HR = 5.39, 95% CI 1.78, 16.29) and a 5.37-fold higher death risk (HR = 6.37, 95% CI 1.46, 27.86) than focal or no necrosis. Diffuse lesion and diffuse necrosis were indicators of poorer prognosis and the clinical application should be warranted in further studies.

Impact of surgery, radiation and systemic therapy on the outcomes of patients with dendritic cell and histiocytic sarcomas.

BACKGROUND: Neoplasms of histiocytic and dendritic cell origin, including follicular dendritic cell sarcoma (FDCS), histiocytic sarcoma (HS) and interdigitating dendritic cell sarcoma (IDCS), are extremely rare, and data on their natural history and treatment outcomes are sparse. We evaluated the impact of surgery, radiation and systemic therapies on overall survival (OS). METHODS: We conducted a retrospective chart review of patients with FDCS, IDCS and HS treated at Memorial Sloan Kettering Cancer Center between 1995 and 2014. RESULTS: We identified 31, 15 and 7 patients with FDCS, HS and IDCS, respectively. Median age was 48.7, 42.3 and 58.8years for FDCS, HS and IDCS, respectively. Only a slight disparity in gender distribution existed for FDCS and HS; however, IDCS predominantly affected males (6:1). The most common sites of presentation were abdomen and pelvis (42%), extremities (33%) and head and neck (57%) for FDCS, HS and IDCS, respectively. At diagnosis, 74%, 40% and 86% of patients presented with localised disease in FDCS, HS and IDCS, respectively. Patients with localised disease had significantly improved OS than those with metastatic disease in FDCS (P=0.04) and IDCS (P=0.014) but not in HS (P=0.95). In FDCS and HS, adjuvant or neo-adjuvant therapy was not associated with improved OS compared with observation. In IDCS, surgery alone provided a 5-year overall survival rate of 71%. CONCLUSIONS: Adjuvant or neo-adjuvant treatment in FDCS and HS did not affect OS. Patients with IDCS had an excellent outcome with surgery. In the metastatic setting, chemotherapy and small molecule inhibitors may provide benefit.

Interdigitating and follicular dendritic cell sarcomas: a SEER analysis.

OBJECTIVES: Follicular dendritic cell sarcoma (FDCS) and interdigitating dendritic cell sarcoma (IDCS) are rare neoplasms of dendritic cell origin. Because of the rarity of these diagnoses, optimal management is unclear. METHODS: In this study, we reviewed the data on FDCS and IDCS available in the Surveillance, Epidemiology, and End Results database. Fifty-four patients with FDCS and 20 with IDCSs were identified between the years 2001 and 2008. RESULTS: Median follow-up was 28 months. Sixty-one percent of FDCS patients and 55% of IDCS patients presented with localized disease. Of the FDCS patients with localized disease, 31/33 (94%) underwent surgical resection. Fifty-five percent (6/11) of localized IDCS patients underwent surgical resection. Radiation therapy was given to 30% of patients. Overall survival was significantly better for patient with FDCS compared to those with IDCS. Median survival was 35 months in patients with IDCS and was not reached in patients with FDCS. There was a trend toward improved overall survival in FDCS patients with localized disease. IDCS patients with localized disease had a significantly improved overall survival compared with those with distant disease with 2-year overall survival of 72% versus 33%, respectively (P = 0.05). CONCLUSIONS: These data demonstrate that most patients with localized disease are treated similar to a soft tissue sarcoma with primary surgical resection with or without radiation. No chemotherapy data were available in the Surveillance, Epidemiology, and End Results database. The role of chemotherapy and radiation therapy remains unclear.