[Clinical pathologic characteristics of extranodal follicular dendritic cell sarcoma].

Objective: To investigate the clinical pathologic characteristics of extranodal follicular dendritic cell sarcoma (FDCS). Methods: We collected 7 cases of extranodal FDCS, HE staining, immunohistochemical study were performed. The V600E mutation of BRAF in 7 cases were detected by real-time PCR and EBER in situ hybridization was performed on 4 cases. Results: Among the 7 cases of FDCS, 5 cases were male and 2 cases were female, the median age was 55 years old, including 4 cases of low-grade FDCS and 3 cases of high-grade FDCS. The tumor location of 2 cases was in mediastinum, the tumor locations of others were in nasopharynx, kidney, lung, rectum and liver, respectively. The results of immunohistochemistry showed that, the tumor cells were diffusely or focally positive for CD21, CD23, CD35, D2-40, EGFR and CXCL13, but negative for S-100, CD68, HMB45, SMA, Desmin, CD117, Dog-1, CD34, CD30, EMA and CK.Five cases were positive for PD-L1 and the its expression in high-grade FDCS were higher than that in low-grade FDCS.Two cases of low-grade FDCS were positive for BRAF V600E, but the BRAF V600E mutation weren't detected in all of 7 cases. The result of EBER in-situ hybridization showed that only the nasopharynx FDCS was positive.The follow-up information of 5 patients were available (7~43 months), 4 patients died and 1 still alive with rectum metastasis. Conclusions: FDCS is a rare malignant disease with relapse and metastatic tendency. The combined applications of the first-line antibodies including CD21, CD23, CD35 and second-line antibodies including D2-40, CXCL13, EGFR are helpful for its diagnosis and differential diagnosis. The high expression of PD-L1 implicates the potential benefit of FDCS patients acquired from immunotherapy.

Follicular Dendritic Cell Sarcoma of Gastrointestinal Tract: an Uncommon Lesion, Commonly Missed.

INTRODUCTION: Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm, accounting for only 0.4% of soft-tissue sarcomas. It shows both nodal and extranodal involvement. Considering the rarity and difficulties in diagnosing this tumor, we consider it very important to share our experience of diagnosing FDCS. Its correct diagnosis cannot be overemphasized as the treatment and prognosis of FDCS are very much different from tumors which come in its differential diagnosis. MATERIAL AND METHODS: We are presenting eight cases of extranodal FDCS in gastrointestinal tract diagnosed at our center in a period of 3 years (Feb 2015 to Feb 2018). Presenting complaints, demographic details, gross description, histologic features, immunostain results, and clinical follow-up were evaluated. RESULTS: Four patients were females and four were males. Tumor ranged in size from 5.5 to 35 cm. In five cases, tumor cells were arranged in storiform and whorling pattern. Lymphocytes were seen sprinkled in between these cells. In one case, lymphocytic infiltrate was extensive. Giant cells and frequent mitoses were noted in two cases. One case showed extensive necrosis. Tumor cells were strongly and diffusely positive for CD21 and CD35. Mean follow up of 11.8 months (range 01 to 24 months) was noted. CONCLUSION: FDCS is a rare tumor having distinct morphology and phenotype which if known can be correctly diagnosed. Therefore, knowledge of its varied location, morphology, and phenotype is very important to correctly diagnose this tumor and to prevent misdiagnosis and mistreatment.

Follicular Dendritic Cell Sarcoma With Indolent T-Lymphoblastic Proliferation Is Associated With Paraneoplastic Autoimmune Multiorgan Syndrome.

Nonclonal expansions of immature T cells outside of the thymus, termed indolent T-lymphoblastic proliferation (iT-LBP), have been identified in rare lymphoproliferative disorders. We report that iT-LBP is a frequent finding in cases of follicular dendritic cell sarcoma (FDCS), and shows an association with paraneoplastic autoimmune multiorgan syndrome (PAMS). We studied 31 cases of FDCS by paraffin immunohistochemistry using antibodies to CD21, CD23, CD35, clusterin, CXCL13, podoplanin, CD3, CD4, CD8, CD20, CD1a, and TdT. Chart review was performed to characterize the clinical behavior including evidence of autoimmune disease. FDCS occurred in a wide variety of nodal and extranodal sites. Fourteen of 31 (45%) cases contained immature TdT-positive T cells; in 5 cases these cells were numerous and present throughout the tumor. Four of these 5 patients with numerous immature T cells developed autoimmune disease, clinically categorized as PAMS and/or myasthenia gravis. PAMS persisted after tumor resection, causing severe morbidity and mortality. These findings suggest that the neoplastic follicular dendritic cells can recruit or foster the proliferation of immature T cells and that these cells may play a role in mediating PAMS. Recognition of iT-LBP in FDCS is important to avoid misdiagnosis as thymoma or T-lymphoblastic lymphoma, and may predict serious autoimmune complications in some patients.

Follicular dendritic cell sarcoma treated with a variety of chemotherapy.

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor derived from follicular dendritic cells. Radical resection is the standard therapy for patients with local disease, but an optimal chemotherapy regimen has not been determined for unresectable disease. We report our experience of an FDCS patient with multiorgan involvement. In the present case, disease was only located in the pancreas initially and radical resection was performed. Multiple metastasis developed after the treatment and several factors that indicated a poor prognosis were observed. The present case had a very poor prognostic disease but survived for a long time with a good performance status because of the multiple chemotherapy regimens, which follow therapeutic strategies for malignant lymphoma and soft tissue sarcoma. As far as we know, this is the first study reporting the indication of bendamustine for FDCS patients.

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.

Clinical and pathological features of head and neck follicular dendritic cell sarcoma.

OBJECTIVES: Follicular dendritic cell sarcoma (FDCS) in the head and neck is uncommon. The etiology, pathogenesis, optimal treatment, and prognosis are not well understood. In this review, we investigated these features to deepen the understanding of the disease. METHODS: We reviewed FDCS in the head and neck in the English language literature through Medline. We analyzed the clinical characteristics, pathologic features, immunophenotypic profile, and treatments of FDCS. RESULTS: Of 137 reported cases of FDCS in the head and neck region, 127 included data on age and gender. Among those, 64 were females and 63 were males. The mean age was 46 years (9-79 years). In the 106 cases with complete follow-up data, fourteen patients (13.2%) had local recurrence. Fourteen patients (13.2%) had distant metastasis. The metastatic site involved the lung, liver, adrenal, rib, vertebral body, and iliac bone. The overall 5-year survival rate was 80.0%. Compared to nodal FDCS and extranodal FDCS, the overall 5-year survival rates were 71.1 and 85.3%, respectively, with no significance (P = 0.42), 0.8% waived treatment, 46.6% received surgery alone, 30.5% received surgery combined with postoperative radiotherapy, 8.4% received surgery combined with postoperative radiotherapy and chemotherapy, 7.6% received surgery combined with postoperative chemotherapy, 3.1% received chemotherapy alone, 2.2% received chemotherapy combined with radiotherapy, 0.8% received radiotherapy alone. CONCLUSIONS: FDCS in the head and neck is rare. There was no difference in the survival between nodal and extranodal FDCS. The optimal treatment was undetermined.

Clinicopathologic characteristics of inflammatory pseudotumor-like follicular dendritic cell sarcoma.

Inflammatory pseudotumor (IPT)-like follicular dendritic cell (FDC) sarcoma is a recently described rare tumor and considered a unique entity, with different histologic appearances and behavior from those of the classical FDC sarcoma. This study analyzed the clinical and pathological findings of two such cases that the authors encountered and 36 previously reported cases identified in the literature. Assessment of all 38 cases showed a slight female predominance (2.2:1) with a median age of 56.5 years. Seventeen patients complained of abdominal discomfort or pain, while fifteen patients had no clinical symptom. Almost all cases occurred in liver (n=20) or spleen (n=17). Except in one case, all patients underwent surgical resection of the tumor alone. Histologic features showed a mixture of chronic inflammatory cells and variable amounts of spindle cells with vesicular nuclei and distinct nucleoli. The tumor cells expressed conventional FDC markers such as CD21 (75%), CD35 (92%), CD23 (62%), clusterin (75%), and CNA.42 (100%). EBV was detected in thirty-five cases (92.1%) by Epstein-Barr virus (EBV)-encoded RNA in situ hybridization, and EBV-latent membrane protein-1 was expressed in 90% of the cases. With a median follow-up of 21 months, 29 patients (85.3%) were alive and well, 4 (11.8%) were alive with disease, one patient (2.9%) died of disease. Only four patients with hepatic tumors underwent recurrence or metastasis after initial treatment. Epstein-Barr virus is thought to play a role in the development of the tumor; however, the pathogenesis of the disease and the origin of tumor cells remain unclear.

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.

Follicular dendritic cell sarcoma: a report of six cases and a review of the Chinese literature.

GOALS: The main purpose of this study is to broaden the clinicopathological spectrum and increase recognition of follicular dendritic cell sarcoma (FDCS) through analysis of the clinical and pathological features of 50 cases. METHODS: The clinicopathological features of total 50 cases of FDCS were analyzed including a review of 44 cases reported in Chinese literature before October 2009 and six original cases from the pathology files conducted by the authors. RESULTS: The youngest patient came under observation in this study is only seven years old. Including the cases contributed by the authors, our literary review indicated that male dominated the tumor cases (M: F = 3: 2). 28 cases (56%) present with this disease in extranodal sites. Tumor cells demonstrated positive staining for the follicular dendritic cell markers CD21 (47/49), CD35 (43/45), CD23 (20/23) and CD68 (23/25). In situ hybridization for Epstein-Barr virus-encoded RNA was performed in 10 cases. Nevertheless, EBV expression was absent in all these cases. The follow-up analysis of all cases shows that 26 (81.2%) patients were alive and disease free; 6 (18.8%) patients were alive with recurrent disease or metastasis; and nobody had died of this disease at the time of last follow-up. CONCLUSIONS: The diagnosis of the FDCS is based on the findings of morphology and immunohistochemistry. The FDCS occurred in China should be viewed and treated as a low-grade sarcoma, and the role of the EBV in the pathogenesis of this tumor is still uncertain. There is a possibility that the tumor might be racial or geographic correlated, because most cases were reported from Eastern Asia area; it's particular the case of the liver or spleen tumor.