Rare co-occurrence of tonsillar follicular dendritic cell sarcoma and schizophrenia: A comprehensive study

This study investigated the infrequent occurrence of tonsillar follicular dendritic cell sarcoma (FDCS) co-existing with schizophrenia, presenting a comprehensive examination of clinical, pathological, and literature aspects. A systematic literature review was conducted, focusing on articles related to "schizophrenia" and "sarcoma," with in-depth analysis of included case reports. Clinical data, pathological findings, and patient follow-up information were collected and synthesized. The study detailed a rare case of FDCS in the tonsil concurrent with schizophrenia, providing insights into diagnosis, treatment, and follow-up. A literature review of combined FDCS in the tonsil and schizophrenia cases highlighted their clinical and pathological characteristics. Eight case reports encompassing 11 patients diagnosed with sarcoma and schizophrenia were included. Surgical resection was the preferred primary treatment, while chemotherapy was suggested for recurrences. Instances of co-occurring FDCS and schizophrenia were exceptionally limited, with tonsillar FDCS being particularly uncommon. The coexistence of tonsillar FDCS and schizophrenia was an exceptionally rare condition, posing diagnostic and therapeutic challenges. This study contributed valuable insights into clinical and pathological practice through a systematic review, underscoring the significance of early diagnosis and comprehensive management.

Case report: EBV-positive epithelioid follicular dendritic cell sarcoma with CD30 expression: a highly challenging diagnosis

Introduction

Follicular dendritic cell sarcoma (FDCS) is a rare tumor entity with a wide range of anatomical sites and strong heterogeneity in morphology and immunohistochemistry, making it highly susceptible to misdiagnosis. There are two types of FDCS: conventional FDCS and EBV+ inflammatory FDCS. It is currently suggested that the former has nothing to do with EBV infection. Moreover, they have distinctively different clinicopathological characteristics.

Case description

A 69-year-old male patient was admitted to our hospital after 4 months of progressive enlargement of the neck mass. Positron emission tomography/computed tomography (PET/CT) examination showed multiple enlarged lymph nodes in the body. After cervical lymph node excision and biopsy, it was found that the tumor cells were epithelioid and diffusely expressed EBER and CD30. It was initially diagnosed as poorly differentiated cancer and lymphoma. In subsequent differential diagnosis, we found that it strongly stained CD21 and CD23, which was approved the diagnosis of EBV+ FDCS.

Conclusion

Epithelioid FDCS is very rare. EBV-positive FDCS with abnormal expression of CD30 has not been reported. Whether EBV also plays an important role in conventional FDCS requires more cases to be verified. Our case provides valuable research clues for further understanding the pathological characteristics of this tumor entity.

Clinicopathologic profile of intra-abdominal follicular dendritic cell sarcoma: A study of three cases with a literature review

Follicular dendritic cell sarcoma (FDCS) is a rare tumor, which mainly originates from follicular dendritic cells (FDCs) in the lymph nodes. Sometimes FDCS can arise from outside the lymph nodes. FDCS is an extremely rare malignant tumor in intraperitoneal or retroperitoneal tissue. We gathered the detailed clinical data of three patients diagnosed with FDCS in the abdomen. The clinical observations and histopathologic and immunohistochemical features of FDCS were analyzed. The patients included two men and one woman aged 55 ~ 61 years old. The mesentery of the small intestine and colon was involved in case 1, spleen in case 2, and retroperitoneal tissues in case 3. Two patients presented with abdominal masses, and one presented with no obvious symptoms. Histology showed ovoid to spindle neoplastic cells arranged in fascicles and storiforms with inflammatory infiltrate as well as whorled patterns in some areas. Immunohistochemical staining was positive for CD21, CD23, CD35, and SSTR2. FDCS exhibits no characteristic clinical manifestations. Morphologically, FDCS can have overlapping features with many other entities, leading to misdiagnosis. The use of histopathology supplemented with FDC markers, such as CD21, CD23, and CD35, is useful for diagnosis and differential diagnosis.

A Rare Case of Primary Follicular Dendritic Cell Sarcoma of the Kidney

The objective of this case report is to describe a rare case of primary follicular dendritic cell sarcoma (FDCS) of the kidney. FDCS is a rare soft tissue malignancy that most often presents intranodally with lymphadenopathy of the neck, mediastinum, and axilla. One-third of cases present extranodally and most commonly affect the liver, lung, and tonsils. To date, there have been few reports of retroperitoneal FDCS and, to the best of our knowledge, only two other reported cases with primary renal involvement. We present a 56-year-old female with end-stage renal disease on hemodialysis who presented to the hospital with a hypertensive emergency. Computed tomography (CT) of the abdomen was obtained revealing a left-sided renal mass and she subsequently underwent left radical nephrectomy. The pathologic features of the mass revealed oval to spindle cells with eosinophilic cytoplasm, dispersed vesicular chromatin, and small nucleoli found arranged in fascicles, whorls, and storiform patterns with occasional multinucleate forms. The neoplastic cells were immunoreactive to vimentin and expressed cell markers for CD23, CD35, and CD68. These features confirmed a final pathologic diagnosis of primary FDCS of the kidney. To our knowledge, this is the third case of primary renal FDCS reported in the literature. Extranodal FDCS is rare but does occur and needs to be on the differential diagnosis if pathologic features point to its diagnosis.

Extranodal Follicular Dendritic Cell Sarcoma of the Head and Neck Region: A Clinicopathological Study of 7 Cases

Background. Follicular dendritic cell (FDC) sarcoma is a rare neoplasm arising from follicular dendritic cells (FDCs). It can be nodal or extranodal. Histological diagnosis of extranodal FDC sarcoma in the head and neck region is challenging and a significant percentage are misdiagnosed. Objectives. To report clinicopathological features of head and neck extranodal FDC sarcoma cases and discuss differential diagnoses. Methods. Seven head and neck extranodal FDC sarcomas were retrieved and clinicopathological features were noted. Results. Two tumors each involved parapharyngeal space and tonsil while remaining cases involved the parotid, soft tissue of neck and oropharynx. Age range was 12 to 79 years (mean and median age were 40 and 44 years respectively) and there was a male predilection (6 males: 1 female). All showed spindle to ovoid cells arranged in fascicles, whorls and/or storiform pattern. Mitoses ranged from 3 to 20/mm2. All tumors expressed CD21 and CD23. Two patients died of their disease at 9 and 16 months. Both had tumors larger than 5 cm with ≥10 mitoses/mm2. Three patients were alive at 12, 44 and 184 months. Conclusions. There was a distinct male predominance in our cohort. FDC sarcoma should be included in the differential diagnosis of spindle cell extranodal neoplasms in the head and neck with a whorled growth pattern and intratumoral lymphocytes. Head and neck region tumors show similar clinicopathologic characteristics as their counterparts at other locations with potential for aggressive behavior especially in tumors greater than 5 cm in size and with high mitotic rates.

Favorable response to PD-1 inhibitor plus chemotherapy as first-line treatment for metastatic follicular dendritic cell sarcoma of the spleen: a case report

Follicular dendritic cell sarcoma (FDCS) is an uncommon low-grade malignant sarcoma. For localized FDCS, surgery is the most commonly recommended therapy option. However, there is no standard treatment protocol for metastatic FDCS. Here, we present a 68-year-old female with primary spleen FDCS who had multiple peritoneal metastases. She was treated with sintilimab (PD-1 inhibitor) plus chemotherapy (epirubicin plus ifosfamide) as first-line treatment achieving partial response (PR) and a relatively long progression-free survival (PFS) of 17 months. This case suggests that PD-1 inhibitor plus chemotherapy as first-line therapy seem to be a promising treatment option for metastatic FDCS.

Epstein-Barr Virus-Positive Inflammatory Follicular Dendritic Cell Sarcoma Presenting as a Colonic Polyp: Report of a Case with a Literature Review

Background: Follicular dendritic cell (FDC) sarcoma is an uncommon mesenchymal origin neoplasm derived from the abnormal proliferation and differentiation of FDCs. Epstein‒Barr virus-positive inflammatory follicular dendritic cell sarcoma (EBV+ iFDCS), which used to be known as the inflammatory pseudotumour (IPT)-like variant, occurs exclusively in the liver and spleen and has rarely been reported in the gastrointestinal tract. Case study: Here, we report a case of a 52-year-old woman with a special family history undergoing a routine physical examination. The colonoscope revealed an approximately 18 mm transverse colonic polyp, and the endoscopic polypectomy was performed. Microscopically, the excised polypoid mass was composed predominantly of inflammatory cells scattered with atypical ovoid to spindle tumor cells. Interestingly, there was a remarkable infiltration of IgG4+ cells. Immunohistochemistry showed that the tumor cells were positive for CD21, CD23 and CD35. EBV-encoded mRNA (EBER) in situ hybridization also gave positive signals. These histopathology features supported the diagnosis of EBV+ iFDCS. The patient was free of disease over 1-year follow-up. Conclusion: Identification of the potential pathogenesis sites of EBV+ iFDCS in extra-hepatosplenic regions is necessary for correct and timely diagnosis, and we consider it very meaningful to share our experience of diagnosing this tumor type. Furthermore, we summarize the clinicopathological features of EBV+ iFDCS presenting as a colon polyp after a thorough review of the literature.

Mediastinal Follicular Dendritic Cell Sarcoma With Underlying Sjogren's Syndrome

Follicular dendritic cells help advance B-Cells in becoming memory B-Cells or antibody-producing plasma cells in the light zone, or undergo additional affinity maturation in the dark zone. Follicular dendritic cell sarcoma (FDCS) is an extremely rare soft tissue malignancy derived from follicular dendritic cells. Autoimmune disease increases the risks for the development of hematological malignancies. To the best of our knowledge, there are few cases of FDCS development in the setting of underlying Sjogren's syndrome (SS). Therefore, in this report, we present a novel case of FDCS associated with new-onset SS. In SS, the follicular dendritic cells are organized within germinal centers within the glands it infiltrates and is involved in B-Cell development. Because FDCS is derived from follicular dendritic cells, our report postulates that the unregulated follicular dendritic cell proliferation that may occur in SS could increase the risk for FDCS. Due to this possible connection observed in our patient, we highlight FDCS as a differential diagnosis when considering soft tissue cancers. We urge additional research to outline and explore the possible pathologic link between SS and FDCS.

Fine needle aspiration cytology of follicular dendritic cell sarcoma of the stomach masquerading as gastrointestinal stromal tumor: A case report of a unique entity with emphasis on cytomorphology

Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm, postulated to arise from follicular dendritic cells, with approximately 343 reported cases. Less than 100 cases of FDCS were in the gastrointestinal tract, with only four cases described in the stomach, none of them diagnosed on fine needle aspiration (FNA) cytology. We report here the first case of FDCS of the stomach diagnosed on FNA. Our patient is a 31-year-old male who presented with several years history of intermittent abdominal pain prompting occasional emergency-room visits. Imaging showed a 10.6 cm mass arising from the stomach, concerning for gastrointestinal stromal tumor. FNA cytology was performed using five passes with a 22-gauge needle. The smears were moderately cellular consisting of sheets and large, loosely cohesive clusters of ovoid to spindle cells with indistinct cytoplasmic borders and abundant cytoplasm, peppered with numerous small mature lymphocytes. The nuclei of the tumor cells were oval with finely granular chromatin with frequent nuclear grooves, pseudoinclusions, and easily recognizable mitotic figures. The tumor cells were positive for FDCS markers (CD21, CD23, and CD35).

Follicular dendritic cell sarcoma of the nasopharynx: a case report and literature review

Follicular dendritic cell sarcoma (FDCS) of the nasopharynx is a rare malignant tumor that has been described in only a few case reports, and its differential diagnoses include diverse clinicopathologic entities. FDCS is often initially misdiagnosed, especially when examining small biopsy specimens. We herein report a case of FDCS arising in the nasopharynx that was initially misdiagnosed as a nerve sheath tumor. A 44-year-old woman presented with persistent obstruction of the left nasal cavity and underwent an excisional biopsy. The specimen demonstrated morphologic and immunohistochemical features of FDCS. In situ hybridization for Epstein–Barr virus-encoded RNA was negative. The patient was treated with chemotherapy and radiotherapy. The sarcoma recurred near the original site more than 3 years after the initial treatment and was completely resected. At the time of this writing, the patient had remained disease-free for 1 year after resection. This case is being reported to improve the clinical recognition of FDCS.

Response of Tonsil Follicular Dendritic Cell Sarcoma to Multimodal Treatment Including Pembrolizumab: A Case Report and Literature Review

Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm that was classified by the World Health Organization (WHO) under histiocytic and dendritic cell neoplasms in the 2016 revision. Considering the rarity of this tumor, there is no standardized treatment. It is usually treated by complete surgical resection. Adjuvant chemotherapy and radiotherapy are alternative methods. Immune checkpoint inhibitors (ICIs) represented by the programmed death receptor 1/programmed death ligand 1 (PD-1/PD-L1) antibody have achieved significant clinical benefits in a variety of solid tumors. However, reports on the treatment of FDCS with ICIs are rare. FDCS often expresses high levels of PD-L1, which provides a rationale to use immunotherapy in cases of FDCS. Here, we present a 51-year-old Filipino-Chinese man with FDCS who was treated with multimodal treatment, including the PD-1 inhibitor pembrolizumab and achieved a relatively long disease-free survival of 24 months. This case emphasizes that the application of ICIs under the guidance of NGS technology seems to be a meaningful treatment option for patients with FDCS.

Hepatic Follicular Dendritic Cell Sarcoma with Epithelioid Morphology: Histopathologist's Perspective

Follicular dendritic cell (FDC) sarcoma is an uncommon tumor of the liver with only 30 previous cases reported in the English literature. Histopathological examination is the gold standard for the diagnosis of FDC sarcoma although the diagnosis is often missed because of its rarity. It usually presents with spindle-cell morphology although epithelioid/biphasic morphology is also well-known. This morphological variation can also pose a diagnostic challenge. We discuss a case of unresectable hepatic FDC sarcoma in an adult male who was diagnosed in core biopsy. We highlight the relevant histomorphological differentials and diagnostic approaches to FDC sarcoma in this anecdote.

Follicular dendritic cell sarcoma

Follicular dendritic cells (FDC) are mesenchymal-derived dendritic cells located in B-follicles where they play a pivotal role in triggering and maintaining B-cell adaptive immune response. In 1986 Dr. Juan Rosai first reported a series of neoplasms showing features of FDC and defined it as Follicular Dendritic Cell Tumor, subsequently renamed as "sarcoma" (FDCS). In its seminal and subsequent articles Rosai and colleagues highlighted the heterogeneous microscopic appearance of FDCS and its immunohistochemical and ultrastructural features.

FDCS mostly occurs in extranodal sites (79.4% of cases) and lymph nodes (15.1%); in about 7%-10% of cases it is associated with hyaline-vascular Castleman disease. Given its significant growth pattern and cytological variability, FDCS can be confused with various neoplasms and even inflammatory processes. The diagnosis requires the use of a broad spectrum of FDC markers (e.g. CD21, CD23, CD35, clusterin, CXCL13, podoplanin), particularly considering that tumor antigen-loss is frequent. The inflammatory-pseudotumor-like (IPT-like) variant of FDCS, in addition to its peculiar histopathological and clinical features, is characterized by positivity of tumor cells for Epstein-Barr virus, representing a diagnostic requisite.

No distinctive genetic and molecular anomalies have been identified in FDCS. It often carries an aberrant clonal karyotype and chromosomal structural alterations, frequently involving onco-suppressor genes. Direct or next generation sequencing showed alterations on genes belonging to the NF-κB regulatory pathway and cell-cycle regulators. In contrast to hematopoietic-derived histiocytic and dendritic cells tumors, FDCS typically lacks mutations in genes related to the MAPK pathway.

FDCS recurs locally in 28% and metastasizes in 27% of cases. Extent of the disease, surgical resectability and histopathological features are significantly associated with the outcome. IPT-like FDCS behaves as an indolent tumor, even if it often recurs locally over years.

Complete surgical excision is the gold standard of treatment. Data on targeted therapies (e.g.: tyrosine kinase inhibitors) or immune checkpoint inhibitors are very limited and responses are variable. A better understanding of the molecular drivers of this tumor may lead to potential new therapeutic strategies.

Follicular Dendritic cell sarcoma of caecum in a young boy presenting as Intussusception

Background

Follicular dendritic cell sarcoma (FDCS) is a rare tumor derived from follicular dendritic cells (FDC) occurring in lymph nodes and extranodal sites. It is usually regarded as an indolent tumor with a tendency of local recurrence but a low risk of metastasis. Common extranodal sites are liver, lung, tonsil, spleen, soft tissue, and mediastinum. Extranodal FDCS of gastrointestinal tract (GIT) is exceedingly rare, with just 36 cases reported in the literature.

Methods

We report an unusual case of FDCS of caecum in a 13-year-old boy who presented as intussuception. On histology, it posed a diagnostic challenge for us. An inconclusive initial immunohistochemistry (IHC) lead us to suspect FDCS which was confirmed by FDC markers.

Conclusions

The diagnosis of FDCS at extranodal site like GIT is all the more challenging because of its rarity, morphologic heterogeneity, and lack of awareness.

Extranodal Follicular dendritic cell sarcoma presenting as a rectal polyp: An entity overlooked by its differentials

Extranodal follicular dendritic cell sarcoma (ENFDCS) is a rare hematolymphoid tumor, masquerading as soft tissue sarcoma on initial histological examination. So, for its confirmation, the application of immunohistochemistry (IHC) is of paramount importance. Over the years there has been a major shift in the demography of follicular dendritic cell sarcoma (FDCS), with a rise in the number of extranodal cases. Herein we report a case of ENFDCS presenting as a rectal polyp, who had a history of intermittent bleeding per rectum and passage of fleshy mass while defecation. As these tumors share an overlapping morphology with other spindle cell tumors and can occur at unpredictable locations, they pose a diagnostic challenge, especially for young pathologists.

Unexpected Favorable Outcome to PD-1 Antibody Plus Lenvatinib in a Patient With Recurrent Intestinal Follicular Dendritic Cell Sarcoma: A Case Report and Literature Review

Background

Follicular dendritic cell sarcoma (FDCS) is an uncommon malignant cancer, and there is no standard treatment to date. Resection followed by adjuvant chemotherapy or radiation is considered the most commonly used strategy for treatment. However, the treatment for patients who have progressed after systemic treatment is more controversial.

Case summary

In this case report, we describe a 57-year-old man with primary small intestine FDCS where surgery and second-line systemic chemotherapy failed. After disease progression (PD), the patient received sintilimab plus lenvatinib as third-line treatment and achieved a progression-free survival (PFS) with 7 months.

Conclusion

This is the first report of a FDCS patient treated with immune checkpoint inhibitors (ICIs) and antiangiogenic agents, sintilimab and lenvatinib, as third-line therapy. Our case provides a potential therapeutic option for patients with FDCS who progressed after multiline therapy.

Intra-muscular follicular dendritic cell sarcoma in the thigh: A case report

RATIONALE

Follicular dendritic cell sarcoma (FDCS) is an intermediate-grade malignancy originating from follicular dendritic cells. Nodal FDCS is the most common type, meaning that the extranodal type may not be recognized and could be easily misdiagnosed. Reported extranodal sites include the head and neck, retroperitoneum, spleen, liver, and gastrointestinal tract. FDCS in the soft tissue is extremely rare.

PATIENT CONCERNS

A 75-year-old male presented with complaints of a localized swelling and intra-muscular soft tissue mass in the left upper thigh.

DIAGNOSIS

The present tumor consisted of fascicular or vague storiform-arranged spindle cells with less pleomorphism and many lymphoid aggregates. Tumor cells were positive for CD21, CD35, CD68, vimentin, and EGFR. Intra-muscular FDCS was confirmed by immunohistochemical studies.

INTERVENTIONS

The patient received a wide marginal excision, followed by adjuvant radiotherapy.

OUTCOMES

Symptomatic improvements were achieved and no subsequent relapses were observed.

LESSONS

If the tumor arises in the extranodal sites, especially in the soft tissue, it is difficult to include FDCS in the differential diagnosis. When the immunoprofile is not consistent with that of common spindle cell tumors, immunostaining for follicular dendritic cell markers such as CD21, CD23, and CD35, as well as further immunohistochemistry for D2-40, CD68, EGFR, Epstein-Barr virus, and BRAF can be helpful for the diagnosis and subtyping of FDCS. To the best of our knowledge, the present case is the first case of intramuscular FDCS.

Follicular dendritic cell sarcoma of the cervical lymph node diagnosed on fine needle aspiration cytology

Follicular dendritic cell sarcomas (FDCS) are rare tumours of lymph nodes and extranodal tissues which are grouped with the histiocytic and dendritic cell neoplasms. The diagnosis is usually made after thorough clinical and pathological examination with immunohistochemical analysis. Difficulties persist in diagnosing FDCS on cytological preparations. We report herein a case of a 57-year-old female who presented with a right neck mass of 5 months duration. Computed Tomography (CT) imaging of the neck reported a necrotic right level IIb lymph node and asymmetric fullness of the right palatine tonsil. Fine needle aspiration (FNA) biopsy revealed numerous spindle, oval and stellate neoplastic cells, arranged singly and in syncytia with moderate nuclear pleomorphism, vesicular chromatin pattern, and prominent nucleoli, sprinkled with small lymphocytes. The tumour cells were strongly diffusely positive for CD21, CD23, and D2-40 immunostaining on cell bock sections, but were negative for CD1a and CD34, supporting the diagnosis of FDCS. Follow-up surgical pathology on the resection showed histopathological features and an immunohistochemical profile consistent with FDCS.

Primary Follicular Dendritic Cell Sarcoma of Urinary Bladder

Follicular dendritic cell sarcoma is a rare malignant mesenchymal neoplasm composed of follicular dendritic cells. A subset of cases can be found at extranodal sites. Only 2 follicular dendritic cell sarcomas were previously reported in the urinary bladder. We report a follicular dendritic cell sarcoma that involved the urinary bladder of an 81-year-old woman, who presented with painless gross hematuria. The neoplasm was composed of large epithelioid cells with atypical nuclei, admixed with inflammatory cells. On immunohistochemistry, the neoplastic cells were reactive only for CD21, CD35, and vimentin. The tumor was considered unresectable due to its large size and proximity to the iliac vessels and the patient was treated with bortezomib, cyclophosphamide, and dexamethasone. Although a full course of chemotherapy was not completed due to adverse side effects, the tumor was reduced in size. A subsequent involved-field radiotherapy was performed. Three years postdiagnosis and 2 years after the radiotherapy treatment, a recurrent tumor was identified on imaging in the left posterolateral bladder wall. However, at that time the patient was found to have a newly developed advanced colonic adenocarcinoma. Three and a half months later she developed a bowel perforation and died.

Primary Follicular Dendritic Cell Sarcoma of Breast: 2 Further Cases with Review of the Literature

Follicular dendritic cell sarcoma (FDCS) is a tumor derived from antigen-presenting cells and can occur within lymphoid tissue or at extranodal sites. FDCS of the breast is remarkably rare, with only 4 cases previously reported in literature. FDCS appears grossly as a well-circumscribed, firm mass with a grey-yellow surface, areas of necrosis, and histologically comprises of spindled, oval, or epithelioid cells with intensely eosinophilic cytoplasm. Immunohistochemistry plays a key role in its diagnosis. Here we describe 2 cases of FDCS of breast in 2 women aged 70 and 35 years old, who presented with a palpable lump in the breast. One patient had concomitant invasive ductal carcinoma as well. We highlight the key histopathological and immunohistochemical features of the tumor.

Follicular dendritic cell sarcoma of the tonsil: case report and review of literature

OBJECTIVE

To explore the clinicopathologic features, immunophenotype, differential diagnosis, and prognosis of tonsil follicular dendritic cell sarcoma (FDCS).

METHODS

In the Department of Pathology, the affiliated Yantai Yuhuangding Hospital of Qingdao University, in 2019, a case of tonsil FDCS was diagnosed and retrospectively analyzed to summarize its clinical and pathologic characteristics. Relevant literature was reviewed.

RESULTS

The patient was a 71-year-old man. The tumor occurred in the right tonsil with a maximum diameter of 3.5 cm. Microscopically, the tumor cells were spindle-shaped or oval-shaped, arranged in bundles or swirls, and some areas formed concentric circles around blood vessels. Small lymphocytes were distributed in the background. The nucleus was oval-shaped or round, with nuclear chromatin and small central nucleoli. Mitoses were up to 5/10 HPF at the highest. Immunohistochemistry showed positive expression of CD21, CD23, CD68, vimentin, and D2-40 in tumor cells, and Ki67 proliferation index was about 20%. CXCL13 was positive only in scattered background lymphocytes. In situ hybridization for EBER was negative. After surgical resection of the tumor, without radiotherapy or chemotherapy, the patient has been followed up for 4 months until now, without recurrence or metastasis.

CONCLUSION

FDCS is a rare tumor, especially in extranodal sites. The pathogenesis, treatment and prognosis of FDCS still need further exploration.

Clinicopathological characteristics of extranodal follicular dendritic cell sarcoma: A report of two cases

Follicular dendritic cell sarcoma (FDCS) is an extremely rare tumor, which mainly originates from FDCs in the lymph nodes. Sometimes FDCS can arise from outside the lymph nodes due to the existence of acquired lymphoid tissue, which becomes the histological basis of the tumor. The diagnosis of FDCS, particularly extranodal FDCS, presents a challenge for pathologists and hematopathologists. The present study presents two cases of extranodal FDCS based on clinical features and histomorphology. Soft tissue of the chest wall was involved in case 1 and right tonsil tissue in case 2. Case 1 underwent surgery, and was in good health post-operatively. During the 5-month post-operative follow-up period, the patient was healthy in all respects. Case 2 received surgery combined with radiotherapy, and the follow-up data reported that the patient remained alive, without signs of recurrence or metastasis during the 4-month post-operative follow-up period. Additionally, a total of 102 cases of extranodal FDCS were retrieved from the literature, which were extracted and reviewed carefully. The rates of recurrence, metastasis and mortality were 14.63 (12/82), 17.07 (14/82) and 8.29% (15/82), respectively. The overall survival rates of the 102 cases, showing 2-year total survival rates, were 70%, the same with that of 5-year total survival rates. The 2-year tumor-free total survival rates were 68%, and the 5-year equivalents were 32%. Female patients had a poorer prognosis than male patients (P<0.05). Kaplan-Meier estimation presented no statistically significant differences between disease-free survival rates or overall survival rates and age, tumor size or treatment (P>0.05).

Follicular Dendritic Cell Sarcomas: CT and MRI Findings in 20 Patients

OBJECTIVE. The objective of this study was to assess the imaging features of follicular dendritic cell sarcoma (FDCS) on CT and MRI. MATERIALS AND METHODS. The clinical data and pretreatment findings of 20 patients with pathologically proven FDCS on CT (n = 15), MRI (n = 7), or both (n = 2) were analyzed retrospectively. Tumor location, number, size, morphology, attenuation or signal intensity, margin, presence of metastases, and contrast enhancement were evaluated. RESULTS. FDCS originated from lymph nodes (n = 6) or a variety of extranodal sites (n = 14). The tumors were typically solitary and well-circumscribed. Extranodal lesions (mostly in the abdomen or mediastinum with mean diameter, 11.8 cm) were larger than nodal lesions (mean diameter, 6.5 cm). Nodal-type cases presented with homogeneous masses on CT and MRI. However, on CT, all extranodal tumors (n = 12) showed heterogeneous attenuation, of which 91.7% (11/12) contained areas of lower attenuation because of internal necrosis and 50.0% (6/12) showed calcifications. On MRI, primary hepatic or splenic tumors (n = 3) also appeared as large heterogeneous masses. Seven patients (35.0%) had advanced-stage disease, and intraabdominal extranodal cases were more likely to have regional lymphadenopathy (n = 4) and distant metastases (n = 5). Hypervascularity was seen in 90.0% (18/20) of patients and progressive enhancement was seen in 11 (78.6%) of 14 tumors with multiphase imaging. CONCLUSION. FDCS is a rare, mostly solitary, well-delineated malignancy. A nodal-type FDCS typically presents as a small homogeneous mass, whereas an extranodal FDCS in the mediastinum or abdomen manifests as a large heterogeneous mass with internal necrosis and calcifications accompanied by regional lymphadenopathy. Hypervascularity and progressive enhancement can be seen in the majority of tumors.

Metastatic follicular dendritic cell sarcoma treated with gemcitabine plus docetaxel with an outstanding survival: A case report and review of literature

Follicular dendritic cell sarcoma responded dramatically to chemotherapy with gemcitabine and docetaxel.

Multidisciplinary diagnosis and treatment of recurrent follicular dendritic cell sarcoma in abdomen: A case report

RATIONALE

Follicular dendritic cell sarcoma (FDCS) is a rare malignant tumor derived from follicular dendritic cells, and is often associated with Castleman disease. Here we present a rare case of paraneoplastic pemphigus (PNP) with FDCS which required multidisciplinary approach for the diagnosis and treatment.

PATIENT CONCERNS

A 28-year-old Chinese female had FDCS recurrence, and primary clinical manifestation was PNP.

DIAGNOSES

PNP with FDCS.

INTERVENTIONS

The patient received gamma globulin infusion, took anlotinib, and underwent plasma exchange therapy.

OUTCOMES

The skin lesions recovered and there was no evidence of tumor recurrence.

LESSONS

The diagnosis and management of PNP with FDCS require close cooperation among surgeons, dermatologists, hematologists, otolaryngologists, oncologists, radiologists, pathologists, and respiratory doctors. The interesting clinical manifestations of this patient provide a multifaceted approach to the investigation of the interactions among FDCS, Castleman disease, and PNP.

Not always 'squame': The rare entity of follicular dendritic cell sarcoma of the tonsil presenting with cervical nodal metastases

Although squamous cell carcinoma accounts for the overwhelming majority of head and neck malignant neoplasms, extranodal follicular dendritic cell sarcoma (FDCS) of the pharyngeal region can have a similar clinical presentation. The histopathological features of this rare entity have been described and emphasised in the literature. We present the case of a 65-year-old male patient with FDCS of the tonsil to illustrate the radiologic findings of FDCS and also highlight this infrequent but salient differential diagnosis for adult head and neck neoplasia.

Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma presenting as a solitary colonic mass: two rare cases and a literature review

AIMS

Follicular dendritic cell (FDC) sarcoma is a rare neoplasm originating from follicular dendritic cells in germinal centres. It is classified as conventional and Epstein-Barr virus (EBV)-positive inflammatory FDC sarcoma according to the 2019 World Health Organization classification of digestive system tumours; the latter is rarer. So in view of the rarity and difficulty in diagnosis, the aim of the manuscript is to share our experience of diagnosing EBV-positive inflammatory FDC sarcoma.

METHODS AND RESULTS

Here, we describe the clinicopathological features, gross description, histomorphology, immunophenotype, EBV-encoded mRNA (EBER) in-situ hybridisation, gene rearrangement and clinical follow-up of two patients with EBV-positive inflammatory FDC sarcoma in the colon, and review the relevant literature. The tumours were found in two males, aged 53 and 48 years, respectively, with a tumour diameter between 10 and 45 mm. Both cases occurred in the colon and presented as pedunculated colonic masses. Microscopically, scanty atypical ovoid to spindle neoplastic cells were mixed in a background of florid lymphoplasmacytic infiltration. The nuclei of these atypical cells showed vesicular chromatin and small, distinct nucleoli. Immunohistochemistry demonstrated that the atypical stromal cells were positive for CD21, CD23, CD35, and D2-40. EBER in-situ hybridisation also gave positive results in two cases. There was a mean follow-up of 9 months (range, 7-11 months).

CONCLUSION

EBV-positive inflammatory FDC sarcoma is an extremely rare tumour with a distinct morphology and phenotype. Therefore, it is very important to recognise it particularly for correct diagnosis and prevention of misdiagnosis and mistreatment.

[Clinicopathological Features of Follicular Dendritic Cell Sarcoma]

Objective To explore the clinicopathological and immunohistochemical characteristics of follicular dendritic cell sarcoma(FDCS)and the expressions of IgG and IgG4. Methods We retrospectively analyzed the clinicopathological and immunohistochemical data of 9 pathologically confirmed FDCS cases in Peking Union Medical College Hospital from January 2005 to December 2018.Immunohistochemical staining of IgG and IgG4 were performed,and Epstein-Barr virus(EBV)-encoded RNA(EBER)in situ hybridization were carried out. Results Nine cases of FDCS included 4 men and 5 women aged 16-53 years [mean(38.2±9.7)years].The clinical manifestations included masses,lymph node enlargement,rash,and fever.The tumors were located in lymph node,retroperitoneal region,adrenal gland,neck,axillary region,and liver,respectively.Ultrasound showed clear boundary cystic or solid mass with maximum diameters of 1.5-15.0 cm.Microscopically,the spindle tumor cells were arranged in solid and storiform patterns with abundant and slightly stained cytoplasm,vacuolated nuclei,and small nucleoli.The mitosis was 1-3/10 high power fields,and necrosis was found in 5 cases.Immunohistochemically,the tumor cells were positive for CD21(6/9),CD35(6/9),and CD23(7/9). Conclusions FDCS is a rare malignant tumor,which is easy to be missed.The combination of CD21,CD35,and CD23 is helpful for diagnosis.Hyaline-vascular type Castleman's disease may be the precursor of FDCS,and there may be only a small number of IgG4-positive plasma cells in FDCS.Surgical resection remains the main treatment for FDCS.

Follicular dendritic cell sarcoma in the right chest wall: A case report

RATIONALE

Follicular dendritic cell sarcoma (FDCS) is a rare malignant tumor that originates from germinal center follicular dendritic cells, and can occur at both nodal and extranodal sites. There are very few described cases of FDCS arising in the chest wall.

PATIENT CONCERNS

A 44-year-old male patient presented with a history of right chest wall pain for 5 months.

DIAGNOSES

Positron emission tomography/computed tomography showed a significant increase in F-fluorodeoxyglucose uptake and multiple small axillary lymph nodes without hypermetabolic lesions. Immunohistochemistry results of a core-needle biopsy indicated FDCS, which was consistent with the postoperative pathological examination.

INTERVENTIONS

The patient underwent tumor resection with lymphadenectomy of level I axillary nodes. No metastasis in the lymph nodes was observed in the postoperative pathological examination. The patient did not accept chemotherapy or radiotherapy.

OUTCOMES

After 18 months, the patient remains in good condition with no evidence of disease recurrence.

LESSONS

This report highlights a rare case of a FDCS arising in the chest wall. Accurate clinical diagnosis and staging of this rare malignant sarcoma is essential for the developmnt of effective treatment strategies. Preoperative F-fluorodeoxyglucose positron emission tomography/computed tomography scanning combined with core-needle biopsy could provide differentiation between benign and malignant tumors, as well as lymph node involvement and metastatic status.

Fine needle aspiration of an intranodal follicular dendritic cell sarcoma: A case report with molecular analysis and review of the literature

Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm of follicular dendritic cell origin which can present a diagnostic challenge. Due to the rarity of this neoplasm, its molecular pathogenesis has not been fully elaborated. A previous series of 13 cases reported that 38% contained mutations of genes encoding proteins involved in negative regulation of NF-κB. NF-κB is a family of transcription factors regulated through multiple cellular processes known as the canonical and noncanonical pathways. Here we present the case of a 62-year-old man who presented with abdominal pain and systemic symptoms and was found to have a mass in the porta hepatis. Fine needle aspiration cytology demonstrated a spindle cell neoplasm with vesicular chromatin and prominent nucleoli with admixed lymphocytes. Surgical resection showed an intranodal, 7.3 × 5.5 × 3.5 cm, solid mass composed of plump, spindle to histiocytoid cells with ovoid nuclei and small, prominent nucleoli arranged in a whorled and fascicular pattern. The lesional cells stained positively for CD21, CD23, and CD35 by immunohistochemistry, consistent with a diagnosis of FDCS. Next-generation sequencing revealed pathologic mutations in three genes involved in NF-κB regulation pathways: NFKBIA, TNFAIP3, and TRAF3. A pathologic TP53 mutation was also identified. This case report supports prior associations of the NF-κB pathway dysregulation and FDCS. Additionally, it is the first reported FDCS case with TRAF3 mutation as well as the first reported case to suggest disruption in both the canonical and noncanonical NF-κB pathways in the same lesion.

Multiple recurrent follicular dendritic cell sarcoma: A case report

Tumors of the follicular dendritic cells (FDC-Sarcoma) represent a rare entity with only about 200 cases reported worldwide. The majority (60%) of cases arise primarily in cervical, abdominal or axillar lymph nodes, but extra nodal origin from secondary lymphatic tissue like the tonsils, Waldeyer's ring or MALT is also common (40%). The current report presents a characteristic course of a cervical FDC-Sarcoma, with its challenges in establishing the initial diagnosis and the struggle for therapeutic options. The FDC-Sarcoma presented recurrently for four times. Three different university hospitals in Germany were involved in the patients' treatment. Due to the patients' refusal, no adjuvant therapy was applied. In the end, a neck dissection was performed. The patient was closely followed up and has been recurrence-free for 10 years. This case suggests operative resection in combination with a neck dissection as a curative therapy for FDC-Sarcoma of the head and neck.

Inflammatory pseudotumor-like follicular dendritic cell sarcoma: a rare presentation of a hepatic mass

Follicular dendritic cell (FDC) sarcoma is a rare, low-grade malignant tumor originating from follicular dendritic cells in germinal centers that accounts for 0.4% of all soft tissue sarcomas. FDC sarcoma is classified into two types, the classic FDC sarcoma and inflammatory pseudotumor (IPT)-like follicular dendritic cell (FDC) sarcoma, the latter of which is rarer. IPT-like FDC sarcoma mainly involves the spleen and liver with non-specific clinical and imaging manifestations. It is often misdiagnosed as an inflammatory disease such as a liver abscess or a malignant tumor such as hepatocellular carcinoma, with a pathological morphology similar to inflammatory pseudotumors. IPT-like FDC sarcoma mainly consists of a large number of inflammatory and round, oval and spindle cells with less pleomorphism. These tumor cells are arranged in a whorled, storiform, or sheet pattern. The immunophenotype of IPT-like FDC sarcoma is the same as that of FDC sarcoma and is positive for CD21, CD23, and CD35, and positive for EBER in situ hybridization (ISH). This disease is easily misdiagnosed because it is so rare that clinicians and pathologists may not consider it in diagnosis. Here, a case of IPT-like FDC sarcoma in the liver was reported, and the related literature was reviewed to summarize the clinicopathological features, treatment, and prognosis of this rare new type of FDC sarcoma, providing new knowledge of this rare neoplasm.

Follicular Dendritic Cell Sarcoma or Not? A Series of 5 Diagnostically Challenging Cases

Imperfect or unusual presentation, morphology, or immunophenotype can make the diagnosis of follicular dendritic cell sarcoma (FDCS) very challenging. To illustrate this, we present 5 unique cases from the archives of our tertiary care academic medical center that presented a diagnostic challenge wherein FDCS was the top differential diagnostic possibility. The workup of these cases, including multiple expert consultations, highlights the importance of avoiding specific pitfalls in the diagnosis of FDCS.

Fine-Needle Aspiration Cytology of Follicular Dendritic Cell Sarcoma of Cervical Lymph Node: A Challenging Diagnosis

Follicular dendritic cell sarcoma (FDCS) is a rare malignant tumor that could arise in both nodal and extranodal sites, with only nine previously reported cases demonstrating cytologic features. In this report, we describe a case of FDCS in a 60-year-old female who presented with neck mass. Fine-needle aspiration cytology and subsequent core biopsy were suggestive of metastatic carcinoma. The cytologic features were epithelioid-to-spindle cell morphology, vesicular nuclei, prominent nucleoli, intranuclear inclusions, and occasional binucleated and multinucleated forms. However, absence of cytokeratin expression was against the diagnosis of metastatic carcinoma. The definitive diagnosis was reached by the demonstration of CD21 and CD23 expression. The pathologist should be aware of this rare malignant tumor, especially its cytologic features in aspirated material. The differential diagnosis in the above case was metastatic carcinoma, melanoma, and malignant granular cell tumor. The demonstration of expression of one or more dendritic cell marker is the clue for the diagnosis, which could be applied on cytological preparations with sufficient material.

Profiles of genomic alterations in primary esophageal follicular dendritic cell sarcoma: A case report

RATIONALE

Follicular dendritic cell (FDC) sarcoma is a rare tumor with FDC differentiation that typically arises within lymph nodes but can also occur extranodally. To date, the primary esophageal FDC sarcoma has not been reported in the English literature.

PATIENT CONCERNS

We described a 67-year-old female who foremostly presented with dysphagia, and the patient was readmitted due to a dry cough and pain of his right shoulder 2 years after initial treatment.

DIAGNOSES

Primary esophageal FDC sarcoma with the right superior mediastinal lymph node metastasis.

INTERVENTIONS

The esophageal tumor was removed by endoscopic submucosal dissection at the first hospitalization. At the second hospitalization 2 years after the initial visit, the tracheal stent loaded with (125) iodine radioactive seeds was placed. The profiles of genetic variations and immunotherapeutic biomarkers were also explored by next-generation sequencing protocol from the patient's blood, esophageal primary, and mediastinal metastatic tumor samples.

OUTCOMES

The patient's symptom transitorily relieved, but she gave up further treatment and died 2 months after the tracheal stent was placed. As for the genomic alterations, we found 9 gene mutations in all the samples, including checkpoint kinase 2(CHEK2), FAT atypical cadherin 1 (FAT1), tumor protein 53 (TP53), DPYD, ERBB2 interacting protein (ERBB2IP), FBXW7, KMT2D, PPP2R1A, TSC2, whereas amplification of MYC was only in the metastatic example. The analysis of clonal evolution and phylogenetic tree showed the propagation and replay of polyclonal esophageal FDC sarcoma. At the same time, the detection of biomarkers for immunotherapy revealed microsatellite stable and mismatch repair-proficient (pMMR), which predicted a relatively poor anti-programmed death (PD-1)/programmed death ligand (PD-L1) immunotherapy outcome. On the contrary, the tumor mutational burdens were 10 mutations per 1 million bases in both the primary and metastatic tumor sample, which ranked the top 23.3% in solid tumors mutational burdens database of Geneseeq and might be a good predictor of the efficacy of anti-PD-1/PD-L1 immunotherapy.

LESSONS

To the best of our knowledge, this case report announced the first case of extranodal primary esophageal FDC sarcoma in the world, and firstly revealed its unique genetic alterations profiles, which might contribute to further in-depth study of this rare disease.

Clinicopathologic profile of extranodal follicular dendritic cell sarcoma in the mesentery of small intestine: a study of two cases with literature review

AIM

To analyze the clinicopathologic profile of the extranodal follicular dendritic cell sarcoma (FDCS) in the mesentery of small intestine.

MATERIALS AND METHODS

The clinical observations and histopathologic andimmunohistochemical features of FDCS were analyzed in the mesentery of small intestine.

RESULTS

FDCS had no characteristic clinical manifestations. Histology showed oval sarcoma cells forming fascicles of spindle cells and whorls. Sarcoma tissue was distributed pervasively and often mixed with some T lymphoid cells. Immunohistochemical markers showed the follicular dendritic sarcoma cells were positive for CD21, CD23, CD35, D2-40 and vimentin, and weakly positive for CD68, and S-100, while EMA, CD1a, desmin, AE1/AE3, CD45RO, CD3, LCA and MPO were negative.

CONCLUSION

FDCS is a rare malignant tumor in the mesentery of small intestine.I Its diagnosis depends on the histopathology and immunohistochemical staining, and its prognosis is uncertain. Surgical operation is the first choice of treatment.

High frequency of clonal IG and T-cell receptor gene rearrangements in histiocytic and dendritic cell neoplasms

The 2008 World Health Organization (WHO) diagnostic criteria of histiocytic and dendritic cell neoplasms from hematopoietic and lymphoid tissues no longer required the absence of clonal B-cell/T-cell receptor gene rearrangements. It is true that the clonal B-cell/T-cell receptor gene rearrangements have been identified in rare cases of histiocytic and dendritic cell neoplasms, such as those with or following lymphoma/leukemia or in some sporadic histiocytic/dendritic cell sarcomas, but the clonal features of such group of tumor are still not clear. Here we investigated the clonal status of 33 samples including Langerhans cell histiocytosis (LCH), Langerhans cell sarcoma (LCS), follicular dendritic cell sarcoma (FDCS), interdigitating dendritic cell sarcoma (IDCS) and histiocytic sarcoma (HS). Among them, twenty-eight cases were sporadic without current or past lymphoma/leukemia. Three cases were found with a past history of T-cell lymphoma, one case was followed by extraosseous plasmacytoma, and one case was found with diffuse large B-cell lymphoma (DLBCL). Our results showed that there was a high frequency of clonal IG and T-cell receptor gene rearrangements in these cases. Notably, 4 cases of LCH and 2 cases of FDCS showed both B and T cell receptor gene rearrangements concurrently. One case of FDCS synchronous with DLBCL showed identical clonal IGH in both tumor populations and clonal TCRβ in FDCS alone. No matter if the presence of clonal receptor gene rearrangements was associated with the tumor origin or tumorigenesis, it might serve as a novel tumor marker for developing target therapy.

Hemorrhagic intracranial follicular dendritic cell sarcoma: A case report

Background:

Follicular dendritic cell (FDC) sarcoma is an extremely rare neoplasm, which has only been reported once in the literature with an intracranial occurrence. Neither hemorrhagic presentation of an intracranial instance of FDC sarcoma nor its rapid recurrence has yet been published in the literature.

Case Description:

We report the case of a 61-year-old female who presented with confusion and headaches secondary to a right frontal hemorrhagic lesion, and her subsequent presentations for recurrence of the lesion and finding of a new intracranial lesion. Immunohistopathologic analysis confirmed the diagnosis based on immunoreactivity for clusterin and CD 35.

Conclusion:

As demonstrated in this case report, the presentation and progression of primary intracranial follicular dendritic cell sarcoma can often be misleading, and consideration for this rare entity should be made in cases of hemorrhagic dural-based lesions without a primary source of malignancy.

Identification of novel follicular dendritic cell sarcoma markers, FDCSP and SRGN, by whole transcriptome sequencing

Follicular dendritic cell (FDC)-sarcoma is a rare neoplasm with morphologic and phenotypic features of FDCs. It shows an extremely heterogeneous morphology, therefore, its diagnosis relys on the phenotype of tumor cells. Aim of the present study was the identification of new specific markers for FDC-sarcoma by whole transcriptome sequencing (WTS). Candidate markers were selected based on gene expression level and biological function. Immunohistochemistry was performed on reactive tonsils, on 22 cases of FDC-sarcomas and 214 control cases including 114 carcinomas, 87 soft tissue tumors, 5 melanomas, 5 thymomas and 3 interdigitating dendritic cell sarcomas. FDC secreted protein (FDCSP) and Serglycin (SRGN) proved to be specific markers of FDC and related tumor. They showed better specificity and sensitivity values than some well known markers used in FDC sarcoma diagnosis (specificity: 98.6%, and 100%, respectively; sensitivity: 72.73% and 68.18%, respectively). In our cohorts CXCL13, CD21, CD35, FDCSP and SRGN were the best markers for FDC-sarcoma diagnosis and could discriminate 21/22 FDC sarcomas from other mesenchymal tumors by linear discriminant analysis. In summary, by WTS we identified two novel FDC markers and by the analysis of a wide cohort of cases and controls we propose an efficient marker panel for the diagnosis of this rare and enigmatic tumor.

Small intestine follicular dendritic cell sarcoma with liver metastasis: A case report

RATIONALE

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasia composed of spindle or oval cells with follicular dendritic cell differentiation, usually occurring in lymphoid tissue. In this report, we present a case of FDCS of the small intestine with liver metastasis.

PATIENT CONCERNS

A 19-year-old female presented with recent onset of left upper abdominal pain. Abdominal computed tomography scan showed a large tumor mass in the liver lateral segment with compression to the pancreas upper part, and a smaller mass in the terminal ileum, respectively. High serum levels of amylase and lipase were noted. Resection of the tumors was performed. Microscopically, both tumors consisted of ovoid to spindle-shaped nuclei cells admixed with some lymphocytes arranged in fascicles, whorls, storiform arrays. Immunohistochemistry demonstrated that the tumor cells were positive for follicular dendritic cell markers, including CD21, CD23, and CD35. Epstein-Barr virus encoding small RNA (EBER; Inform EBER probe; Ventana Medical Systems, Tucson, AZ) in situ hybridization was negative.

DIAGNOSES

According to the clinicopathological features, diagnosis of FDCS of intestinal origin was made.

INTERVENTIONS

Resection of tumors located in the liver and at the small intestine was performed. After the operation, patient received adjuvant vinblastin chemotherapy.

OUTCOMES

There was no evidence of recurrence at 8-month follow-up.

LESSONS

It was unusual for FDCS of intestinal origin with liver metastasis and expressing with high serum levels of pancreatic enzymes.

Characteristics, management, and outcomes of patients with follicular dendritic cell sarcoma

Dendritic cell sarcomas are rare tumours of antigen presenting cells. Data regarding their biology, management and outcomes are sparse. We analysed 66 patients with follicular dendritic cell sarcoma (FDCS). Six patients also had Castleman disease, 9 had another malignancy and 13 had an autoimmune disease. Fifty-four per cent of patients presented with localized disease and 46% with systemic involvement. The median progression-free (PFS) and overall survival (OS) following frontline therapy was 21 and 50 months, respectively. Survival outcomes were significantly inferior in patients with extranodal, bulky or intra-abdominal disease at presentation. Stage was not associated with survival. Management approaches were heterogeneous. Patients who underwent an upfront gross total resection (GTR) experienced better PFS and OS (both P < 0·0001). In patients who underwent a GTR, consolidative radiotherapy was associated with improved local control (P = 0·03), PFS (P = 0·04) and OS (P = 0·05). In patients with measureable disease, gemcitabine with a taxane yielded an overall response rate of 80%. The pattern of relapse was predominantly locoregional. Salvage rates after recurrence were poor. Studies are underway at our institution to define the genomic profile in FDCS and identify potential novel therapeutic targets.

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.

Paraneoplastic pemphigus associated with follicular dendritic cell sarcoma: report of a case and review of literature

Follicular dendritic cell sarcoma (FDCS) is a rare tumor associated with paraneoplastic pemphigus. It is Blame drenchs auxiliary cell tumor which is derived from the peripheral lymphoid tissues. Throughout the world, several patients of paraneoplastic pemphigus associated follicular dendritic cell sarcoma were reported in the literature, but mostly originated from the neck lymph nodes, and extranodal origin of follicular dendritic sarcoma was rarely reported. Also, so far we have found that the malignant degree of all patients diagnosed with malignant tumors have been reported were low and after combined treatment of surgery, radiotherapy and chemotherapy, most of the prognosis was good. However, here we present a patient of paraneoplastic pemphigus associated with follicular dendritic cell sarcoma origined from outside of the lymph nodes and had high tumor malignant degree for its unclear cell boundaries, obvious atypia and mitoses and the patient's state became progressively deteriorate after operation.

Follicular dendritic cell sarcoma with extensive lymph node involvement: A case report

Follicular dendritic cell sarcoma (FDCS) is an extremely rare neoplasm originating from the follicular dendritic cells in the lymphoid follicles. Current knowledge on its pathogenesis is limited and a well-defined treatment is required. The main channel through which clinicians obtain practical information on FDCS is via studying published case reports. To enrich the existing available literature and enhance the understanding of this rare disease, the present study describes a case of FDCS with extensive lymph node involvement in a 65-year-old male patient whose predominant symptom was a recurrent fever. The diagnosis of FDCS was eventually established based on the immunohistochemical staining of biopsy specimens of the cervical lymph nodes. The patient improved and symptoms disappeared after one cycle of systemic chemotherapy.

Follicular dendritic cell sarcoma of the right tonsil: A case report and literature review

The current study presents a case of extranodal follicular dendritic cell sarcoma (FDCS) of the tonsil and reviews the relevant literature. In the present case, a 59-year-old male presented with a globus sensation in the right pharynx for 6 weeks. On clinical examination, a painless non-ulcerated enlarged right tonsil was identified; the tonsil was covered with a normal mucus membrane. A right tonsillectomy was performed under general anesthesia. The final pathological diagnosis was follicular dendritic cell sarcoma of the right tonsil. Postoperatively, the patient received radiotherapy. The patient remains alive without disease recurrence or metastasis 44 months after tonsillectomy. To the best of our knowledge, only 42 cases of FDCS of the tonsil have been reported to date. Of the 42 cases, 41 patients underwent surgery and one patient refused treatment. A total of 23 (54.7%) received surgery alone. Adjuvant treatment was administered for 18 patients (42.9%). Six patients (14.3%) experienced local recurrences and two patients (4.8%) succumbed to the disease 24 months after treatment. The three-, five-, and eight-year overall survival rates for the entire group were 86.5, 77.8 and 77.8%, respectively. Furthermore, a tumor diameter of ≥4 cm was prognostic upon univariate analysis (χ²=4.634; P=0.031; excluding incomplete data). Tonsillar FDCS is rare and is associated with high rates of recurrence and metastasis, therefore, adjuvant treatment should be prescribed.

Extranodal follicular dendritic cell sarcoma: A clinicopathological report of four cases and a literature review

The aim of the present study was to characterize the clinicopathological features of follicular dendritic cell sarcoma (FDCS), and to report the experience of the Xin Hua Hospital Affiliated to Shanghai Jiaotong University School of Medicine (Shanghai, China) with this entity. The clinicopathological findings of four cases that had recently been encountered and 142 previously reported cases in the English literature were evaluated. The current tumors were found in two male and two female patients, aged 49–76 years old, who exhibited a mean tumor size of 8.7 cm. Three of the four cases were misdiagnosed during the initial diagnosis and one experienced intra-abdominal recurrence six months after the first diagnosis. Assessment of all 142 cases in the literature revealed a mild female predominance. The tumors exhibited a mean tumor size of ~7.0 cm. Histologically, the tumors were composed of plump spindle- or oval-shaped cells that exhibited eosinophilic cytoplasm and were arranged in sheets, storiform patterns or whorls. Immunohistochemically, the neoplastic cells expressed at least one of the FDC markers. Among the 130 cases with follow-up data, the overall recurrence, metastasis and mortality rates were 49.2% (64 cases), 21.5% (28 cases), and 13.8% (18 cases), respectively. FDCS can appear deceptively similar to other soft-tissue tumors, even poorly-differentiated carcinomas. A correct diagnosis requires a high degree of suspicion and immunohistochemical evaluation.

Follicular dendritic cell sarcoma of parapharyngeal space: a case report and review of the literature

Follicular dendritic cell sarcoma (FDCS) of the parapharyngeal space is a rare malignant tumor. Only eleven cases of FDCS of the parapharyngeal space have been reported in English literature. Most of the reported cases developed tumor recurrence within 1 year or had metastasis. Because of the rarity of FDCS in the parapharyngeal space and peculiar histology, it can be misdiagnosed as undifferentiated carcinoma or meningioma. Therefore, pathologists should be aware of the existence of FDCS in this location. This paper aims to report a unique case of FDCS of the parapharyngeal space without recurrence in 26 months follow up with a review of the literature.

Follicular dendritic cell sarcoma with paraneoplatic pemphigus: Rare case and a brief review of literature

Paraneoplastic pemphigus (PNP) is often a fatal autoimmune bullous disease characterized by severe stomatitis, polymorphous skin eruptions, and underlying neoplasms. We describe a patient with PNP associated with follicular dendritic cell sarcoma (FDCS), a rare neoplasm originating from follicular dendritic cells, which are non-lymphoid, non-phagocytic accessory cells of the lymphoid system and play an integral role in regulation of the germinal center reaction and present antigens to B-cells. The presence of rich vascularity around the tumor and few hyalanized vascular follicles found in histopathological examination gives the clue that the tumor might have developed from Castleman's disease (CD). As for the mechanisms by which CD induces PNP, it has been proposed that autoantibodies secreted from the Castleman's tumor play pivotal role. This hypothesis seems to be supported by the present case, in which CD may have triggered both the FDCS and the PNP.

Follicular dendritic cell sarcoma of the pharyngeal region

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm arising most commonly from follicular dendritic cells in the lymph nodes. It is exceedingly rare in extranodal sites, particularly in the pharyngeal region. The present study reports 3 cases occurring in the pharyngeal region. Case 1 had tonsil and cervical lymph node involvement, while case 3 also had tonsil involvement. Cases 1 and 3 relapsed locally at 3 and 17 months after surgery, respectively. Case 2 was diagnosed with a tumor in the parapharyngeal space and the patient succumbed to the disease 5 months after treatment with combined surgery and chemotherapy. All 3 cases were misdiagnosed initially. Pathological biopsy examination, including histopathology and immunohistochemistry, was essential for diagnosis. The data for 52 cases, including cases from the literature and the present cases, were analyzed. The results indicated that 57% (26/46) of the initial diagnoses were inaccurate, while the recurrence, metastasis and mortality rates were 40, 16 and 10%, respectively. The statistics supported the theory that FDCS of the pharyngeal region is a low-grade sarcoma. Involvement of the tonsils (52%, 27/52) and parapharyngeal space (19%, 10/52) were observed most commonly, while FDCS at various sites showed different prognoses. The various survival rates were calculated in the present study. The large tumors (≥4 cm) had a poorer prognosis than the small tumors (<4 cm; P<0.05). Among the 50 cases with available follow-up data, 46% (23/50) were treated with surgery alone, 52% (26/50) with combination therapy (surgery followed by chemotherapy and/or radiotherapy) and 2% (1/50) with surveillance. There was no statistically significant evidence (P>0.05) that combination therapy improves survival rates, compared with surgery alone.