Extranodal follicular dendritic cell sarcoma of the head and neck region: three new cases, with a review of the literature

Uncommon Fibroinflammatory Sinonasal Tract Lesions: Granulomatosis with Polyangiitis, Eosinophilic Angiocentric Fibrosis, and Rosai-Dorfman Disease

Fibroinflammatory lesions of the sinonasal tract include inflammatory polyps (chronic rhinosinusitis), various infectious, sarcoidosis, and NK/T-cell lymphoma as examples of the most commonly encountered lesions. However, the differential diagnosis includes several less frequently encountered entities, such as granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis (Churg-Strauss), eosinophilic angiocentric fibrosis considered part of IgG4-related disease, and Rosai-Dorfman disease. This review focuses on these latter entities providing an update on clinical, laboratory, imaging, histology, and ancillary testing employed to reach an actionable diagnosis.

Nasopharyngeal Follicular Dendritic Cell Sarcoma: Diagnostic Challenges and Therapeutic Management

Follicular dendritic cell sarcoma (FDCS) is an extremely rare malignancy arising from follicular dendritic cells accounting for less than 0.4% of all soft tissue sarcomas. While it can manifest in various anatomical locations, its occurrence in the nasopharynx is particularly uncommon with only 10 reported cases in the English literature. This case report describes a 45-year-old woman who complained of persistent neck swelling, nasal obstruction, and left ear fullness. Imaging showed a nasopharyngeal process and cervical lymphadenopathy. Biopsies confirmed FDCS. Treatment included chemotherapy and radiation, resulting in a favorable outcome with no recurrence during 2 years of follow-up.

Follicular Dendritic Cell Sarcoma of the Parotid Gland: A Case Report and Review of Literature

Follicular dendritic cell sarcoma of the parotid gland is an extremely rare tumor, with only six cases reported in the literature. A 51-year-old female had a 3.0 cm tumor resected from the right parotid gland. The tumor exhibited solid sheets, whorls, fascicular pattern, and syncytium appearance with an indistinct cell border. The lymphocytic infiltrate was sprinkled throughout the neoplasm, with focal prominent perivascular cuffing. Immunohistochemically, it was positive for follicular dendritic cell markers CD21, CD23, and CD35. We aim to enhance the understanding of this neoplasm and alert pathologists to this rare entity in this region to avoid misdiagnosis.

EBER-negative inflammatory pseudotumor-like follicular dendritic cell sarcoma of liver: A case report

RATIONALE

Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) of the liver is rare. It was previously believed that Epstein-Barr virus (EBV) positivity was a necessary criterion for pathological diagnosis. However, we found that there were also cases of EBV negativity. Therefore, clinicians and pathologists are reminded that EBV positivity is not a necessary condition for diagnosis.

PATIENT CONCERNS

A 70-year-old female underwent computed tomography (CT) examination for upper abdominal discomfort, which revealed the presence of a liver tumor. Follow-up revealed that the tumor had progressively increased in size.

DIAGNOSIS

The final diagnosis was an IPT-like follicular cell sarcoma, based on CT, MRI, HE staining, and immunohistochemical staining.

INTERVENTIONS

The patient underwent a laparoscopic left hemihepatectomy.

OUTCOMES

The patient has not undergone any special treatment, such as radiotherapy and chemotherapy, and has been followed up for over 3 years without experiencing any recurrence.

LESSONS

IPT-like FDCS is a rare tumor that lacks definitive criteria, and its diagnosis mainly relies on pathological findings. Previously, it was believed that being EBV-positive was an important condition for diagnosis. Primary IPT-like FDCS in the liver is even rarer, and the patient in this case tested negative for EBV. It may be necessary for pathologists to consider the role of EBV in the diagnosis of IPT-like FDCS.

Primary follicular dendritic cell sarcoma of the kidney - a case report of a rare tumor with emphasis on diagnostic pitfalls

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare low-grade tumor of the lymph nodes, but roughly one-third of the cases emerge from extranodal sites, posing diagnostic challenges.

CASE PRESENTATION

In this report, we present the case of a 59-year-old lady who complained of renal colic. During investigation, a kidney tumor was discovered. A radical nephrectomy was performed, and histological examination identified the tumor as a sarcomatoid renal cell carcinoma. The case was then referred to a genitourinary pathologist for further evaluation. The tumor cells exhibited positive staining for CD21, CD23, somatostatin receptor 2 A, and MDM2 expression. Additionally, MDM2 gene amplification was confirmed by the FISH study. Ultimately, the tumor was diagnosed as a primary renal FDCS. The patient was placed under active oncological surveillance and did not receive any further therapy. Remarkably, after 91 months of follow-up, she remains tumor-free.

CONCLUSION

This case represents a well-documented primary renal FDCS. Our aim in presenting this extremely rare tumor is to enhance awareness and highlight the importance of considering FDCS in the differential 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.

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.

Top Ten Lymphoproliferative Lesions Not to Miss When Evaluating Oral Ulcer Biopsies

BACKGROUND

Oral ulcers represent a full thickness loss of the mucosal epithelium leading to exposure of the submucosal connective tissue. These are common and usually self-limited lesions, although they may sometimes result from neoplasms, most commonly squamous cell carcinoma. Lymphoproliferative disorders may be difficult to diagnose in apthous ulcers since they mimic reactive inflammation.

METHODS

This review presents ten rare oral lymphoid proliferations which should not be missed when assessing oral ulcer biopsies.

RESULTS

The ten lesions include several with diagnostic cells which look similar to the histiocytes of a reactive inflammatory ulcer, including Rosai-Dorfman disease, reticulohistiocytoma, Langerhans cell histiocytosis, and traumatic ulcerative granuloma. Other lesions, such as EBV-positive mucocutaneous ulcer, extranodal marginal zone lymphoma of mucosal-associated lymphoid tissue, and plasmablastic lymphoma have lymphoid and/or plasma cell differentiation that mimic the reactive lymphocytes and plasma cells found in reactive ulcers. Two dendritic cell lesions, follicular dendritic cell sarcoma and blastic plasmacytoid dendritic cell neoplasm, both have distinct phenotypes which are required to make an accurate diagnosis.

CONCLUSION

Each of these lesions are diagnosed by evaluating their histology, along with their phenotypic profile, which is sometimes enhanced by pertinent molecular findings.

Imaging and pathological comparison of inflammatory pseudotumor-like follicular dendritic cell sarcoma of the spleen: A case report and literature review

Background

Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) is a rare subtype of follicular dendritic cell sarcoma (FDCS) that is mainly located in the liver and spleen (1). Splenic IPT-like FDCS is a rare low-grade malignancy with non-specific clinical manifestations and laboratory findings. Herein, we reported the pathological and imaging features of a case with splenic IPT-like FDCS.

Case presentation

A 57-year-old woman was found to have a mass in the spleen during a physical examination and was hospitalized for further treatment. Her laboratory results were within the normal range. Unenhanced and contrast-enhanced computed tomography scans of the whole abdomen showed a round mass in the spleen, with a diameter of about 5 cm. After further examination with enhanced MRI, a provisional diagnosis of splenic hemangioma or splenic hamartoma was made. The patient underwent splenectomy, and the pathological diagnosis was splenic IPT-like FDCS. No tumor recurrence or metastasis was found during the 1-year follow-up after the operation.

Conclusions

Herein, we reported a case of splenic IPT-like FDCS. Although the clinical examination and laboratory examination lack specificity, the imaging of this case showed that the lesion was a solid mass with progressive enhancement, and the central scar showed the characteristics of delayed enhancement, which facilitated the diagnosis.

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.

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.

Extranodal Follicular Dendritic Cell Sarcoma-A Review: "What the Mind Does Not Know the Eye Does Not See"

Follicular dendritic cell sarcoma (FDCS) is an intermediate-grade malignancy of follicular dendritic cells, which are derived from mesenchymal stem cells. Nodal FDCS is well-recognized. However, when it occurs at an extranodal site, it may not be recognized and is often misdiagnosed. These tumors exhibit a variable spindle to epithelioid cell morphology with a lymphocytic infiltrate and a distinct immunophenotype. The World Health Organization has classified this entity under tumors of hematopoietic and lymphoid tissue, that is, histiocytic and dendritic cell neoplasms. However, its occurrence at extranodal sites and its behavior and management more closely resemble that of a soft tissue tumor. Increased awareness about the existence of FDCS at extranodal sites may aid in the reduction of diagnostic errors. We wish to draw attention to this entity by reporting our experience of 54 cases of extranodal FDCS encountered over a period of 14 years and present a review of the literature of this underrecognized entity. We also describe the ontogeny and molecular pathogenesis of this uncommon lesion.

Intra-abdominal Follicular Dendritic Cell Sarcoma (FDCS): Series of 18 cases of a rare entity from Pakistan

OBJECTIVES

Follicular Dendritic Cell Sarcoma (FDCS) is a rare neoplastic proliferation of dendritic cells which are immune accessory cells found in both lymphoid and non-lymphoid organs. FDCS can thus occur in lymph nodes as well as non-lymphoid organs. Intraabdominal FDCS is even rarer. Our aim was to describe the clinical and morphological features of intra-abdominal FDCSs diagnosed in our practice and to review published literature on FDCSs including intra-abdominal FDCSs.

METHODS

All cases of FDCSs diagnosed between January 1, 2008 and December 31, 2019 were included in the study. Slides of the cases were reviewed and clinical follow up was obtained.

RESULTS

A total of 18 cases of intraabdominal FDCS were diagnosed during the study period. Age range was 17 to 55 years. Mean and median ages were 28 and 29 years respectively. Of the 18 patients, 11 were male and 7 were females. Colon was involved in 9 cases and appendix in 2 cases. 9 cases were received as resection specimens while 9 cases were received as slides and blocks for second opinion. Tumor size ranged from 2.7 to 26 cm. Average tumor size in these 9 cases was 8.2 cm and in 6 of these 9 cases, tumor size was greater than 6 cm in largest dimension. Grossly, tumors were nodular or polypoid and had a fleshy, grey white, homogeneous cut surface. Histologically, all 18 cases showed proliferation of plump to spindle shaped cells arranged in a fascicular or storiform pattern. Tumor cells had mild to moderately pleomorphic spindle to ovoid vesicular nuclei with fine chromatin and inconspicuous to variably conspicuous nucleoli, and moderate amount of pale eosinophilic cytoplasm. Mitotic activity was usually brisk. CD21 and CD23 were positive in all 18 cases. Resection margins were negative in all 9 resection specimens. Lymph nodes positive for metastases were seen in 4 cases. Follow up was available in 13 cases. Recurrence was seen in 6 patients, out of which 3 patients died of disease 15, 17- and 24-months following resection. 1 patient with appendiceal FDCS was free of disease almost 12 years after surgery but recently developed recurrence and is currently undergoing chemotherapy. 6 patients were alive and well at the time of follow-up 5 to 68 months after resection. None of them had developed recurrence or metastases at the time of follow up. 8 of the 13 patients received chemotherapy and/or radiotherapy post-surgical resection.

CONCLUSION

Colon was involved in 9 of our 18 cases. Lymph nodes were positive for metastases in 4 out of 9 resection specimens. All cases were diagnosed based on morphology supported by positivity for immunohistochemical stains CD21 and CD23. Histological factors associated with aggressive behavior were seen in 14 cases. Majority of patients had an aggressive clinical course.

Follicular dendritic cell sarcoma presenting as a thyroid mass: an unusual case report and literature review

Thyroid follicular dendritic cell sarcoma (FDCS) is an extremely rare malignancy that originates from follicular dendritic cells of the germinal centers and is characterized by the neoplastic proliferation of spindled to ovoid cells. As there have been only five cases reported in the literature until now, the diagnostic and therapeutic information available to clinicians regarding thyroid FDCS is fairly limited. To our knowledge, this is the first case report of thyroid FDCS without a history of Hashimoto’s thyroiditis. A 48-year-old woman was found to have a slow-growing mass in the left thyroid. After total thyroidectomy and left modified radical neck dissection, the specimen demonstrated morphologic and immunohistochemical features of FDCS. The patient had a favorable prognosis with no evidence of disease 11 months after tumor excision.

Fine-Needle Cytological Characteristics of Carcinoma Breast with Medullary or Medullary-like Features Masquerading as Dendritic Reticulum Cell Sarcoma: An Attempt to Explore the Reasons for Erroneous Cytologic Interpretation

Background:

Infiltration of tumors by dendritic reticulum cells (DRC) reflects the host immune defense mechanism. We observed three breast carcinomas cases with dense tumor-infiltrating DRC and lymphocytes in fine-needle aspiration (FNA) smears, leading to cytodiagnosis or differential diagnosis of dendritic reticulum cell sarcoma (DRCS). An attempt was made to find out the reason behind such an erroneous interpretation.

Materials and Methods:

Between 2009 and 2014, two cases were diagnosed as DRCS of the female breast by FNA cytology and in one case possibility of DRCS was considered along with medullary breast carcinoma (MBC). We compare and contrast the cytomorphological features of these three cases with those of nine cytologically diagnosed MBC.

Results:

Cases diagnosed as DRCS or MBC showed singly dispersed tumor cells, nuclear pleomorphism, bare nuclei, prominent nucleoli, and presence of lymphocytes. There was no significant difference between the two groups for discohesive clusters, syncytial clusters, plasma cells, neutrophils, foamy histiocytes, and necrosis. However, there was significant difference for presence of cohesive clusters (0% DRCS and 100% MBC, P = 0.00485), severe degree (+++) of pleomorphism (100% DRCS vs. 11.1% MBC, P = 0.01818), +++ DRC (P = 0.04697), and DRC with ++ to +++ enlarged nuclei (P = 0.03333), and pleomorphic nuclei (P = 0.00833). Two of the three cytologically diagnosed DRCS cases proved to be MBC or MBC-like and one as invasive ductal carcinoma. Six of nine cytologically diagnosed MBC cases with histology proved to be invasive breast carcinomas.

Conclusion:

Criteria for cytodiagnosis MBC need a fresh look. Cases with numerous dendritic cells possibly represent MBC.

Tonsillar p16-Positive Follicular Dendritic Cell Sarcoma Mimicking HPV-Related Oropharyngeal Squamous Cell Carcinoma: A Case Report and Review of Reported Cases

Follicular dendritic cell sarcoma (FDCS) is a rare entity which can share morphologic features with non-keratinizing squamous cell carcinoma. Recent reports suggest that up to half of FDCSs show immunohistochemical positivity for p16 (Zhang et al., in Hum Pathol 66:40-47, 2017), a stain that is conventionally used in the risk stratification of oropharyngeal squamous cell carcinoma (OPSCC). Herein, we report a case of p16-positive FDCS with clinical and histomorphologic overlap with human papilloma virus (HPV)-related OPSCC.

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.

Temozolomide targets and arrests a doxorubicin-resistant follicular dendritic-cell sarcoma patient-derived orthotopic xenograft mouse model

Follicular dendritic cell sarcoma (FDCS) is a very rare and highly recalcitrant disease. A patient's doxorubicin-resistant FDCS was previously established orthotopically on the right high thigh into the biceps femoris of mice to establish a patient-derived orthotopic xenograft (PDOX) model. The aim of the present manuscript was to identify an effective drug for this recalcitrant tumor. Here, we evaluated the efficacy of temozolomide (TMZ), trabectedin (TRAB) and pazopanib (PAZ) on the FDCS PDOX model. PDOX mouse models were randomized into five groups of eight to nine mice, respectively. Group 1, untreated control with PBS, i.p.; Group 2, treated with doxorubicin (DOX), 2.4 mg/kg, i.p., weekly for 3 weeks; Group 3, treated with PAZ, 50 mg/kg, oral gavage, daily for 3 weeks; Group 4, treated with TMZ, 25 mg/kg, oral gavage, daily for 3 weeks; Group 5, treated with TRAB, 0.15 mg/kg, i.v., weekly for 3 weeks. Body weight and tumor volume were assessed 2 times per week. TMZ arrested the FDCS PDOX model compared to the control group (p < 0.05). PAZ and TRAB did not have significant efficacy compared to the control group (p = 0.99, p = 0.69 respectively). The PDOX tumor was resistant to DOX (p= 0.99). as was the patient. The present study demonstrates that TMZ is effective for a PDOX model of FDCS established from a patient who failed DOX treatment, further demonstrating the power of PDOX to identify effective therapy including for tumors that failed first line therapy.

Primary Tonsillar Epithelioid Follicular Dendritic Cell Sarcoma: Report of a Rare Case Mimicking Undifferentiated Carcinoma and a Brief Review of the Literature

We present a 52 years old male with a left tonsillar follicular dendritic cell sarcoma with prominent epithelioid features that on light microscopical examination bore a striking resemblance to a lymphoepithelial or undifferentiated carcinoma. The tumor was immunohistochemically positive for CD21 and CD35 and negative for cytokeratins. Two distinct histopathological features (both present in our case) that may serve as clues to the correct diagnosis on light microscopical examination were formation of ectatic pseudovascular spaces lined by malignant cells and the presence of non-neoplastic multinucleated giant cells. Familiarity with the above-mentioned morphological clues, and awareness that this tumour may occur in anatomical sites outside the lymph node, are essential for accurate diagnosis.

Unusual Presentation of Follicular Dendritic Cell Sarcoma as a Cystic Neck Swelling

Follicular dendritic cell sarcoma is a very rare neoplasm that most commonly involves cervical lymph nodes and usually presents as a solid mass. Presentation as a cystic neck mass is very rare. Radiological studies and aspiration cytology are often unreliable, and diagnosis is usually made after thorough clinical and pathological examination along with immunohistochemical analysis. In this article, we report a case of a 42-year-old man who presented with right-sided neck swelling of a 2-month duration. Contrast-enhanced CT showed a cystic lesion in the right side of the neck inferomedial to parotid gland located between medial border of sternocleidomastoid muscle and internal jugular vein. Fine needle aspiration cytology was inconclusive. Patient underwent excision biopsy. Histological examination showed a solid-cystic tumor composed of spindle cells arranged in storiform pattern and showed a positive staining for CD23, CD35, and CD21 that confirmed the diagnosis of follicular dendritic cell sarcoma.

Follicular dendritic cell sarcoma presenting as a painless lump in the parotid

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm of the antigen presenting cells of the immune system. The majority occur in lymph nodes but around 30% can occur extranodally including in the spleen, lungs, head and neck and liver. We present an unusual case of an FDCS of the parotid gland in a 51-year-old woman with a history of Hodgkin's lymphoma treated with combination chemotherapy and modified mantle radiotherapy. Only four cases of an intraparotid FDCS have been previously reported. The patient underwent a superficial parotidectomy and level 2/3 neck dissection. A diagnosis of an intraparotid FDCS (25 mm) with no nodal disease was made. Given this patient's history of radiotherapy 20 years previously, we speculate the possibility of postradiation sarcoma.

Follicular dendritic cell sarcoma of the duodenum: an extremely rare entity

Extranodal follicular dendritic cell sarcoma (FDCS) is a very rare tumour, only reported in case reports and case series. It poses diagnostic and management challenge both to the clinician and pathologist. We present such a rare case of duodenal FDCS in a 56-year-old woman who was recently managed in our institution. Repeated pre surgical biopsies were non-diagnostic and the final diagnosis was made only after surgical excision of the tumour and with the help of histopathological and immunohistochemical studies. The patient had a complete en block resection of the tumour and was discharged home well 5 days postsurgery. To the best of our knowledge, this is the first case of FDCS reported arising from the duodenum.

Retroperitoneal follicular dendritic cell sarcoma in a young woman: Diagnosis and treatment challenges

INTRODUCTION

Follicular dendritic cell sarcoma (FDCS) is an uncommon tumor that usually arises in lymph nodes, especially in the cervical, mediastinal, or axillary areas, but rarely in extranodal sites. Few cases have been reported in English literature so far. The scarcity may be partially due to under-recognition of this entity. Through this case report we analyzed the difficulties of clinical and pathological diagnosis of this rare tumor with its unusual location mistaken it with gynecological cancer's iliac lymph nodes metastases. We also discussed its systemic treatment options.

CASE REPORT

A 48-year-old woman presented with a loss of weight and epigastralgia. Computed tomography (CT) showed a mass of 5cm of diameter, located close to iliac vessels. Investigation for gynecologic cancers was negative and a partial tumor resection was performed. Pathological examination readdressed the diagnosis of FDCS. Microscopically, the tumor was composed of a proliferation of spindle to ovoid cells arranged in fascicles, whorls and storiform pattern, accompanied by sprinkling of small lymphocytes. The nuclei of the tumor cells were elongated spindled or ovoid shape with vesicular chromatin and distinct small nuclei. Immunohistochemically, the tumor cells were positive for CD21, CD23 but negative for any type of cytokeratin. Even pathological diagnosis was misleading, therapeutic management was more challenging with this unusual location particularly associated with an aggressive clinical course. Two lines of chemotherapy gave different responses.

CONCLUSION

Clinical and pathological diagnosis of retroperitoneal FDCS needs vigilance. Both lymphoma and sarcoma chemotherapy regimens are effective. Due to this pathology's rareness we highlighted a lack of treatment consensus and proposed options.

Follicular dendritic cell sarcoma of the liver with metachronous small bowel and splenic metastases: a case report and literature review

Follicular dendritic cell sarcoma (FDCS) of the liver is an extremely rare disease, accounting for a mere 0.4% of all soft tissue sarcomas. FDCS most commonly involves lymph nodes but also affects extranodal sites such as the gastrointestinal system, oral cavity, liver, spleen and pancreas, albeit less commonly. It is widely considered a low-to-intermediate grade malignancy. We report a case of FDCS with metachronous involvement of the liver, small intestines and spleen, its imaging, histological findings and its management.

Follicular Dendritic Cell Sarcoma

Follicular dendritic cell sarcoma is a rare tumor that typically arises within lymph nodes but can also occur extranodally. It is important to have a high index of suspicion, so follicular dendritic cell sarcoma is included in the differential diagnosis of a spindle cell neoplasm in the appropriate clinical and morphologic settings. When included in the differential diagnosis, immunohistochemistry is generally sufficient to substantiate the diagnosis of follicular dendritic cell sarcoma. In this review, we discuss the clinicopathologic features of follicular dendritic cell sarcoma, recent molecular and cytogenetic findings, prognosis, and current approaches to treatment.

Recurrent Follicular Dendritic Cell Sarcoma of the Parotid Gland Imaged with 18F-FDG PET/CT

Follicular dendritic cell sarcoma (FDCS) is an extremely rare tumor with only 67 cases of head and neck FDCS reported in the literature. A 65-year-old female had a 6-cm follicular dendritic cell sarcoma resected from the left parotid gland with close margins. It recurred 1 year later as a 5-cm mass that was intensely [18F] fluoro-2-deoxy-D-glucose (18F-FDG) avid on positron emission tomography/computed tomography (PET/CT) and was re-excised. A follow-up PET/CT did not show any metastatic disease. The use of 18F-FDG PET/CT in the management of FDCS warrants further research. We present the 18F-FDG PET/CT imaging findings of this rare tumor.

Follicular Dendritic Cell Sarcoma of Appendix Presenting as Acute Appendicitis

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm that originates from dendritic cells of lymphoid follicles and shows low to intermediate malignant potential. It most commonly arises from lymph nodes, but may originate from a variety of extranodal sites. FDCS of appendix is exceptionally rare, and only a single case has been reported. Herein, we describe the clincopathological features of a case of FDCS originating from appendix with emphasis on being able to recognize this rare neoplasm in the context of the differential diagnosis of more common intraabdominal spindle cell tumors.

Clinicopathological Profile and Outcomes of Follicular Dendritic Cell Sarcoma of the Head and Neck Region - A Study of 10 Cases with Literature Review

INTRODUCTION

Follicular Dendritic Cell Sarcomas (FDCS) are rare disorders of the lymph node and soft tissues. Accurate characterization of these neoplasms is important in planning optimal treatment given its potential for recurrence and metastasis.

AIM

To analyse the clinicopathological profile and outcomes of a series of 10 cases of follicular dendritic cell sarcoma arising in the head and neck region diagnosed at our regional cancer centre.

MATERIALS AND METHODS

A series of 10 cases of FDCS of the head and neck region from the hospital registry of head and neck cancers diagnosed between 2007 and 2013 were collected and analysed retrospectively. Clinical details, pathologic features, immuno-phenotypic profile, treatment approach and outcomes over a period of 5 years were noted. The Recurrence Free Survivals (RFS) of all the patients were recorded.

RESULTS

The median age of the patients was 57 years and the mean age was 50.9 years. Male: female ratio was 7:3. In eight of the 10 patients, the tumours were located in the tonsils. All the tumour cells showed diffuse cytoplasmic CD21 and CD23 positivity by IHC. All the 10 cases underwent surgical excision of the tumour and three cases underwent additional neck dissection for cervical lymph node enlargement. All the patients with high grade tumours were uniformly managed with Tri-modality treatment (Surgery followed by radiotherapy and chemotherapy). The overall recurrence rate was 70%. The mean and median recurrence free survival was 39.6 and 44 months, respectively. Two of the three patients who remained recurrence free at the end of the 60 months had low grade tumours.

CONCLUSION

Early recognition of follicular dendritic cell sarcomas requires a high index of suspicion and bi-modality or tri-modality treatment may cure a subset of low and high grade tumours respectively and prolong recurrence in a large subset of patients. Surgery is the mainstay and the definitive modality of treatment; the advantages and benefit of adjuvant radiotherapy and chemotherapy are yet to be established. Tri-modality management may have a role in high grade patients which needs to be substantiated in future studies.

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

Follicular dendritic cell sarcoma (FDCS), which originates in antigen-presenting cells of the B-cell follicles of the lymph nodes, is an uncommon disease, particularly in a splenic location. In a number of cases, FDCS may easily be confused with other solid tumors and be underdiagnosed. The present study reports a case in which such as tumor occurred in a 64-year-old woman. The patient presented with an abdominal mass, and computed tomography was performed. Histological and immunohistochemical studies revealed a diagnosis of FDCS. The patient underwent surgical treatment and had a good remission. At the time of writing, the patient was in good condition. The present study also discusses the clinical characteristics, treatment methods and prognosis of FDCS, with particular reference to the main points of the imaging diagnosis.

Paraneoplastic Pemphigus Associated with Follicular Dendritic Cell Tumor in the Mediastinum

Paraneoplastic Pemphigus (PNP) is an autoimmune bullous disease characterized by severe stomatitis, polymorphous skin eruptions, and underlying neoplasms. Diagnosis of cutaneous paraneoplastic disorders requires high index of suspicion. We describe a patient with PNP associated with follicular dendritic cell (FDC) tumor in the mediastinum, a rare neoplasm originating from follicular dendritic cells. Its management requires identification of underlying malignancy and treatment of the same. Our patient showed remission of PNP upon excision of the tumor and remained disease-free for 8 years.

Clinicopathological characteristics of mediastinal follicular dendritic cell sarcoma: report of three cases

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm of follicular dendritic cells that form a tight meshwork within lymphoid follicles. It occurs most commonly in the lymph nodes and occasionally at extranodal sites, but rarely in the mediastinum. It is an under-recognized clinical entity without clear diagnosis. Due to its rarity, FDCS is easily misdiagnosed by clinicians or pathologists.

CASE PRESENTATION

Herein, we report three unusual cases of mediastinal FDCS, including one with hyaline vascular Castleman's disease in woman. The clinicopathological characteristics and CT imagings were described. Their diagnosis was confirmed by immunohistochemical stainings of specific markers. Their therapeutic intervention, follow-up and outcomes were presented with brief literature review.

CONCLUSIONS

A huge mediastinal shallowly-lobulated, demarcated soft tissue mass, with speckled, strip-like, coarse or arborizing calcification inside, and mild to moderate enhancement after contrast material administration on CT image, should consider FDCS as a possible diagnosis.

Follicular dendritic cell sarcoma of the head and neck: Case report, literature review, and pooled analysis of 97 cases

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare lymphoid neoplasm presenting in the head and neck. There are no pooled analyses of head and neck FDCS cases in the English language literature.

METHODS

A MEDLINE and PubMed review of cases from 1978 to February 2014 was performed. Demographics, clinicopathologic data, and outcomes were summarized.

RESULTS

We presented 2 patients and analyzed 97 cases. The mean age was 42.7 years (SD = 16.3 years). Outcomes were available for 76 patients. Tumors ≤4 cm had better disease-free survival (63% vs 28% at 5 years; p = .0282). Locoregional recurrence was significantly less likely with surgery and radiation compared to surgery alone (15% vs 45%; p = .019) and in patients receiving a neck dissection (10% vs 43%; p = .046).

CONCLUSION

This pooled analysis provides the largest sample size of FDCS of the head and neck to date and suggests that radiation and neck dissection may be beneficial to locoregional oncologic control. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2241-E2249, 2016.

Extranodal hematopoietic neoplasms and mimics in the head and neck: an update

The head and neck region is a common site for extranodal lymphomas, second only to the gastrointestinal tract; and 12% to 15% of all head and neck tumors are lymphomas. Non-Hodgkin lymphomas are most common, and Hodgkin lymphoma occurs rarely at extranodal sites in the head and neck. Most non-Hodgkin lymphomas of the head and neck region are of B-cell lineage, and the Waldeyer ring is the most common site. Head and neck lymphomas have distinctive epidemiological and clinicopathologic features, including an association with immunosuppression, infectious organisms, or autoimmune disorders; site-specific differences (eg, thyroid gland versus ocular adnexa) for common lymphomas, such as extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue; and genetic differences that provide insights into etiology. Furthermore, the diagnosis of non-Hodgkin lymphomas at extranodal sites implies differences in prognosis and therapeutic implications with lymphomas at nodal sites. In this review, we discuss various types of non-Hodgkin lymphomas and Hodgkin lymphoma, focusing on unique aspects related to the head and neck region. We also discuss a number of newer entities that are clinically indolent as well as mimics of lymphoma that can occur in the head and neck region, including infectious mononucleosis, Kikuchi-Fujimoto disease, Kimura disease, Castleman disease, and immunoglobulin G4-related disease.

Intraperitoneal follicular dendritic cell sarcoma: role of chemotherapy and bone marrow allotransplantation in locally advanced disease?

We describe a case of a 44 year-old woman diagnosed with follicular dendritic cell sarcoma (FDCS). FDCS is a very rare disease affecting the dendritic antigen presenting cells and is often misdiagnosed. Surgery is considered the best treatment modality, followed by chemotherapy. In our case, surgical excision was not possible, therefore the patient received two lines of chemotherapy followed by bone marrow allotransplantation, then a third line of chemotherapy with a complete metabolic response seen on PET/computed tomography (CT) follow-up 29 months later. A review of the literature has been performed.

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 the tonsil

Follicular dendritic cells (FDCs) are non-phagocytic, non-lymphoid cells of immune system, which are necessary for antigen presentation and regulation of the reactions in the germinal centers of lymph node. Follicular dendritic cell sarcoma (FDCS) is unusual and those with an extranodal origin in the head and neck region are extremely rare. Here, we report a case of FDCS of the left tonsil in a 27-year-old male patient. The patient presented with swelling of the left tonsil and resultant difficulty in swallowing for last three months. The tumor was excised and was sent for histopathologic examination. Microscopic examination and immunohistochemical analysis proved the case to be FDCS. After the diagnosis, the patient received post-operative radiotherapy. The patient is on six months follow-up which is uneventful.