Challenges in the Diagnosis of Epstein-Barr Virus-positive Inflammatory Follicular Dendritic Cell Sarcoma: Extremely Wide Morphologic Spectrum and Immunophenotype

Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma: A brief report of a rare neoplasm diagnosed with cytopathology on a splenic biopsy

Splenic biopsies for cytology remain challenging due to the inherent difficulty in obtaining adequate samples and the paucity of literature on rare entities arising in the spleen. Among these, are tumors arising from blood vessels, lymphomas and rarely, mesenchymal dendritic cell neoplasms. An important but rarely considered entity primarily arising in the spleen is Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma (EBV+ IFDCS). EBV+ IFDCS is an indolent neoplasm with useful cytomorphologic and distinct biologic characteristics that can be evaluated on fine-needle aspiration (FNA) cytology and small biopsies. In this report, we present a challenging case with the final diagnosis facilitated by cytomorphology and diagnostic markers in an ambiguous initial presentation.

Clinicopathological and molecular genetic insights into EBV-positive inflammatory follicular dendritic cell sarcoma

Epstein-Barr virus (EBV)-positive inflammatory follicular dendritic cell (FDC) sarcoma (EBV + IFDCS) is a rare entity, and its histopathological characteristics have not been fully described. This study aimed to investigate the clinical characteristics, pathological features, and molecular genetic profiles of EBV + IFDCS to improve our understanding of these lesions. A total of 12 EBV + IFDCS specimens were obtained from patients in our pathology diagnostic center. The clinical data, morphology, immunohistochemistry, in situ hybridization, and high-throughput DNA-targeted sequencing data were collected, and follow-up data were analyzed. These data were compared with those of 6 patients with traditional FDCS. The patients with EBV + IFDCS ranged from 21 to 84 years old, with a mean age of 52.3 years and a male-to-female ratio of 1:5. At the last follow-up, all patients were alive, with 2 experiencing recurrence and metastasis. In these cases, four were classified as the classical subtype, four as the angiomatoid/sclerosing subtype, and four as the lymphoma-like subtype, with two cases also exhibiting epithelioid granulomas. All patients exhibited heterogeneous expression of follicular dendritic cell markers (CD21, CD23, CD35, and CXCL13) alongside the fibroblast marker SMA, with significantly higher expressions of IgG4, EBER, and SMA in EBV + IFDCS patients compared to FDCS patients (P < 0.05). Conversely, SSTR2, EGFR, and STAT3 expression were significantly lower in the EBV + IFDCS group (P < 0.05). The average value of EBER was significantly higher in the classical subtype group (P = 0.022). Among the four cases of EBV + IFDCS analyzed for molecular genetic features, one patient exhibited germline mutations in the CDKN1C, PDGFRA, MSH2, FANCG, MLH1, ALK, and RUNX1 genes; three exhibited simultaneous SNP variations in the MTHFR gene; and two exhibited simultaneous SNP variations in the NQO1 gene. We conducted KEGG pathway analysis on the mutant genes, revealing significant enrichment in the cAMP signaling pathway, which plays a crucial role in tumor development. Survival analysis demonstrated that the median PFS rates were not reached (NR) for EBV + IFDCS patients, compared to 5 months (HR = 7.76) for FDCS patients. The 3-year PFS rates were 66.67% and 16.67%, respectively. Compared with the FDCS group, EBV + IFDCS patients had a significantly longer median PFS time (p < 0.05). In conclusion, EBV + IFDCS represents a group of tumors with unique clinical, morphological, immunological, prognostic, and molecular cytogenetic characteristics.

Epstein-barr virus (EBV)-positive inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) presenting as thrombocytopenia: A case report and literature review

Background

Follicular dendritic cell sarcoma (FDCS) represents an exceedingly rare malignant neoplasm. Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) is recognized as a variant manifestation of FDCS. The clinical incidence of this particular disease is remarkably low, resulting in the absence of established standardized clinical protocols for its management and treatment.

Methods

Presented here is a case of primary Epstein-Barr virus (EBV)-positive splenic IPT-like FDCS, noteworthy for manifesting thrombocytopenia as its initial symptom. Our study analyzed the clinicopathologic characteristics of this case and 29 previously reported cases identified in the literature. Also, we conducted a comprehensive review of pertinent literature.

Results

We administered splenectomy to this patient and verified the diagnosis of EBV-positive IPT-like FDCS through immunohistochemical examination. Postoperatively, the patient underwent a one-year follow-up period, demonstrating no signs of recurrence. Analyzing a total of 30 cases revealed that this disease is more prevalent in female patients (F:M = 1.14:1), with a median age of 62 years. Fifteen patients were asymptomatic, and nine patients presented with abdominal discomfort or pain. All patients underwent surgical treatment. Among the cases, histopathological and immunohistochemical information was unavailable for five; however, in the remaining 25 cases, histopathology revealed a distinct inflammatory cell infiltration and spindle tumor cells arranged in sheets or fascicles. These tumor cells had vesicular chromatin and distinct nucleoli and they expressed conventional FDC markers. In situ hybridization analysis of Epstein-Barr virus-encoded small RNA (EBER) showed that all 30 cases were EBV-positive. Follow-up information showed that no patients relapsed and one (3.8 %) patient died.

Conclusion

The clinical diagnosis of EBV-positive IPT-like FDCS poses considerable challenges, necessitating a conclusive diagnosis through pathological immunohistochemical examination. EBER in situ hybridization holds significance for the definitive diagnosis of the disease. We advocate for splenectomy as the treatment of choice for limited splenic IPT-like FDCS.

Stroma-derived neoplasms and pseudoneoplastic lesions of the spleen: a select review of pathologic and CT/MRI findings

A wide spectrum of benign and malignant primary mesenchymal tumors and tumor-like lesions of the spleen has been recently included under the umbrella term 'stroma-derived' neoplasms and tumor-like lesions. These include dendritic cell neoplasms such as follicular dendritic cell sarcoma, EBV-positive inflammatory follicular dendritic cell sarcoma, and fibroblastic reticular cell tumor; smooth muscle and myofibroblastic lesions such as inflammatory pseudotumor, EBV-associated smooth muscle tumor and undifferentiated pleomorphic sarcoma as well as a diverse spectrum of vascular and vascular-stromal tumors and tumor-like lesions. While some tumor and tumor-like lesions are unique to the spleen, others may also occur in diverse extra-splenic viscera. These tumors and tumor-like lesions demonstrate characteristic histopathology, immunocytochemistry and biological behavior. While cross-sectional imaging studies allow detection, staging and limited characterization of these splenic lesions, histopathological confirmation permits optimal management and surveillance strategies.

EBV-positive inflammatory follicular dendritic cell sarcoma of the colon with clonal immunoglobulin gene rearrangement: A case report and literature review

Introduction

Epstein-Barr virus-positive (EBV+) inflammatory follicular dendritic cell (FDC) sarcoma is a rare neoplasm characterized by spindle-shaped follicular dendritic cells, marked lymphoplasmacytic infiltration, and a consistent link to EBV. While it typically affects the liver and spleen, it is exceptionally rare in the digestive tract. We present a special case of EBV + inflammatory FDC sarcoma arising in the colon with clonal immunoglobulin (IG) gene rearrangement.

Case presentation

A 70-year-old man presented with a one-month history of abdominal distension. Colonoscopy revealed a pedunculated polyp in the ascending colon, which was subsequently removed via endoscopic polypectomy. Histological examination of the colonic polyp demonstrated a pronounced lymphoplasmacytic infiltrate with scattered EBV + neoplastic cells, as evidenced by EBV-encoded small RNA in situ hybridization (EBER ISH). The neoplastic cells were positive for FDC-specific markers, including CD21, CD35, and CD23. Additionally, the tumor exhibited clonal rearrangement of the immunoglobulin heavy chain (IGH) gene. The diagnosis was confirmed as EBV + inflammatory follicular dendritic cell sarcoma.

Conclusions

We described an exceptional case of EBV + inflammatory FDC sarcoma presenting as a colonic polyp, featuring a clonal IGH gene rearrangement not previously documented in this colonic tumor type. Heightened awareness of this rare neoplasm within the gastrointestinal tract is essential for both accurate diagnosis and effective patient management.

Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma with significant granuloma: case report and literature review

BACKGROUND

Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma (EBV+IFDCS) is a rare disease characterized by mild clinical symptoms and non-specific imaging findings. The diagnosis of the disease depends on pathological diagnosis. However, EBV+IFDCS has a very broad spectrum of histological morphology and immune phenotypes, and its histopathological features have not been fully described by pathologists.

CASE PRESENTATION

A 59-year-old female, with no significant discomfort, was found to have a splenic mass during a routine physical examination. Microscopic examination at low magnification revealed numerous epithelioid granulomas, amidst which a substantial inflammatory response was observed. Interspersed among the dense inflammatory cells were spindle or oval-shaped cells, distributed sporadically with indistinct boundaries. Under high magnification, these spindle cells had subtle features: smooth and clear nuclear membranes, inconspicuous small nucleoli, and infrequent mitotic figures. Immunophenotypically, the spindle cells expressed CD21 and CD23, and Epstein-Barr encoding region (EBER) in situ hybridization yielded positive results. The inflammatory milieu predominantly consisted of T cells, with a minority of plasma cells expressing IgG4. The confluence of morphological and immunohistochemical findings led to the final pathological diagnosis of EBV+IFDCS in this case.

CONCLUSIONS

The presentation of EBV+IFDCS with pronounced granulomatous changes is rare. This morphological variant poses a high risk of misdiagnosis, frequently leading to confusion with other granulomatous diseases. Accurate diagnosis necessitates a comprehensive analysis, integrating immunohistochemistry and in situ hybridization. The case presented here is instrumental in raising awareness and understanding of EBV+IFDCS, with the goal of reducing misdiagnoses and unrecognized cases.

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.

Imaging findings of Epstein-Barr Virus-positive inflammatory follicular dendritic cell sarcoma of spleen: A case report

BACKGROUND

Spleen Epstein-Barr Virus (EBV)-positive inflammatory follicular dendritic cell sarcoma (FDCS) is rare, and the imaging signs are unclear. The COVID-19 has been confirmed to be the cause of pneumonia and can cause a variety of diseases including myocarditis. However, it has not been reported to be the cause of the exacerbation or activation of EBV-positive inflammatory FDCS.

OBJECTIVE

The objective is to extract the imaging features of EBV-positive inflammatory FDCS in the spleen and analyze the reasons for the special features of this case.

METHODS

By analyzing the patient's treatment process and imaging examinations (A 77-year-old female was admitted to the hospital due to generalized discomfort and pain symptoms. When she was admitted to the hospital a year earlier with COVID-19 pneumonia, a chest CT scan showed that she had a splenic tumor. During this admission, CT scans showed two irregularly shaped and unevenly dense soft tissue density masses within the spleen, with uneven enhancement on contrast-enhanced im-aging within the solid components and along the edges. PET/CT scans revealed elevated glucose metabolism in the masses. Postoperative pathological diagnosis confirmed splenic EBV-positive inflammatory FDCS.), reading the literature, sorting out the disease cognitive process, epidemiology, and pathological data of EBV-positive inflammatory FDCS, we discussed the imaging manifestations and possible differential diagnosis of the disease.

RESULTS

The patient was finally diagnosed with splenic EBV-positive inflammatory FDCS.

CONCLUSIONS

Imaging features of EBV-positive inflammatory FDCS in the spleen include a high incidence of hemorrhage and necrosis, persistent moderate enhancement of the solid portion, a "capsular-like enhancement" structure at the tumor edge, and possibly active glucose metabolism with high Standardized Uptake Values (SUVs). COVID-19 infection and long-term COVID-19 sequelae may exacerbate and activate EBV-positive inflammatory FDCS in the spleen, and the mechanism remains to be further studied.

Case Report: Identification of a novel STAT3 mutation in EBV-positive inflammatory follicular dendritic cell sarcoma

EBV-positive inflammatory follicular dendritic cell sarcoma (EBV+ IFDCS) is an uncommon disease primarily observed in Asia. It is characterized by the development of tumors believed to originate from follicular dendritic cells (FDC). The consistent association between this condition and clonal EBV infection suggests EBV's involvement as an etiological factor. However, diagnosing EBV+ IFDCS can be challenging due to its morphological variability and diverse immunohistochemical staining patterns. The genetic characteristics of EBV+ IFDCS remain insufficiently understood. To address this knowledge gap, we present a case study of a 47-year-old male patient diagnosed with EBV+ IFDCS. We utilized a Next-generation sequencing (NGS) platform to investigate the genetic profile of the tumor cells. We identified a single pathogenic mutation (G618R) in the STAT3 gene. This finding provides valuable insights into the genetic alterations associated with EBV+ IFDCS and potentially contributes to our understanding of the disease's pathogenesis.

Aggressive Variant of Hepatic Epstein-Barr Virus-Associated Inflammatory Pseudotumor-like Follicular Dendritic Cell Sarcoma with PD-L1 and SSTR2a Expression

An aggressive Epstein-Barr virus (EBV)-associated inflammatory pseudotumor-like follicular dendritic cell (IPT-like FDC) sarcoma is reported in an adult female. The patient developed multifocal recurrence and passed away 13 months after the initial surgical resection. A bright field microscopic examination of the tumor demonstrated a classical growth pattern and the diffuse expression of Programmed death ligand 1 (PD-L1) and somatostatin receptor 2a (SSTR2a).