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

Abstract

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.

Follicular dendritic cell sarcoma of gastrointestinal tract with two emerging distinct subtypes: a case report and systemic review

“…We searched the literature for reported cases of gastrointestinal FDCS and found 32 cases [ 5 , 6 , 8 – 10 , 16 – 35 ]: 20 cases of classic/conventional type and 12 cases of inflammatory EBV+ type. The clinicopathological features of two types are compared in Table 1 .…”

“…Based on the recent findings and emerging evidence of inflammatory EBV+ GI FDCS, we favor the latter classification by their EBV status. Recent reports from different groups identified another 11 cases of EBV+ inflammatory GI FDCS, which are all from Southeast Asia with invariable association with EBV [ 8 – 10 ]. Interestingly enough, these tumors arise exclusively from lower GI tract, presenting as polypoid masses in the colon.…”

“…Classic FDCS is not associated with EBV infection and a subset of cases coexist with or are preceded by hyaline vascular Castleman disease [ 1 , 6 , 7 ]. By contrast, inflammatory EBV+ FDCS consistently demonstrates an association with EBV infection and typically arises in the liver and/or spleen, however more cases have recently been reported in the GI tract [ 8 – 10 ].…”

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

“…Approximately 10% to 20% of FDCS cases are correlated with antecedent or concurrent Castleman disease, which is a benign lymphoproliferative disease, and mostly in the hyaline vascular variant ( 7 ). Two-thirds of FDC sarcomas occur in the lymph nodes, and one-third occur in extranodal sites ( 8 ). Most cases are asymptomatic, and lymphadenopathy is the most common clinical manifestation ( 7 ).…”

Clinicopathologic and molecular analysis of inflammatory pseudotumor-like follicular/fibroblastic dendritic cell sarcoma: a case report and review of literature

“…Inflammatory pseudotumor-like follicular/fibroblastic dendritic cell (FDC/FRC) sarcoma, a subgroup of follicular dendritic cell sarcoma (FDC), is rare neoplasm that often occurs in the spleen (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) . FDC/FRC sarcoma can involve other anatomical sites including the liver (13,(16)(17)(18)(19)(20)(21)(22)(23), colon (24,25), and peripancreas (17,20). The tumor has a predilection for young to middle-age adults and may present with various symptoms including fever, abdominal pain, sweats, fatigue (predominantly in women), and more often splenic solitary lesions (5,6,9).…”