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

Abstract

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.

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

“…In a Korean study [ 16 ], a large number of IgG4-positive plasma cells were found in six EBV-positive patients with IPT-like FDCS, suggesting that EBV has a key role in IPT-like FDCS. Three cases of IPT-like FDCS, characterized by IgG4 positivity, EBV positivity, and splenic involvement, were also reported in various studies [ 8 , 14 , 17 ]. Additional markers for FDCS encompass Ki-M4 and CD14 [ 35 ], CXCL13 and clusterin [ 36 ], gamma-synuclein and D2-40 [ 8 , 16 ], podoplanin and the low affinity NGFR [ 37 , 38 ].…”

“…IPT-like FDCS typically follows a painless course and exhibits a more indolent nature compared to classic FDCS. It was noted that IPT-like FDCS exhibits an inert biological behaviour that allows patients to achieve long-term survival even in the event of relapse [ 14 ]. Our findings corroborate this conclusion.…”

“…We have reviewed the existing literature and discussed the disease in light of our findings. To date, there have been 29 published cases [ [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] ] of splenic IPT-like FDCS, all of which have shown an association with EBV proliferation. Yet, the clinical presentation and pathological characteristics of this condition continue to be a subject of debate.…”