ABSTRACT
Follicular dendritic cell (FDC) tumor is an uncommon neoplasm. It generally presents as a slow-growing, painless mass, without systemic symptoms. Histological features usually include low grade spindle cell proliferation. This tumor occurs primarily in lymph nodes, especially cervical and axillary, however, involvement of extranodal sites such as the tonsils, spleen, liver, and gastrointestinal tract has been reported. Inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDCT) is a rare, distinctive histological subtype of this low-grade malignant neoplasm, with consistent Epstein-Barr virus (EBV) association. The differential diagnosis with other fibro-inflammatory tumor proliferations, as inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT), may be challenging. In the present article, two cases of IPT-like FDCT of the spleen are presented, with a broad overview of the literature: one 77-year-old male and one 70-year-old female. A large immunohistochemical panel should be used for diagnosis, as no single specific and totally sensitive markers are available, including markers for CD21, CD23, CD35, CNA42, and clusterin. Individual cases may express one or more of these markers, so that all of them should be investigated. In situ hybridization for EBV is constantly positive. Immunostaining for ALK should be negative, as it is present in roughly half of the cases of IMT. This panel should be used in combination of clinical, laboratory, and topographic evidences. Importantly, inclusion of this lesion as a possible option in clinical and pathological investigation represents the basis for a correct diagnosis (AU)
Subject(s)
Humans , Splenic Neoplasms , Immunohistochemistry , Dendritic Cells, Follicular , Cell Proliferation , Myofibroblasts , Granuloma, Plasma CellABSTRACT
Objective To study the clinicopathological features and biological behavior of inflammatory pseudotumor-like follicular dendritic cell tumor.Methods We studied the clinical data,HE sections,immunohistochemical staining,Epstein-Barr virus encoded nuclear RNA(EBER)in situ hybridization and outcome of one patient with inflammatory pseudotumor-like follicular dendritic cell tumor of liver,and thirteen patients with inflammatory pseudotumor of liver and spleen treated at the Shengjing Hospital of China Medical University from 2001 to 2010.Results Among the thirteen inflammatory pseudotumors,we diagnosed 1 patient with inflammatory pseudotumor-like follicular dendritic cell tumor of spleen and 1 patient with inflammatory pseudotumor-like follicular dendritic cell tumor of liver using immuno-histochemical staining and EBER in situ by hybridization.The liver case had pathological morphology consistent with those described in the literatures,but the splenic case had specific histologic features.They were both female,and were alive 2.5 and 6 years after operation.Conclusions Inflammatory pseudotumor-like follicular dendritic cell tumor should be distinguished from inflammatory pseudotumor.It is a rare tumor seen mainly in liver and spleen.The diagnosis depends on histopathological and immunohistochemical findings.Inflammatory pseudotumor-like follicular dendritic cell tumor is a low-grade malignant tumor.Surgical excision is the treatment of choice.The two cases provided evidence for its indolent behavior.
ABSTRACT
We report a case of an Epstein-Barr virus (EBV)-associated inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDC tumor). The tumor occurred in the spleen of a 64-year-old woman with a history of a diffuse large B-cell lymphoma (DLBCL) of neck nodes that presented four years ago. The splenectomy specimen revealed a 5 cm-sized, tan-colored and well-circumscribed mass. Histologically, spindle or ovoid cells with large vesicular nuclei were admixed with abundant inflammatory cells. Immunohistochemically, spindle cells were positive for FDC marker CD35, but negative for CD20, CD30 and ALK. EBV was detected almost exclusively in spindle cells by EBER in situ hybridization. IPT-like FDC tumors are rare, and are recognized as a distinctive clinicopathologic variant of FDC tumors. Among only 18 similar cases reported in the English language literature, the present case is the first case of a patient with a history of DLBCL.