Pseudotumor-like Follicular Dendritic Cell Tumor Research Articles

Inflammatory pseudotumor-like follicular dendritic cell tumor of liver: a report of one case

Inflammatory pseudotumor-like follicular dendritic cell tumor of liver: a report of one case

Inflammatory Pseudotumor-like Follicular Dendritic Cell Tumor of Liver and Spleen

Inflammatory pseudotumor-like follicular dendritic cell (FDC) tumor is an uncommon, Epstein-Barr virus-associated neoplasm of the liver or spleen, characterized by spindly tumor cells dispersed in a background of small lymphocytes and plasma cells. We report 6 diagnostically challenging cases in which the neoplastic component is further overshadowed by granulomas or eosinophils. The patients included 2 men and 4 women with a median age of 45.5 years, and 1 of them showed concurrent involvement of the liver and spleen. The presence of extensive coalescent epithelioid granulomas in 3 splenic tumors and 3 liver tumors raised the possibilities of an infective process or sarcoidosis. In another liver tumor, the massive infiltrate of eosinophils, accompanied by geographic eosinophilic abscesses, suggested parasitic infestation or so-called eosinophilic granuloma of the liver. However, scrutiny of the tissue between the granulomas or among the eosinophils revealed scattered atypical spindly cells with indistinct cell borders, large vesicular nuclei, and distinct nucleoli. The atypical cells were positive for FDC markers on immunostaining (CD21, CD35) and Epstein-Barr virus on in situ hybridization. Thus, a diagnosis of inflammatory pseudotumor-like FDC tumor could be confirmed. Awareness of the granulomatous and eosinophil-rich variants of this tumor type will facilitate the correct diagnosis to be made.

Imaging Findings of Inflammatory Pseudotumor-Like Follicular Dendritic Cell Tumor of Spleen

Inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDCT) histology is similar to that of the classical follicular dendritic cell (FDC) tumor, but, in addition, the inflammatory component is quite prominent. We report a case of IPT-like FDCT of the spleen by abdominal CT and 18F-FDG PET/CT. Abdominal CT showed a low-density, round, well-circumscribed defined mass in spleen, and the mass showed a high metabolism rate on 18F-FDG PET/CT.

Inflammatory Pseudotumor-like Follicular Dendritic Cell Tumor of the Spleen with Extensive Histiocytic Granulomas and Necrosis: A Case Report and Literature Review

Inflammatory pseudotumor (IPT)-like follicular dendritic cell tumor (FDCT) has been recently designated1 and characterized by proliferation of Epstein-Barr virus (EBV)-positive follicular dendritic cell (FDC) and commonly occurs in the liver and spleen.2-9 Histologically, it is characterized by spindle cell proliferation admixed with abundant inflammatory cells, mainly lymphocytes and plasma cells. At present, the preferred term 'inflammatory myofibroblastic tumor' is used, because it has been shown that the proliferating spindle cells show a myofibroblastic phenotype in many cases.1 About 20 cases have been reported,2,9 although only one case has been reported in Korea.9 We present here a rare case of IPT-like FDCT of the spleen with extensive histiocytic granulomas and necrosis, including a brief literature review.

Inflammatory pseudotumor-like follicular dendritic cell tumor of the liver with expression of estrogen receptor suggests a pathogenic mechanism: a case report and review of the literature

The term inflammatory pseudotumor-like follicular dendritic cell tumor has been suggested for a follicular dendritic cell tumor of the liver associated with a dense inflammatory infiltrate and Epstein–Barr virus infection. This tumor is less aggressive than usual intraabdominal follicular dendritic cell sarcoma and shows a strong female predominance; however, the pathogenesis is uncertain. We report the case of a 59-year-old woman who presented with a 6-cm mass in the liver. Histological examination showed spindle cells with a storiform pattern and prominent inflammatory infiltrate mimicking inflammatory pseudotumor. Spindle cells expressed follicular dendritic cell markers CD21 and CD35, and were positive for Epstein–Barr virus-encoded RNA and LMP-1 protein. In addition, neoplastic cells expressed estrogen receptor (ER). Fifteen cases of inflammatory pseudotumor-like follicular dendritic cell tumor of the liver including the case we describe here have been reported in the literature. A review of the literature disclosed that normal follicular dendritic cells may express ER; however, extensive testing has not been previously reported in follicular dendritic cell sarcoma. The female predominance and the expression of ER in the case we report are suggestive of a hormonal role in the pathogenesis and therapy of inflammatory pseudotumor-like follicular dendritic cell tumor of the liver.