ABSTRACT
Objective:To explore the CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma (FDCS) of the spleen.Methods:The clinical data of 12 patients with splenic inflammatory pseudotumor like FDCS admitted to 3 central hospitals including Yongjia People's Hospital in Zhejiang Province from January 2015 to December 2022 were retrospectively analyzed, including 4 males and 8 females, with a median age of 60 years old. The number, shape, size and CT features of the lesions were analyzed based on patient's CT image data.Results:CT scans of 12 patients showed 15 lesions, including 10 single lesions and 2 multiple lesions. The lesions were circular in 5 cases, elliptical in 4 cases, and irregular in 3 cases. The median maximum diameter of the mass is 6.5 cm. On plain scan, all 12 tumors showed low density or slightly low density. The CT value is (41.3±7.2) HU; 8 cases had uneven density and 4 cases had uniform density. There were 8 cases with clear tumor boundaries and 4 cases with unclear boundaries. There were 8 cases with tumor necrosis and cystic transformation, and 5 cases showed patchy bleeding lesions in the center of the tumor. Enhancement: the arterial phase shows small patches or flocculent enhancement at the edges or parenchymal parts of the tumor, with CT value of (56.0±3.8) HU. Among them, there were 7 cases of mild enhancement, 4 cases of moderate enhancement, and 1 case of significant enhancement. During the portal phase, there was mild to moderate persistent small patchy uneven enhancement, with CT value of (62.0±4.3) HU. Among them, there were 8 cases of mild enhancement and 4 cases of moderate enhancement. The delayed phase showed a slow withdrawal of enhancement, with CT value of (45.0±8.2) HU. All 12 cases underwent complete resection and were diagnosed with FDCS through pathological examination.Conclusion:FDCS plain scan shows circular or elliptical uneven low-density masses, with small patches or flocculent light to moderate uneven enhancement in the arterial phase, continuous enhancement in the portal phase, and slow withdrawal in the delayed phase as the main characteristics.
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.