Humans ; Dendritic Cells, Follicular ; Castleman Disease/surgery* ; Liver ; Hyperplasia

Colon ; Dendritic Cell Sarcoma, Follicular/surgery* ; Dendritic Cells, Follicular ; Epstein-Barr Virus Infections ; Herpesvirus 4, Human ; Humans

Colon ; Dendritic Cell Sarcoma, Follicular/surgery* ; Dendritic Cells, Follicular ; Granuloma, Plasma Cell/diagnostic imaging* ; Herpesvirus 4, Human ; Humans

Follicular dendritic cell sarcoma (FDCS) is an extremely rare tumor with only 67 cases of head and neck FDCS reported in the literature. A 65-year-old female had a 6-cm follicular dendritic cell sarcoma resected from the left parotid gland with close margins. It recurred 1 year later as a 5-cm mass that was intensely [18F] fluoro-2-deoxy-D-glucose (18F-FDG) avid on positron emission tomography/computed tomography (PET/CT) and was re-excised. A follow-up PET/CT did not show any metastatic disease. The use of 18F-FDG PET/CT in the management of FDCS warrants further research. We present the 18F-FDG PET/CT imaging findings of this rare tumor.
Aged ; Dendritic Cell Sarcoma, Follicular ; Dendritic Cells, Follicular ; Electrons ; Female ; Fluorodeoxyglucose F18 ; Follow-Up Studies ; Head ; Humans ; Neck ; Parotid Gland ; Positron-Emission Tomography and Computed Tomography

Follicular dendritic cell (FDC) sarcoma is rare and is classified either as conventional type or inflammatory pseudotumor (IPT)-like variant. Extranodal presentation is uncommon and nearly all gastrointestinal FDC tumors are of the conventional type. IPT-like variant tumors occur almost exclusively in the liver and spleen and are consistently associated with Epstein-Barr virus (EBV). Here we report the case of a 78-year-old woman with an IPT-like FDC sarcoma presenting as a pedunculated colonic polyp. Histologically, scanty atypical ovoid to spindle cells were mixed with a background of florid lymphoplasmacytic infiltrate, which led to an initial misdiagnosis of pseudolymphoma. These atypical cells expressed CD21, CD23, CD35, and D2-40, and were positive for EBV by in situ hybridization, confirming the diagnosis. The patient was free of disease five months after polypectomy without adjuvant therapy. Although extremely rare, the differential diagnosis for colonic polyp should include FDC sarcoma to avoid an erroneous diagnosis. A review of the 24 cases of IPT-like FDC sarcoma reported in the literature reveal that this tumor occurs predominantly in females with a predilection for liver and spleen, and has a strong association with EBV.
Aged ; Colonic Polyps* ; Dendritic Cell Sarcoma, Follicular* ; Dendritic Cells, Follicular ; Diagnosis ; Diagnosis, Differential ; Diagnostic Errors ; Female ; Granuloma, Plasma Cell ; Herpesvirus 4, Human ; Humans ; In Situ Hybridization ; Liver ; Pseudolymphoma ; Sarcoma ; Spleen ; Taiwan

Syntenin is an adaptor molecule containing 2 PDZ domains which mediate molecular interactions with diverse integral or cytoplasmic proteins. Most of the results on the biological function of syntenin were obtained from studies with malignant cells, necessitating exploration into the role of syntenin in normal cells. To understand its role in normal cells, we investigated expression and function of syntenin in human lymphoid tissue and cells in situ and in vitro. Syntenin expression was denser in the germinal center than in the extrafollicular area. Inside the germinal center, syntenin expression was obvious in follicular dendritic cells (FDCs). Flow cytometric analysis with isolated cells confirmed a weak expression of syntenin in T and B cells and a strong expression in FDCs. In FDC-like cells, HK cells, most syntenin proteins were found in the cytoplasm compared to weak expression in the nucleus. To study the function of syntenin in FDC, we examined its role in the focal adhesion of HK cells by depleting syntenin by siRNA technology. Knockdown of syntenin markedly impaired focal adhesion kinase phosphorylation in HK cells. These results suggest that syntenin may play an important role in normal physiology as well as in cancer pathology.
B-Lymphocytes ; Cytoplasm ; Dendritic Cells, Follicular* ; Focal Adhesion Protein-Tyrosine Kinases* ; Focal Adhesions* ; Germinal Center ; Humans* ; Lymphoid Tissue ; PDZ Domains ; Phosphorylation ; Proteins ; RNA, Small Interfering ; Syntenins*

OBJECTIVETo identify the immunohistochemical patterns of follicular dendritic cell (FDC) meshwork and Ki-67 labeling index in small B-cell lymphomas (SBLs) and their significance in differential diagnosis.

METHODSSixty-eight cases of SBLs were included collected from November 2008 to June 2012. The patterns of FDCs and Ki-67 expression were studied on paraffin sections by CD21, CD23 and Ki-67 immunohistochemistry. The characteristic staining patterns of FDCs and Ki-67 expression among different SBLs were analyzed statistically.

RESULTSThe age of SBL patients ranged from 28 to 85 years with a mean of 55.2 years. The male to female ratio was 1.2:1. Fifty-five cases involved only lymph nodes (80.9%), and the remaining cases involved multiple extra-nodal sites. Histological classification of the cases was made according to the 2008 WHO lymphoma classification criteria: 22 were low-grade follicular lymphomas (FLs, including grade 1 and grade 2), 19 marginal zone lymphomas (MZLs), 17 mantle cell lymphomas (MCLs), and 10 chronic lymphocytic leukemia/small lymphocytic lymphomas (CLL/SLLs). FDC meshwork limited to the central part of neoplastic follicles was characteristic for FL (90.9%, 20/22). The germinal center FDC meshwork was destroyed primarily at periphery in MZL (14/19). The absence or scattered FDC clusters were typical of SLL/ CLL. Irregular FDC was seen in 7/17 of MCL, while 7/17 MCL displayed FDC pattern similar to that of CLL/SLLs. The pattern of FDCs was a significantly diagnostic feature in distinguishing the four types of SBLs (P < 0.01). Ki-67 was also a statistically significant parameter (P < 0.05) with decreasing labeling index as the following: MCL, FL, SLL and MZL. Ki-67 showed scattered pattern in germinal centers with loss of polarity in FLs. MZL presented uniformly scattered positive pattern in interfollicullar areas. Ki-67 staining was uniform in MCL, but its labeling index varied from 5% to 90%. The Ki-67 index was higher in the morphological "proliferation centers" of all CLL/SLLs.

CONCLUSIONImmunohistochemical staining patterns of FDC meshworks and Ki-67 labeling index offer a significant discriminatory power in the differential diagnoses among SBLs.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; Dendritic Cells, Follicular ; pathology ; Diagnosis, Differential ; Female ; Humans ; Immunohistochemistry ; Ki-67 Antigen ; metabolism ; Leukemia, Lymphocytic, Chronic, B-Cell ; metabolism ; pathology ; Lymphoma, B-Cell ; classification ; metabolism ; pathology ; Lymphoma, B-Cell, Marginal Zone ; metabolism ; pathology ; Lymphoma, Follicular ; metabolism ; pathology ; Lymphoma, Mantle-Cell ; metabolism ; pathology ; Lymphoma, Non-Hodgkin ; metabolism ; pathology ; Male ; Middle Aged ; Receptors, Complement 3d ; metabolism ; Receptors, IgE ; metabolism ; Retrospective Studies

No abstract available.
Dendritic Cells, Follicular* ; Granuloma* ; Necrosis* ; Spleen*

Evidence for immunoregulatory roles of prostaglandins (PGs) is accumulating. Since our observation of PG production by human follicular dendritic cells (FDCs), we investigated the regulatory mechanism of PG production in FDC and attempted to understand the functions of released PGs in the responses of adjacent lymphocytes. Here, using FDC-like cells, HK cells, we analyzed protein expression alterations in cyclooxygenase-2 (COX-2) in the presence of IL-4 or histone deacetylase (HDAC) inhibitors. Both IL-4 and HDAC inhibitors suppressed COX-2 expression in dose-dependent manners. Their effect was specific to COX-2 and did not reach to COX-1 expression. Interestingly, HDAC inhibitors gave rise to an opposing effect on COX-2 expression in peripheral blood monocytes. Our results suggest that IL-4 may regulate COX-2 expression in FDCs by affecting chromatin remodeling and provide insight into the role of cellular interactions between T cells and FDC during the GC reaction. Given the growing interests in wide-spectrum HDAC inhibitors, the differential results on COX-2 expression in HK cells and monocytes raise cautions on their clinical use.
Chromatin Assembly and Disassembly ; Cyclooxygenase 2 ; Dendritic Cells, Follicular ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; Histones ; Humans ; Interleukin-4 ; Lymphocytes ; Monocytes ; Prostaglandins ; Stromal Cells ; T-Lymphocytes

BACKGROUND: Understanding the biologic behavior of a tumor is a prerequisite for tumor registration code assignment. The aim of this report was to propose appropriate behavior codes of the International Classification of Disease Oncology 3 (ICD-O3) to rare, yet pathologically interesting hematopoietic and soft tissue tumors. METHODS: The Study Group for Hematopathology, the Bone and Soft Tissue Pathology Study Group, and the Cancer Registration Committee prepared the questionnaire containing provisional behavior codes of selected diseases. RESULTS: In situ lesions of mantle cell and follicular lymphomas, dendritic cell tumors, and neoplasms with perivascular epithelioid cell differentiation (PEComa), not otherwise specified were classified as malignant (-/3). The fibromatosis group, with the exception of lipofibromatosis, was proposed as benign (-/0). Lipofibromatosis and several diseases that belong to the PEComa group were proposed as uncertain malignant potential (-/1). For the hematologic and soft tissue tumors, 274 and 288 members of the Korean Society of Pathologists, respectively, provided opinions through questionnaire, and most responders showed agreement with the provisional behavior code proposed. CONCLUSIONS: The determination of behavior codes for the rare diseases described in this study, especially those of the PEComa group or malignant lymphoma, could be viewed as impractical and premature, but this study provides the basis for future research on this topic.
Dendritic Cells ; Epithelioid Cells ; Fibroma ; Hematologic Neoplasms ; Lymphoma ; Lymphoma, Follicular ; Perivascular Epithelioid Cell Neoplasms ; Surveys and Questionnaires ; Rare Diseases ; Soft Tissue Neoplasms