Follicular dendritic cell sarcoma: A diagnostic challenge !

Abstract

Follicular dendritic cell sarcoma (FDCS) is a spindle cell neoplasm of histiocytic-dendritic cells origin. It is known to occur in lymph nodes and rarely has been reported in extranodal tissues like head and neck, mediastinum and gastrointestinal tract. We herein report the first FDCS arising from anal canal in a 56-year-old man. The tumor was composed of bland short spindle cells in focal whorl formation with interspersed few lymphocytes. The tumor cells were classically positive for CD21, CD23, CD35 and vimentin. Despite its misleading morphology, immunohistochemistry helped us to reach a conclusive diagnosis for relevant therapy.

A 46-year-old Chinese woman presenting with retroperitoneal follicular dendritic cell sarcoma: a case report

“…Pathological diagnosis is challenging [10] and may require a combination of morphological, immunophenotypical, cytochemical and electronmicroscopic analyses [2]. FDCS may be suspected if the tumor exhibits distinct microscopic features, such as a storiform arrangement of spindle-shaped cells, indistinct cell borders and a background of lymphocytes scattered throughout the neoplastic cells [11].…”

An unusual case of follicular dendritic cell sarcoma of the omentum with pleomorphous morphology and aberrant cytokeratin expression

“…Among the latter, the omentum as a primitive site, as recently observed by us, has been exceptionally reported [6,7]. FDCS often represents a diagnostic challenge [8][9][10]. Herein, we reported a rare case of extranodal FDCS, for which the omentum was supposed as the primary site.…”

“…Nevertheless, the diffuse expression of follicular dendritic cell markers was typical for FDCS. Indeed, FDCS may mimic a large spectrum of tumors such as undifferentiated carcinoma, pleomorphic sarcoma, thymoma, and gastrointestinal stromal tumor, so that the differential diagnosis from other malignancy may be so extensive that a very large immunohistochemical panel, including markers for accessory histiocyte/follicular dendritic cell markers, is necessary in order to define the correct cellular lineage [1,4,[8][9][10]. As a matter of fact, every surgical pathologist/hematopathologist should be aware of including the FDCS into the differential diagnosis of any tumor with undifferentiated morphology composed by large "epithelioid polygonal" pleomorphic cells and large eosinophilic cytoplasm.…”

Cervico-Mediastinal Follicular Dendritic Cell Tumor: A Diagnostic and Therapeutic Challenge

“…are the relative paucity of necrosis/ hemorrhage and the presence of coarse calcification) may help distinguishing FDC from bulky mediastinal masses such as lymphoma or small cell lung cancer, FDC sarcoma diagnosis can be awkward [4,9,10]. The differential diagnosis is based on immune histochemichal positivity to CD21, CD23, and CD35, along with podoplanin and cluster in [4,9,10]. The absence of immune histochemical stain was probably the cause of the likely wrong diagnosis (diffuse mixed B-cell lymphoma) performed in our patient in 1987.…”

“…Mitotic figures were not identified. Histological examination was positive for FDC sarcoma with immunohistochemical staining CD21+; CD23-; CD1a-; S100-; CD20-; CD3-; MPX-; CD34-; EMA- [4].…”