Extranodal follicular dendritic cell sarcoma: A clinicopathological report of four cases and a literature review

Abstract

The aim of the present study was to characterize the clinicopathological features of follicular dendritic cell sarcoma (FDCS), and to report the experience of the Xin Hua Hospital Affiliated to Shanghai Jiaotong University School of Medicine (Shanghai, China) with this entity. The clinicopathological findings of four cases that had recently been encountered and 142 previously reported cases in the English literature were evaluated. The current tumors were found in two male and two female patients, aged 49–76 years old, who exhibited a mean tumor size of 8.7 cm. Three of the four cases were misdiagnosed during the initial diagnosis and one experienced intra-abdominal recurrence six months after the first diagnosis. Assessment of all 142 cases in the literature revealed a mild female predominance. The tumors exhibited a mean tumor size of ~7.0 cm. Histologically, the tumors were composed of plump spindle- or oval-shaped cells that exhibited eosinophilic cytoplasm and were arranged in sheets, storiform patterns or whorls. Immunohistochemically, the neoplastic cells expressed at least one of the FDC markers. Among the 130 cases with follow-up data, the overall recurrence, metastasis and mortality rates were 49.2% (64 cases), 21.5% (28 cases), and 13.8% (18 cases), respectively. FDCS can appear deceptively similar to other soft-tissue tumors, even poorly-differentiated carcinomas. A correct diagnosis requires a high degree of suspicion and immunohistochemical evaluation.

Follicular dendritic cell tumour/sarcoma: a commonly misdiagnosed tumour in the thorax

“…Although the lung is a common site for metastasis of FDCS, only seven primary cases have been reported (Table ) . We describe one further case who presented with symptoms reflecting airway compression, with incorrect presurgical diagnosis of ‘suspicious for non‐small cell carcinoma’ based on an epithelioid tumour, but with negative lung cancer‐associated markers (cytokeratins, P40, TTF‐1).…”

“…Histologically, our data are similar to those in the literature, with variable pleomorphism, mitotic activity and necrosis. 6,14,[23][24][25] Of note, a mitotic rate of 20 per 10 HPFs was seen in one case with multiple recurrences and one case that could not be resected completely due to spinal involvement, as seen in other studies where a higher mitotic rate suggests more aggressive behaviour. 25,26 Although the lung is a common site for metastasis of FDCS, 27 only seven primary cases have been reported (Table 5).…”

“…25,26 Although the lung is a common site for metastasis of FDCS, 27 only seven primary cases have been reported (Table 5). 6,14,[23][24][25]28 We describe one further case who presented with symptoms reflecting airway compression, with incorrect presurgical…”

“…Its aetiology is also not known, although Epstein–Barr virus (EBV) has been associated with a specific subset of FDCS presenting in liver and spleen and there are reports of FDCS being associated with the hyaline‐vascular type of Castleman's disease (HVCD) …”

“…Its aetiology is also not known, although Epstein-Barr virus (EBV) has been associated with a specific subset of FDCS presenting in liver and spleen 5,6 and there are reports of FDCS being associated with the hyaline-vascular type of Castleman's disease (HVCD). 7 Herein, we review our experience of clinical, imaging and pathological presentations of FDCS in the thorax, in particular assessing the breadth of immunophenotype and pitfalls in preresection diagnosis and its association with HVCD.…”