Survival analysis in patients with follicular dendritic cell sarcoma: a population-based study.

Follicular dendritic cell sarcoma (FDCS) is a rare low-intermediate grade malignant neoplasm. To date, published data on FDCS clinical courses are sparse, and no conditional survival study has been performed. Thus, we retrospectively analyzed 187 patients diagnosed with FDCS from the Surveillance, Epidemiology, and End Results (SEER) database. In this study, the median age at diagnosis was 50 years and 91 (48.7%) patients were male. The most common primary location was the abdomen/pelvis (82, 43.9%). The 1-year, 3-year, and 5-year overall survival (OS) were 88.7%, 69.0%, and 59.8%, respectively. The 5-year conditional overall survival increased from 65.7% at baseline to 83.8% in 5-year survivors. The 3-year FDCS-specific death rate was 26.7% and the rate of death from other reasons was 3.7%. In addition, the annual death hazard was the highest in the first four years after diagnosis and increased again in the 7th and 8th years. Age > 60 years at diagnosis, metastatic disease, and FDCS in thoracic organs were associated with shorter OS and FDCS-specific survival. In addition, FDCS patients, with either local or metastatic disease, could benefit from surgery therapy. In addition, adjuvant radiotherapy or chemotherapy for local disease provided no significant improvement in overall survival or FDCS-specific survival. We hope these findings may guide treatments and surveillance strategies for FDCS patients in clinical practice.

Descriptive Analysis of Histiocytic and Dendritic Cell Neoplasms: A Single-Institution Experience.

PURPOSE: Histiocytic and dendritic cell neoplasms are rare hematologic tumors. This study aimed to describe the epidemiologic features of the entire spectrum of histiocytic and dendritic cell neoplasms, including clinicopathological variables and patient outcomes. MATERIALS AND METHODS: We comprehensively reviewed 274 patients who were diagnosed with histiocytic and dendritic neoplasms at Severance Hospital, Seoul, South Korea between 1995 and 2018. RESULTS: The most common neoplasm was Langerhans cell histiocytosis (LCH), followed by dermal xanthogranuloma. Among non-LCH sarcomas, histiocytic sarcoma (HS) showed a relatively high prevalence, followed by follicular dendritic cell sarcoma (FDCS). Disseminated juvenile xanthogranuloma (DJG), Erdheim-Chester disease (ECD), indeterminate dendritic cell tumor (IDCT), and interdigitating dendritic cell sarcoma (IDCS) rarely occurred. Generally, these tumors presented in childhood, although the non-LCH sarcoma (HS/FDCS/IDCS/IDCT) group of tumors and ECD occurred in late adulthood. Multiorgan involvement and advanced Ann-Arbor stage, as well as recurrence and death of disease, were not uncommon. The non-LCH sarcoma group had the worst overall survival, compared to the DJG, ECD, and LCH groups. CONCLUSION: Our findings indicate that histiocytic and dendritic cell neoplasms exhibit heterogeneous epidemiologic characteristics and that some patients may have unfavorable outcomes, especially those with non-LCH sarcoma.

Splenic Epstein-Barr Virus-Associated Inflammatory Pseudotumor.

Splenic inflammatory pseudotumor (IPT) is an uncommon lesion with an inflammatory morphologic aspect that often poses a diagnostic challenge. The etiology of IPT can be infectious, autoimmune, reactive, or neoplastic. Splenic Epstein-Barr virus (EBV)-associated IPTs form a subset of splenic IPTs in which there is a spindle cell component infected by EBV. The best characterized and most frequent subgroup of splenic EBV-associated IPT is IPT-like follicular dendritic cell tumor. This review also focusses on EBV-associated splenic IPTs without follicular dendritic cell marker expression. These lesions are less well characterized, making the differential diagnosis with other splenic lesions even more difficult. Recently, increased numbers of immunoglobulin G4-positive plasma cells and the presence of numerous granulomas have been reported in EBV-associated IPTs, and this can add to the difficulties in recognizing the neoplastic nature of these lesions. Herein, we also review the epidemiology, clinical features, histologic morphology, immunohistochemistry, electron microscopy, and pathogenesis of EBV-associated IPTs.

Clinical and pathological features of head and neck follicular dendritic cell sarcoma.

OBJECTIVES: Follicular dendritic cell sarcoma (FDCS) in the head and neck is uncommon. The etiology, pathogenesis, optimal treatment, and prognosis are not well understood. In this review, we investigated these features to deepen the understanding of the disease. METHODS: We reviewed FDCS in the head and neck in the English language literature through Medline. We analyzed the clinical characteristics, pathologic features, immunophenotypic profile, and treatments of FDCS. RESULTS: Of 137 reported cases of FDCS in the head and neck region, 127 included data on age and gender. Among those, 64 were females and 63 were males. The mean age was 46 years (9-79 years). In the 106 cases with complete follow-up data, fourteen patients (13.2%) had local recurrence. Fourteen patients (13.2%) had distant metastasis. The metastatic site involved the lung, liver, adrenal, rib, vertebral body, and iliac bone. The overall 5-year survival rate was 80.0%. Compared to nodal FDCS and extranodal FDCS, the overall 5-year survival rates were 71.1 and 85.3%, respectively, with no significance (P = 0.42), 0.8% waived treatment, 46.6% received surgery alone, 30.5% received surgery combined with postoperative radiotherapy, 8.4% received surgery combined with postoperative radiotherapy and chemotherapy, 7.6% received surgery combined with postoperative chemotherapy, 3.1% received chemotherapy alone, 2.2% received chemotherapy combined with radiotherapy, 0.8% received radiotherapy alone. CONCLUSIONS: FDCS in the head and neck is rare. There was no difference in the survival between nodal and extranodal FDCS. The optimal treatment was undetermined.