Follicular dendritic cell sarcoma with microtubuloreticular structure and virus-like particle production in vitro.

Neoplasm of follicular dendritic cells (FDC), follicular dendritic cell sarcoma (FDCS), is a rare tumor of intermediate to high-grade malignancy in lymph nodes and visceral organs. Reported herein is a case of FDCS arising from cervical lymph nodes in a 16-year-old Japanese boy, who died of the disease 3 years after diagnosis. The tumor cells were pale eosinophilic and elongated with euchromatic nuclei and were positive for CD21, clusterin, and CNA-42 on immunohistochemistry, as well as desmosome-like junctions on electron microscopy. The presence of microtubuloreticular structures (MTRS) in the tumor cells and associated lymphocytes characterized this case, suggesting some viral infection, although qualitative polymerase chain reaction of genomic and complementary DNA obtained from the tumor failed to demonstrate any viral infection at the laboratory level. The stimulation of dispersed tumor cells and peripheral blood mononuclear cells with mAb to CD3 and interleukin-2 was attempted; and the cell line established by the authors (FDCS-Sa) was stimulated with iododeoxyuridine. Virus-like particles (VLP) were successfully induced from each cellular source. The VLP, 100 nm in diameter, showed an electron-dense thorny envelope and granular core. This is the first case of FDCS with MTRS accompanying VLP production in vitro.

Pre-treatment mitotic index versus computer-quantitated Ki-67 nuclear antigen labeling index as predictors of response to neoadjuvant chemotherapy in uterine cervical carcinoma.

In order to evaluate the usefulness of the mitotic index (MI) and the Ki-67 nuclear antigen labeling index (Ki67LI) in pre-treatment biopsy specimens as predictors of response to chemotherapy for uterine cervical carcinomas, twelve patients with squamous cell carcinoma who received neoadjuvant chemotherapy before radical surgery were investigated. The MI and computer-quantitated Ki67LI were determined using H&E and immunostained slides of biopsy specimens collected before chemotherapy. Tumor size was measured three-dimensionally by MR imaging, and assessed before and after chemotherapy. We compared the values of MI and Ki67LI with changes in tumor size and the following results were obtained. 1) The percentage reduction in tumor size ranged from 0 to 98%. The MI ranged from 0.5 to 15, and Ki67LI ranged from 0.01 to 50.1%. 2) A significant positive correlation was observed between response to chemotherapy assessed on MR image and MI [Spearman's correlation coefficient (r) =0.66, n=12, p=0.027], and between response to chemotherapy and Ki67LI (r=0.72, n=12, p=0.017). 3) A significant correlation was observed between MI and computer-assessed Ki67 LI [Pearson's correlation coefficient (r) =0.80, n=12, p=0.002]. Therefore, pre-chemotherapy MI and Ki67LI were both good predictors of response to platinum-based chemotherapy. Because MI is technically more convenient and economically less expensive than computer-quantitated Ki67LI, MI remains a simple and reliable predictor from the clinical point of view.