ABSTRACT
Follicular dendritic cell sarcomas are unusual, and extranodal origin is extremely rare. The English literature contains only eight cases in which this sarcoma has been presented as a tonsillar mass. We report a new case of follicular dendritic cell sarcoma of the tonsil in a 76 year old woman. The patient underwent diagnostic tonsillectomy for a left tonsillar mass, and follicular dendritic cell sarcoma was diagnosed based on histopathological and immunoperoxidase findings. Postoperative radiotherapy was performed. The patient is alive and disease-free at 4 years of follow-up. Without a high index of suspicion, this entity can easily be missed. We believe that follicular dendritic cell sarcoma should be included in the differential diagnosis for any tonsillar mass.
Subject(s)
Dendritic Cells, Follicular/pathology , Sarcoma/pathology , Tonsillar Neoplasms/pathology , Aged , Dendritic Cells, Follicular/radiation effects , Diagnosis, Differential , Female , Humans , Sarcoma/radiotherapy , Sarcoma/surgery , Tonsillar Neoplasms/radiotherapy , Tonsillar Neoplasms/surgery , TonsillectomyABSTRACT
Serum IgE is suppressed in CD23-transgenic (Tg) mice where B cells and some T cells express high levels of CD23, suggesting that CD23 on B and T cells may cause this suppression. However, when Tg B lymphocytes were compared with controls in B cell proliferation and IgE synthesis assays, the two were indistinguishable. Similarly, studies of lymphokine production suggested that T cell function in the Tg animals was normal. However, adoptive transfer studies indicated that suppression was seen when normal lymphocytes were used to reconstitute Tg mice, whereas reconstitution of controls with Tg lymphocytes resulted in normal IgE responses, suggesting that critical CD23-bearing cells are irradiation-resistant, nonlymphoid cells. Follicular dendritic cells (FDC) are irradiation resistant, express surface CD23, and deliver iccosomal Ag to B cells, prompting us to reason that Tg FDC may be a critical cell. High levels of transgene expression were observed in germinal centers rich in FDC and B cells, and IgE production was inhibited when Tg FDCs were cultured with normal B cells. In short, suppressed IgE production in CD23-Tg mice appears to be associated with a population of radioresistant nonlymphoid cells. FDCs that interface with B cells in the germinal center are a candidate for explaining this CD23-mediated IgE suppression.
