RESUMEN
Neuroendocrine neoplasms are derived from the epithelial lineages mainly of respiratory tract, with predominant neuroendocrine differentiation. There are only a handful of documented cases of paranasal small cell neuroendocrine carcinomas (SNEC) with primary orbital involvement. Here, the authors describe a 33-year-old male patient with rapidly progressive swelling of the right lower lid with proptosis since 4 weeks. On contrast-MRI orbit, an ill-defined multilobulated mass measuring 3.6 × 3.1 cm with intense homogenous enhancement was seen in the right retrobulbar space involving the right ethmoid sinus. On incisional biopsy, a poorly differentiated mass containing numerous small round blue cells and scanty intervening stroma with prominent necrosis and apoptosis was seen. Immunohistochemistry was strongly positive for synaptophysin. He was diagnosed as a case of SNEC and received chemotherapy, with good response till date of 9 months of follow up. The authors present a literature review and describe challenges in management of a primary orbital SNEC.
RESUMEN
In this paper we have used a monoclonal antibody to CD34 an antigen expressed solely on stem cells, and stem cell colony assays to show that umbilical cord blood has nearly the same number of functional stem cells as compared to normal bone-marrow. The number of CD34+ve cells in cord blood being 2 to 2.7 per cent, whereas bone-marrow had 3 to 3.5 per cent. The multi-potent colony forming cells (CFU-GEMM) were 60 +/- 18 in cord blood per 2 x 10(5) mononuclear cells (MNCs), whereas normal bone-marrow had 70 +/- 10 per 2 x 10(5) MNCs. Enrichment of these stem cells on Percoll gradients was successful for normal bone-marrow but not for cord blood.