Atypical teratoid/rhabdoid tumor involving cerebrospinal fluid: a case report.

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive tumor of the central nervous system. It is primarily seen in younger age-groups, and the cytomorphology has only been infrequently described. CASE: We present a case of AT/RT arising in the cervical spine of a 6-month-old boy. The cerebrospinal fluid (CSF) cytology and correlating findings are described. The CSF cytomorphologic findings of the AT/RT cells are most notably large cells, eccentrically placed pleomorphic nuclei, prominent nucleoli and, commonly, cytoplasmic inclusions, as well as a second population of smaller mononuclear cells with minimal cytoplasm. CONCLUSION: The cervical spine is a rare site for AT/RT to arise. It is important for pathologists to recognize the cytomorphologic features of AT/RT in the CSF of patients with this tumor to help determine prognosis and disease progression.

Confocal Raman microscopy for monitoring chemical reactions on single optically trapped, solid-phase support particles.

Optical trapping of small structures is a powerful tool for the manipulation and investigation of colloidal and particulate materials. The tight focus excitation requirements of optical trapping are well suited to confocal Raman microscopy. In this work, an inverted confocal Raman microscope is developed for studies of chemical reactions on single, optically trapped particles and applied to reactions used in solid-phase peptide synthesis. Optical trapping and levitation allow a particle to be moved away from the coverslip and into solution, avoiding fluorescence interference from the coverslip. More importantly, diffusion of reagents into the particle is not inhibited by a surface, so that reaction conditions mimic those of particles dispersed in solution. Optical trapping and levitation also maintain optical alignment, since the particle is centered laterally along the optical axis and within the focal plane of the objective, where both optical forces and light collection are maximized. Hour-long observations of chemical reactions on individual, trapped silica particles are reported. Using two-dimensional least-squares analysis methods, the Raman spectra collected during the course of a reaction can be resolved into component contributions. The resolved spectra of the time-varying species can be observed, as they bind to or cleave from the particle surface.