Fourteen cases of surgically excised lymphoepithelial cysts (13 from the parotid gland and 1 from the submandibular gland) were reviewed for diagnostic histologic features. They showed squamous epithelium-lined cysts within lymph nodes. Lymphocytes, histiocytes, and plasma cells were found in the walls of the cysts. Multinucleated giant cells were present in four cases. The five patients tested for human immunodeficiency virus (HIV) infection were positive, both by enzyme-linked immunosorbent assay (ELISA) and Western Blot. Fine-needle aspiration (FNA) was performed on five cases (two were confirmed histologically). Diff-Quik-stained smears showed a proteinaceous background and a mixed population of lymphocytes, histiocytes, plasma cells, and metaplastic squamous cells. When the above cytologic findings are present on fine-needle aspiration of a major salivary gland lesion, the diagnosis of lymphoepithelial cyst should be considered.

Genus-specific 16S rRNA targeted oligonucleotide probes, Rco1 and Rco2, were designed and used to detect rhodococci in activated sludge foam samples by confocal laser scanning microscopy. Pure cultures were used to find the optimal hybridisation conditions which were determined by comparing the mean fluorescent intensities of target and non-target cells from images captured using a confocal laser scanning microscope (CLSM). The combination of fluorescent in situ hybridisation with rRNA-targeted oligonucleotide probes and confocal laser scanning microscopy provides an effective way of detecting rhodococci in environmental samples.