ABSTRACT
A 75-year-old man developed l-dopa non-responsive parkinsonism, supranuclear ophthalmoplegia, neck dorsiflexion, and dementia. Atrophy of the midbrain tegmentum on MRI and normal myocardial uptake of MIBG led to the clinical diagnosis of progressive supranuclear palsy (PSP). Autopsy revealed depigmentation of the substantia nigra and locus ceruleus. Alzheimer's disease pathology was advanced with PSP-like neurofibrillary tangles distribution, and Lewy bodies were abundant in limbic lobe, while scarce in lower brainstem nuclei. Tuft-shaped astrocytes were not apparent. Although decreased myocardial uptake of MIBG is a rule in patients harboring Lewy bodies, its normal uptake may be related to their absence in lower brainstem nuclei.
Subject(s)
3-Iodobenzylguanidine , Alzheimer Disease/diagnosis , Lewy Bodies/pathology , Limbic System/pathology , Substantia Nigra/pathology , Supranuclear Palsy, Progressive/diagnosis , 3-Iodobenzylguanidine/metabolism , Aged , Alzheimer Disease/complications , Alzheimer Disease/metabolism , Diagnosis, Differential , Humans , Lewy Bodies/metabolism , Limbic System/metabolism , Magnetic Resonance Imaging , Male , Myocardium/metabolism , Substantia Nigra/metabolism , Supranuclear Palsy, Progressive/complications , Supranuclear Palsy, Progressive/metabolismABSTRACT
Mixed neuronal-glial tumors of the central nervous system display a wide spectrum of differentiation. Among them, the papillary glioneuronal tumor (PGNT) is characterized by pseudopapillary structures composed of astroglial cells covering hyalinized vessels, and by neurocytic, ganglioid and ganglion cells. In addition, a "nonspecific" cell type, not similar to either astrocytes or neurocytes, has been recognized since the initial reports. Recently, minigemistocytic cells and a population immunostained by anti-Olig2 antibody have also been recognized in PGNT. Olig2 is a transcription factor that is specific for the cellular phenotype of oligodendrocytes. The aim of this study was to further investigate the histological diversity of PGNT. We examined six cases of PGNT, each of which showed Olig2 immunopositivity. Minigemistocytes were encountered in three cases at close proximity to the Olig2-positive area. Olig2-positive cells were negative for glial fibrillary acidic protein (GFAP) and neuronal nuclear antigen by double immunostaining, and mainly occupied the interpapillary area laterally adjacent to the GFAP-positive cells. They had relatively small, round and vesicular nuclei, and were formerly regarded as neurocytic cells or nonspecific cellular elements. Fluorescence in situ hybridization targeting chromosome 1p failed to demonstrate any deletion. This study disclosed an additional cellular component of PGNT that is characterized by Olig2 positivity, suggestive of oligodendroglial phenotype, and the results also encourage us to investigate oligodendroglial participation in various glioneuronal tumors.
