Brain Pathology Case of the Month - August 2007

Contributed by Rudi Beschorner1, Andrei Koerbel2, Jens Schittenhelm1, Jan Kaminsky2, Hubert Loewenheim3, Eva Bueltmann4, Marcos Tatagiba2, Richard Meyermann1, Manfred Wehrmann5
1Institut of Brain Research, 2Department of Neurosurgery, 3Department of Otolaryngology, Head and Neck Surgery, 4Department of Neuroradiology, 5Institut of Pathology, University of Tuebingen, Germany


A 47-year-old woman was admitted to the hospital with a 4-month history of frontal headache that had radiated to her neck. Physical and neurological examinations did not demonstrate any abnormalities.


A CT of the head revealed a destructive, marrow-replacing midline to right-sided lesion of the clivus (Fig. 1) expanding to the right petrous internal carotid artery segment and eroding the right petrous apex. This was confirmed by MRI which showed the lesion to be iso- to hypointense on T1- weighted images (Fig. 2) and hypo- to hyperintense on T2- weighted images (Fig. 3). The post-gadolinium MRI showed heterogeneous enhancement (Fig. 4). The MRI also showed involvement of the extradural space in the prepontine region. After administration of contrast material no further intracerebral lesions were found. Neuroimaging differential included chordoma, chondroma and chondrosarcoma.


The patient underwent a left-sided maxillotomy via a midfacial degloving for a transsphenoidal approach to the clivus and contra-lateral petrous apex. Wide surgical exposure allowed access to the mass. The lesion was almost completely removed. A small portion of the mass located laterally to the right carotid artery was left. The postoperative period was uneventful and the patient could be displaced without neurological deficits.


Macroscopically, the specimens were moderately firm and of grayish color. Pathologic intraoperative frozen section examination showed a few larger vacuolated cells that were considered as compatible with a chordoma (Fig. 5). Microscopic neuropathologic examination of formalin-fixed tissue samples showed mainly mucosal and submucosal tissue with fresh hemorrhages (Fig. 6) and minor parts of bone tissue showing fibrosis of marrow spaces as well as few small areas with cellular infiltration (Fig. 7). These infiltrates consisted mainly of small lymphocytes, some plasma cells and eosinophilic granulocytes (Fig. 8). Furthermore some larger cells (10-25µm) with grooved, folded, indented or lobulated nuclei, with fine to moderately dense chromatin and a moderately abundant slightly eosinophilic cytoplasm were found (Fig. 9). These cells occasionally contained cytoplasmic vacuoles (Fig. 9, arrows) and showed immunoreactivity with antibodies against S100 (Fig. 10), PGM1 (Fig. 11) and CD1a (Fig. 12). No expression of vimentin or pan-cytokeratin was found in these cells. There was no necrosis and only very few mitotic figures.


Further clinical investigations( including bone scan) did not identify any other lesions in the skeletal or soft tissues of the body.


International Society of Neuropathology