Jens Schittenhelm
and the other was located in the arachnoidal space of the left frontal lobe in a 49-year old male (Wiener and Dallgaard 1959 ) .
In contrast there are at least seven known adre- nal cortical adenomas (Schittenhelm et al. 2009 ) . All of them had oncocytic changes and were located in the lumbar region and in two cases were associated with a lipoma (Kepes et al. 1990 ; Karikari et al. 2006 ) . Typically they adhere to lower lumbar spinal nerve roots, but are also seen in an intramedullary site (Cassarino et al. 2004 ; McLendon and Cummings 2006 ) . All except one case were female and there is no age predilection, spanning the spectrum from 8 to 63 years (Mitchell et al. 1993 ) . However, the actual num- bers may be underestimated as there are cases classifi ed either as oncocytoma of the spinal cord or oncocytic paraganglioma without sustenticular cells (Kim et al. 2001 ; Park et al. 2002, 2007 ) . Moran et al. ( 1997 ) examined 30 spinal paragan- gliomas and noted eosinophilic granular cells in two cases “suggestive of oncocytic metaplasia”.
So far all of the intraspinal oncocytic adrenocor- tical adenomas behaved in a benign manner and were cured by gross total resection. There were no reports of tumor recurrence for up to 11 years (Kepes et al. 1990 ) .
Diagnosis
Grossly the tumors appear to be smooth encapsu- lated lesions of grey to brown color. On histology the tumors consists of large round to polygonal epi- thelial cells arranged in nests and cords (Fig. 10.1 ).
The cytoplasm of the cells is pale eosinophilic and the cells appear granular with very faint positivity in PAS stains. Nuclei are mainly round and regular, but focally giant hyperchromatic nuclei may be present. Mitotic activity is low and other histo- logical criterias of malignancy for adrenal tumors such as invasion or necrosis are absent (Lin et al. 1998 ; Bisceglia et al. 2004 ) . Immuno- histochemistry is typical of adrenal cortical tumors with variable expression of cytokeratins (mainly cytokeratins 8 and 18) and positive stains for Melan-A, alpha-inhibin, neuron-specifi c enolase,
synaptophysin and steroidogenic factor 1. In contrast, Chromogranin, S-100 and HMB45 are negative. The proliferation index (Ki-67) is low, normally not exceeding 5% of the tumor cells.
Electron microscopy typically shows abundant mitochondria in the tumor cells.
Differential diagnosis includes other tumors that are known to have oncocytic changes as paraganglioma, meningioma, alveolar soft part sarcoma, granular cell tumor and carcinoma.
Paraganglioma normally have a chromogranin expression and S-100-positive sustentacular cells.
Oncocytic meningiomas and alveolar soft part sarcomas lack the synaptophysin expression seen in cortical adenomas. Granular cell tumors are usually strongly S-100 and PAS-positive.
To confi rm the adrenocortical origin of the tumors, radioimmunoassay for androstenedione or enzy- matic determination of 3 [beta] hydroxysteroid dehydrogenase can be employed. Other methods include immunostains for adrenal steroidogenic enzymes as P-450-11 [beta] hydroxylase, P-450- 21 hydroxylase and P-450-17 [alpha] hydroxylase.
In electron microscopy the oncocytic nature of these tumors corresponds to numerous enlarged mitochondria with osmiophilic lysosomes. Finally the possibility of a metastatic adrenal cortical tumor should always kept in mind, thus clinical examination of the adrenal glands is justifi ed in these cases.
Fig. 10.1 Oncocytic adrenal cortical adenoma is charac- terized by large polygonal, eosinophilic cells with abundant granular cytoplasm and round to ovoid inconspicious looking nuclei
References
Bisceglia M, Ludovico O, Di Mattia A, Ben-Dor D, Sandbank J, Pasquinelli G, Lau SK, Weiss LM (2004) Adrenocortical oncocytic tumors: report of 10 cases and review of the literature. Int J Surg Pathol 12:231–243 Cassarino DS, Santi M, Arruda A, Patrocinio R, Tsokos M,
Ghatak N, Quezado M (2004) Spinal adrenal cortical adenoma with oncocytic features: report of the fi rst intramedullary case and review of the literature. Int J Surg Pathol 12:259–264
Drut R, Quijano G, Altamirano ME, Jones MC, Maffessoli OB (2006) Vascular malformation and choroid plexus adrenal heterotopia: new fi ndings in Beckwith- Wiedemann syndrome? Fetal Pediatr Pathol 25:191–197 Karikari IO, Uschold TD, Selznick LA, Carter JH,
Cummings TJ, Friedman AH (2006) Primary spinal intramedullary adrenal cortical adenoma associated with spinal dysraphism: case report. Neurosurgery 59:E1144
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of seven cases and review of the literature. Am J Surg Pathol 22:603–614
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81 M.A. Hayat (ed.), Tumors of the Central Nervous System, Volume 6: Spinal Tumors (Part 1),
Tumors of the Central Nervous System 6, DOI 10.1007/978-94-007-2866-0_11,
© Springer Science+Business Media B.V. 2012
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Abstract
Chordomas are challenging tumours which usually occur in the axial skeleton, and are particularly diffi cult to manage when they are situated in the clivus and upper cervical spine due to the proximity of eloquent struc- tures. They also have a tendency for local recurrence since enbloc resec- tion is rarely possible in these locations. They have characteristic radiological appearances on MRI, and pathologically are characterised by the presence of Physallipherous cells. The mainstay of treatment is maxi- mal tumour excision at the time of fi rst presentation, followed by high dose radiation treatment such as proton beam irradiation.
Keywords
Chordoma • Cervical spine • Clivus • Tumor • Surgery
Introduction
Chordomas were probably fi rst described by Virchow in 1857 (Crockard 1985 ) . They are tumours which develop from rests of embryonal notochord remnants, and are usually found in the axial skeleton, most commonly in the clivus and sacrum, accounting for 1–8% of primary malig- nant bone tumours and 20% of spinal primary tumours (Crockard and Johnston 1993 ) . The inci- dence in Caucasians is 0.5 per million, and they typically occur in the 30–50 year old age group,
with a roughly equal sex distribution, whereas spinal chordomas tend to occur slightly later, and more commonly in males (James and Crockard 1991 ) . Fifty percent of chordomas occur in the sacrum, 35% in the skull base, and 15% in other parts of the spine.
The bones of the skull base are pre-formed in cartilage and then undergo enchondral ossifi ca- tion, although the orbital roof and greater wings of the sphenoid form from intramembraneous ossifi cation. Chordomas arise from notochordal remnants within the bones of the skull base and spine. In the human, the notochord is a longitudi- nal structure that develops from day 17 and degenerates by week 10, although remnants of it persist in the nucleus pulposus of the cartilagi- nous discs. Its role is to control segmentation of
D. Choi (*)
National Hospital for Neurology and Neurosurgery , Queen Square , London , UK
e-mail: [email protected]