|Case 14 :|
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shows a hyperdense, minimally enhancing mass lesion in the left superior
nasal cavity, with bony erosion of the adjoining medial orbital wall, and
sphenoid wall involvement. No calcification is noted.
(ENB) is an uncommon malignant neoplasm of neural crest origin arising
from the olfactory sensory epithelium in the roof of the nasal fossa. The
tumor was first described in 1924 by Berger et al, who reported in the
French literature about "l'esthesioneuroepitheliome olfactif."
tends to spread submucosally in all directions to involve the paranasal
sinuses, nasal cavity, and surrounding structures. The tumor is locally
aggressive, and local recurrence strikes in up to 68% of cases regardless
of initial treatment protocol. ENB also metastasizes widely by both
hematogenous and lymphatic routes, with the neck being the most common
features on histology which aid in identification include small, round or
oval blue neuroepithelial cells arranged in true rosette of pseudorosette
patterns, separated by fibrous septa, surrounding stroma composed of
undifferentiated nuclei and neurofibrillary cords; marked microvascularity;
palisading of neuroepithelial cells around vessels. Mitotic figures are
rare, and calcification and necrosis are sometimes seen. Occasionally,
electron microscopy is used to confirm the presence of neuroblastoma.
advent of CT scanning has greatly enhanced the staging accuracy and
therapeutic planning capability with regard to ENB. ENB has no classic
radiologic features, but the tumor is typically a homogenous soft tissue
mass with relatively uniform, moderately intense contrast enhancement,
located in the superior nasal cavity. Bony erosion is frequently seen and
usually accompanied by remodeling. Calcification may be seen.
et al in 1976 devised
the currently popular staging system for ENB.
A: tumor confined to the nasal cavity;
B: tumor involving the nasal cavity and paranasal sinuses;
C: tumor extension beyond the nasal cavity and sinuses.
et al proposed a
staging system based on the TNM classification:
tumor in the nasal cavity and sinuses (except sphenoid) with or without
erosion of anterior cranial fossa bone
periorbital or anterior cranial fossa extension
brain involvement with resectable margins
Primary surgery, primary
radiotherapy, and combined surgery and radiotherapy have been employed
against ENB. Chemotherapy has generally not been the first choice for
resectable ENB, but a multitude of drugs have achieved cytoreduction in
advanced cases in some studies.