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Anne Getz, MD
A 44-year-old man presented with an eighteen-month history of nasal obstruction associated with occasional blood-tinged nasal discharge, and four months of anosmia. Review of systems was positive for occasional mild headaches, excess thirst and urination, and decreased appetite. He denied any visual field loss, diplopia, facial sensory loss or constitutional symptoms.
Physical examination revealed intact visual fields and extraocular movements. His facial sensation was intact, and the remainder of the neurological examination was normal. Endoscopic examination demonstrated a pink mass protruding into the left sphenoethmoidal recess from the sphenoid ostium (Fig. 1).
MRI (Fig. 2) and CT (Figs. 3 and 4) scans showed a large homogeneously enhancing mass expanding the sphenoid sinus, obliterating the sella, with involvement of both cavernous sinuses. The right internal carotid artery within the cavernous sinus was markedly constricted, and the optic chiasm was mildly compressed on the left.
An outside biopsy showed neuroendocrine tumor.
Endoscopic transsphenoidal resection (Fig. 5) was performed with the collaboration of the rhinologist, neurosurgeon and head and neck surgeon. Intraoperative frozen sections demonstrated blue cell tumor. Complete resection was possible. The tumor dissected easily from the sphenoid sinus, carotid and optic canals, and appeared to originate from within the sella (Fig. 6).
Final pathologic analysis revealed pituitary macroadenoma (Fig. 7).
Discussion:
Pituitary adenomas are typically soft, well-circumscribed lesions. They may be confined to the sella turcica, or may extend superiorly through the diaphragm sella into the suprasellar region, laterally into the cavernous sinus or inferiorly into the sphenoid sinus, where they may present as a sphenoid mass, as in this case. Often they may compress adjacent structures, such as the optic chiasm or cranial nerves. Expansile lesion may erode the sella turcica and anterior clinoid processes. One third of such lesions are not well encapsulated. Infiltration of surrounding bone, dura, and even brain may occur. These lesions are considered invasive adenomas, and areas of hemorrhage and necrosis are not uncommon. Symptoms are mandated by mass effect and the functional status of the adenoma.
On histologic examination, pituitary adenomas consist of relatively uniform cells arranged in sheets or cords, with cytoplasm staining from acidophilic to basophilic depending on the secretory status. Their gelatinous consistency is attributable to relatively little connective stroma.
Treatment is typically surgical resection, with radiation reserved for residual tumor or poor surgical candidates. Endoscopic resection is becoming increasing common, and offers the advantages of improved magnification and visualization over standard microscopic resection. Elimination of the need for transnasal retractors also decreases secondary sinus-related morbidity in the post-operative period.
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