Tumors of the Sellar Region Mimicking Pituitary Adenomas

Abstract

In the sellar region most tumors of our collection (n = 1937) are pituitary adenomas, followed by craniopharyngiomas, chordomas and meningiomas. Difficulties in morphological differential diagnosis by light microscopy may occur in meningiomas, plasmacytomas, chordomas and germinomas. In these cases, immunohistological investigations and sometimes even electron microscopy are helpful in solving the problems. Meningiomas can sometimes resemble pituitary adenomas. Of diagnostic value in these cases is the expression of vimentin and S-100-protein in the meningioma cells. Plasmacytomas may also mimic pituitary adenomas. In these cases, the positive reaction with antibodies against LCA and immunoglobulins or against kappa-light-chains and lambda-light-chains leads to the diagnosis. Chordomas, too, can sometimes be hardly distinguished from pituitary adenomas. In these cases, the expression of S-100-protein, vimentin and CEA by the chordoma cells and the typical electron microscopic features of chordomas are helpful for the differential diagnosis. Germinomas may sometimes be indistinguishable from lymphocytic hypophysitis. Of diagnostic importance are here the expression of HCG and placental alkaline phosphatase by germinoma cells. In the above mentioned cases, it is also important to perform immunohistochemical examinations for pituitary hormones including alpha-subunit. All these tumors do not express these hormones.

Intrasellar plasmacytoma: An illustrative case and literature review

“…In an impressive series of 1,973 patients with sellar masses, 47 were misdiagnosed as adenomas pre-operatively. 7 A review in 2007 collated all reported cases of sellar mass caused by plasmacytomas or disseminated MM to that date. 2 We add to these cases already reported in the literature, with our patient, to review a total of 26 cases (Tables 1-3).…”

Collision Tumors of the Sella: Craniopharyngioma and Silent Pituitary Adenoma Subtype 3: Case Report

“…Most are benign, solitary, slow-growing lesions, either producing endocrine symptoms via hormonal excess or being non-functional. Pituitary adenomas comprise more than 90% of sellar masses [1] and 10% to 15% of all intracranial neoplasm [2]. Most present during adulthood.…”

Primary sellar lymphoma: intravascular large B-cell lymphoma diagnosed as a double cancer and improved with chemotherapy, and literature review of primary parasellar lymphoma

“…Pituitary adenoma is the most common sellar tumor: it accounts for more than 90% of all sellar tumors [19]. Other causes of sellar tumors are craniopharyngioma, chordomas, meningioma, etc.…”

“…Other causes of sellar tumors are craniopharyngioma, chordomas, meningioma, etc. [19]. Primary pituitary lymphoma is extremely rare; out of 1120 patients who underwent transsphenoidal surgery for sellar masses, only 1 case (0.1%) was reported to have primary pituitary lymphoma [20].…”