Pituitary stalk meningioma: case report

Meningioma associated with intraosseous lipoma

Intraosseous lipomas of the skull are quite rare and only eight cases have been reported. The lipoma in our case was different from that in others in that it showed remarkable proliferation of collagen tissue. This is the first report of meningioma occurring after removal of an intraosseous lipoma of the skull. This report concerns a rare case of a 32-year-old female who developed a huge convexity meningioma 11 years after successful removal of intraosseous lipoma of the left frontoparietal bone. The meningioma originated from the convexity where the lipoma had been, and extended intracranially to the sphenoid ridge. The patient underwent surgical exploration showing that the meningioma had invaded the frontoparietal convexity bone and was firmly attached to the coronal suture with a large dural defect. This rare coincidence suggests that proliferative changes of the intraosseous lipoma and meningeal neoplasm may be the result of the same, as yet unknown, mechanism.

'Spindle cell oncocytoma' of the adenohypophysis: a tumor of folliculostellate cells?

We describe five primary tumors of the adenohypophysis featuring mitochondrion-rich spindle cells. The patient ages ranged from 53 to 71 years (mean 61.6 years); two were female. All presented with panhypopituitarism. Two also had visual field defect. On neuroimaging all tumors showed suprasellar extension and were indistinguishable from pituitary adenoma. None showed imaging or operative evidence of dural involvement. All were gross totally removed: four by transsphenoidal surgery and one by frontal craniotomy. Follow-up ranged from 2 to 68 months (mean 35.4 months). No recurrences were noted. The clinical workup was noncontributory in all but two patients: one (case no. 4) with an oncocytic thyroid adenoma and another (case no. 5) with squamous carcinoma of both the uterine cervix and of vocal cord. Histologically, the five tumors were composed mainly of fascicles of spindle cells with eosinophilic, granular cytoplasm. Mitoses were rare and necrosis was absent. Neoplastic cells were immunoreactive for vimentin, epithelial membrane antigen, S-100 protein, and galectin-3. Stains for pituitary hormones, synaptophysin, chromogranin, glial fibrillary acidic protein, cytokeratin CAM5.2, smooth muscle actin, CD34, and CD68 were negative. No thyroglobulin immunoreactivity was noted in the tumor of case no. 4. Ultrastructurally, the neoplastic cells contained numerous mitochondria with lamellar cristae. The neoplastic cells were linked by intermediate junctions and desmosomes. No secretory granules were noted. The histologic, immunohistochemical, and fine structural features of these tumors were unlike those of pituitary adenoma or any other primary sellar tumor. A derivation from adenohypophyseal folliculostellate cells is suggested.

Meningioma of the pituitary stalk without dural attachment: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Tumors in the suprasellar region such as adenomas of the pituitary gland, craniopharyngiomas, nonneoplastic cystic lesions (especially Rathke's cleft cysts), and meningiomas are frequently encountered in neurosurgical practice. Meningiomas originate from the arachnoid layer connected to the dura of the anterior or posterior clinoidal process, or the tuberculum, dorsum, or diaphragma sellae. Tumors originating from the pituitary stalk are rare. Such lesions may include germinomas, astrocytomas, histiocytosis X, hamartomas, and sarcoidosis. We report a patient with a suprasellar meningioma originating from the pituitary stalk with no connection to the adjacent dura.

CLINICAL PRESENTATION

A 50-year-old man was assessed for impotence and loss of libido. Physical examination revealed no abnormalities. Endocrinological investigations disclosed nearly complete hypopituitarism, and magnetic resonance imaging revealed a suprasellar homogeneously enhancing tumor.

INTERVENTION

Complete surgical resection was performed in an endoscope-assisted right-sided supraorbital craniotomy. The tumor originated from the pituitary stalk with no connection to the surrounding dura. The histopathological diagnosis was meningioma.

CONCLUSION

Although meningiomas frequently occur in the suprasellar region, this patient with a suprasellar meningioma is unique because the tumor originated from the pituitary stalk with no connection to the surrounding dura. The absence of dural attachment has been described in 43 extracerebral meningiomas, but a suprasellar location has been reported only once previously. Recognition of this phenomenon is important, because meningiomas require a different therapeutic strategy than most other tumors of the pituitary stalk.

The human hypothalamo-neurohypophysial system in health and disease

The present paper reviews the changes observed in the human supraoptic (SON) and paraventricular (PVN) nuclei, and their projections to the neurohypophysis, median eminence and to other brain areas in health and disease.

Differential diagnosis of sellar masses

The differential diagnosis of nonpituitary sellar masses is broad; differentiating among potential etiologies may not always be straightforward because many of these lesions, tumorous and nontumorous, may mimic the clinical, endocrinologic, and radiologic presentations of pituitary adenomas. This article provides an overview of the clinical and radiographic characteristics of both pituitary tumors and the nonpituitary lesions found in the sellar/parasellar region and discusses, in detail, the specific nonpituitary origins of the sellar masses.