Molecular Profiling of a Rare Rosette-Forming Glioneuronal Tumor Arising in the Spinal Cord.

Rosette-forming glioneuronal tumor (RGNT) of the IV ventricle is a rare and recently recognized brain tumor entity. It is histologically composed by two distinct features: a glial component, resembling pilocytic astrocytoma, and a component forming neurocytic rosettes and/or perivascular rosettes. Herein, we describe a 33-year-old man with RGNT arising in the spinal cord.

Pituicytoma with gelsolin amyloid deposition.

Pituicytoma is a rare low-grade (WHO grade I) sellar region glioma. Among sellar tumors, pituitary adenomas, mainly prolactinomas, may show amyloid deposits. Gelsolin is a ubiquitous calcium-dependent protein that regulates actin filament dynamics.

On pseudo-onion bulb intraneural proliferations of the non-major nerves of the oral mucosa.

Perineurial cells (PCs) participate in reactive and neoplastic processes, of the latter pure perineurial being intraneural (IP) and soft tissue perineuriomas with oral examples being reported in both. In our review of over 500 peripheral nerve sheath tumors including granular cell tumor, we identified a single ostensible case of IP occurring on the tongue of a 45-year-old African-American male that was characterized by classic perineurial pseudo-onion bulbs (PsOb), proliferating PCs among these PsOb, sclerosis apparently due to long term duration and a plexiform pattern. We have also encountered 37 examples of apparently reactive, hyperplastic or traumatic, PsOb intraneural pseudoperineuriomatous proliferation (IPP) simulating microscopically some of the properties of IP.

Neurocristic cutaneous hamartoma of the scalp.

Neurocristic cutaneous hamartoma of the scalp, a rare entity, may be either congenital or acquired. The former must be distinguished from other forms of congenital nodular and plaque-like lesions such as giant congenital nevi, common and cellular blue nevi, and melanoma. We describe the clinicopathologic features of an example occurring in a 2-month-old girl presenting with a large parietooccipital swelling.

Pituitary stalk lesions: the Mayo Clinic experience.

Context: Pituitary stalk lesions have various etiologies, often not clinically apparent. Pathological samples from these lesions are rarely obtained, because of the critical location and function of the hypophyseal stalk.

Objectives: The purpose of this study was to characterize the etiological spectrum of pituitary stalk lesions seen at Mayo Clinic Rochester over 20 years and to determine whether specific magnetic resonance imaging (MRI) characteristics could provide clinician guidance with regard to the etiology of infundibular lesions.

Immunohistochemical expression of PTTG in brain tumors.

Background: Pituitary tumor-transforming gene (PTTG1) has been implicated in several oncogenic processes. The aim of this study was to determine PTTG expression in brain tumors.

Materials And Methods: We investigated 88 benign and malignant brain tumors.

Biomarkers of pituitary neoplasms.

In a wide spectrum of tumors, cell proliferation, vascularity, apoptosis, cell adhesion, and cell-cycle progression may indicate tumor progression. In this review article, the literature regarding apoptotic markers and p53, as well as cyclooxygenase-2, galectin-3, and pituitary tumor-transforming factor, proliferative markers, angiogenesis, including vascular endothelial growth factor and its receptor, pituitary tumor-transforming gene, microarrays, stem cells, and microenvironment and tumor heterogeneity are presented. Only a particular group of selected biomarkers show promise in differentiating pituitary tumors which will behave in an aggressive manner.

ACTH-secreting Crooke cell carcinoma of the pituitary.

Purpose: While pituitary adenomas are common, pituitary carcinomas are rare. It is unclear whether pituitary carcinomas arise de novo or evolve from adenomas.

Methods: We studied the clinical characteristics and tissue samples from eight pituitary surgeries and the autopsy from a patient with pituitary carcinoma.

Hemangioblastoma of spinal nerve: a report of six cases.

Aims: Hemangioblastomas may arise sporadically or in the setting of Von Hippel-Lindau (VHL) disease. In either instance, it rarely occurs outside the central nervous system. By analysis of a large case series, we sought to further characterize the clinical, radiologic and pathologic features of hemangioblastomas involving nerve root.

Malignant peripheral nerve sheath tumor: the utility of fascicular biopsy and teased fiber studies.

We present the case of a 67-year-old man with a malignant peripheral nerve sheath tumor (MPNST) affecting the brachial plexus. He presented with progressive right upper extremity paresthesias, numbness, weakness, and severe pain. Nerve conduction studies/electromyography demonstrated a right lower and middle trunk predominant brachial plexopathy.

Atypical pituitary adenoma with neurocytic transformation.

Here, we report an example of an atypical prolactin-producing pituitary adenoma showing clear morphologic and immunohistochemical evidence of neurocytic transformation. Its features support the concept that neoplastic neuroendocrine cells, in this case adenohypophyseal cells, are capable of neuronal differentiation and broaden the morphologic spectrum of such rare tumors. Our findings have implications with respect to the nosology of neuronal tumors of the adenohypophysis.

Meningiomas in pregnancy: a clinicopathologic study of 17 cases.

Background: Dramatic growth of meningiomas is occasionally encountered during pregnancy. While cell proliferation is often assumed, hemodynamic changes have also been touted as a cause.

Objective: We identified 17 meningiomas resected during pregnancy or within 3 weeks post-partum and characterized them to determine the cause of occasional rapid growth in pregnancy.

Malignant perineurioma (malignant peripheral nerve sheath tumor with perineural differentiation).

The great majority of malignant peripheral nerve sheath tumors (MPNST) exhibit Schwannian differentiation. In recent years, a subset of perineurial MPNST (malignant perineurioma) has been identified based on their histologic, immunohistochemical and ultrastructural features. Immunopositivity for epithelial membrane antigen (EMA), glut-1 and claudin-1, is characteristic.

Transdifferentiation of pituitary thyrotrophs to lactothyrotrophs in primary hypothyroidism: case report.

Primary hypothyroidism causes adenohypophysial hyperplasia via stimulation by hypothalamic thyrotropin-releasing hormone (TRH). The effect was long thought to simply result in thyroid-stimulating hormone (TSH) and prolactin (PRL) cell hyperplasia, an increase in TSH and PRL blood levels with resultant pituitary enlargement, often mimicking adenoma. Recently, it was shown that transformation of growth hormone (GH) cells into TSH cells takes place in both clinical and experimental primary hypothyroidism.

Sellar meningiomas: an endocrinologic perspective.

To review the clinical manifestations and outcomes of those with sellar meningiomas treated surgically at Mayo Clinic between 1975 and 2003. This is a retrospective chart and pathology review of 17 patients with a diagnosis of purely or largely intrasellar meningiomas treated surgically at our institution. Data in regards to presentation, endocrine hormonal status, surgical approach, pathology findings, outcome and adjunctive treatment were abstracted from the medical records.

Melanoma of the sellar region mimicking pituitary adenoma.

We report here the case of an 82-year-old woman who presented with visual disturbance. MRI demonstrated a sellar mass. The diagnosis of pituitary adenoma was made.

Temozolomide in aggressive pituitary adenomas and carcinomas.

Temozolomide is an alkylating agent used in the treatment of gliomas and, more recently, aggressive pituitary adenomas and carcinomas. Temozolomide methylates DNA and, thereby, has antitumor effects. O6-methylguanine-DNA methyltransferase, a DNA repair enzyme, removes the alkylating adducts that are induced by temozolomide, thereby counteracting its effects.

Pituitary tumors in patients with MEN1 syndrome.

We briefly review the characteristics of pituitary tumors associated with multiple endocrine neoplasia type 1. Multiple endocrine neoplasia type 1 is an autosomal-dominant disorder most commonly characterized by tumors of the pituitary, parathyroid, endocrine-gastrointestinal tract, and pancreas. A MEDLINE search for all available publications regarding multiple endocrine neoplasia type 1 and pituitary adenomas was undertaken.

Glomus tumor of digital nerve: case report.

Glomus tumors consist of modified perivascular, smooth muscle involved in thermoregulatory activity of digital blood flow. Digits, especially in the subungual region, are often affected. These tumors only rarely arise in peripheral nerves; digital nerve involvement is exceptional.

Inhibin-A immunoreactivity in nervous system lesions.

To evaluate inhibin-A immunoreactivity and its utility in the differential diagnosis of nervous system neoplasms and non-neoplastic lesions. An immunohistochemical study of 252 central and peripheral nervous system tumors and 40 non-neoplastic lesions was undertaken. Brain lesions included the basic spectrum of astrocytic, oligodendroglial, and ependymal neoplasms, as well as glioneuronal, pineal parenchymal, choroid plexus, and embryonal.

Bronchial carcinoid tumors metastatic to the sella turcica and review of the literature.

We review here the literature on neuroendocrine neoplasms metastatic to the pituitary and present an example of the disease. Metastasis of bronchial carcinoid tumors to the sellar region are rare. Herein, we describe the case of a 63-year-old woman who presented with constant cough and headaches.