1/66. somatostatin receptor scintigraphy of a patient with a giant invasive prolactinoma.A 41-year-old with a giant prolactinoma underwent in-111 pentetreotide (octreotide) imaging showing very intense tracer uptake in the region of the anterior skull base. In contrast, there was no significant response to octreotide therapy. Prediction of clinical responsiveness to octreotide therapy in patients with pituitary adenomas may depend on the presence of somatostatin receptor subtype 5. Pentetreotide does not avidly bind to this receptor subtype and therefore, cannot be used clinically to predict therapeutic octreotide responsiveness in patients with large prolactinomas.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
2/66. Aggressive giant pituitary adenoma presenting as a nasopharyngeal mass: magnetic resonance imaging and pathologic findings.We report a giant pituitary adenoma with aggressive histologic features that prominently invaded the nasopharynx. magnetic resonance imaging (MRI) demonstrated a large heterogeneous nodular mass that was hypointense to isointense on T1-weighted images and mixed hypointense, isointense, and hyperintense on T2-weighted images. The mass measured 7.5 x 5 x 7 cm, extending from the nasopharynx posteriorly through the clivus, and superiorly through the paranasal sinuses, and sellar-suprasellar region. After contrast administration, heterogeneous nodular enhancement was noted. A nasopharyngeal neoplasm extending into the sella was suspected because voice change and nasal speech long preceded the patient's visual symptoms. A biopsy disclosed an aggressive, infiltrating, hemorrhagic tumor, which was diagnosed as a non-secreting pituitary macroadenoma. This report indicates that pituitary adenomas may grow invasively to tremendously large sizes resulting in their initial presentation as nasopharyngeal masses.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
3/66. Clinical and morphological features of undifferentiated monomorphous GH/TSH-secreting pituitary adenoma.A 41-year-old male presented with progressive visual defects, acromegaly and hyperthyroidism. After clinical evaluation a giant GH/TSH-secreting pituitary adenoma was diagnosed. Administration of the somatostatin analog octreotide at doses of 150 microg s.c. per day inhibited the secretion of both GH and TSH. A three-week treatment with octreotide prior to surgery led to slight visual improvement and CT scan showed some new necrotic areas within the tumor mass. Transcranial surgery was performed. By immunohistochemical analyses of the adenoma tissue GH, prolactin and beta-chorionic gonadotropin were detected; TSH was negative. Electron microscopy revealed an undifferentiated, monomorphous adenoma with morphological features of an acidophil stem cell adenoma such as the presence of misplaced exocytoses, fibrous bodies and mitochondrial gigantism. However, the tumor cells contained small secretory granules (up to 250 nm) accumulated along the cell membrane characteristic of thyrotrope cells. Furthermore, some adenoma cells were fusiform with long cytoplasmic processes resembling thyrotropes. Two months after the operation CT scan revealed a large residual tumor. serum GH and TSH levels had increased again and the TSH level was even higher than before the treatment. The patient died suddenly, most probably of lethal arrhythmia. Specimens of the adenoma tissue obtained at autopsy confirmed the previous findings with the exception of positive immunostaining for TSH which was found in less than 1% of the adenoma cells. This undifferentiated, monomorphous GH/TSH-secreting pituitary adenoma represents an entity that is unusual both in its ultrastructural features and clinical manifestations suggesting a cytogenesis from an early, undifferentiated stem cell.- - - - - - - - - - ranking = 0.2keywords = giant (Clic here for more details about this article) |
4/66. Giant insulinoma in a patient with multiple endocrine neoplasia-type I: a case report.We report a case of giant cystic insulinoma constituting part of multiple endocrine neoplasia (men) type I. A 29-year-old Japanese man presented with a history of recurrent hypoglycemic attacks. Endocrine examination showed hyperinsulinemia discordant with hypoglycemia, and a giant cystic insulinoma (11 x 10 cm) located in the pancreatic tail was detected radiologically. hyperprolactinemia due to pituitary adenoma and hyperparathyroidism due to parathyroid hyperplasia were also present. The insulinoma, prolactinoma and hyperplastic parathyroid gland were surgically removed. Fluorescent microsatellite analysis detected loss of heterozygosity (LOH) in chromosome 11q13 in dna samples from all resected tissues but not from white blood cells. This is a rare case of men type I because of the giant cystic insulinoma and the evidence of common LOH detected in all men type I tissues.- - - - - - - - - - ranking = 0.6keywords = giant (Clic here for more details about this article) |
5/66. pituitary apoplexy probably due to TRH and GnRH stimulation tests in a patient with acromegaly.pituitary apoplexy is the most serious and life-threatening complication of pituitary adenomas. Most of the cases occur spontaneously but it may occur also after a number of events such as the pituitary stimulation tests. We report a case of acromegaly due to a giant pituitary adenoma in which pituitary apoplexy developed 88 hours after TRH/GnRH stimulation test. The patient had severe headaches, nausea, vomiting, visual disturbance and mental alteration and the computed tomography (CT) scans revealed intratumoral and intraventricular bleeding. The pituitary mass was removed by transsphenoidal approach. The patient developed pneumonia and died on the 9th postoperative day. pituitary apoplexy was confirmed at surgery and on histological examination. Immunohistochemical staining was positive for GH and PRL. This case indicates that pituitary apoplexy may develop several days after TRH/GnRH stimulation test.- - - - - - - - - - ranking = 0.2keywords = giant (Clic here for more details about this article) |
6/66. Giant prolactinoma presented as unilateral exophthalmos in a prepubertal boy: response to cabergoline.We report the case of a giant prolactinoma in a 7-year-old boy, which was complicated by unilateral exophthalmos. The initial levels of prolactin (PRL) were about 80,000 microU/ml. Treatment with cabergoline (CAB) resulted in rapid normalization of serum PRL (6 weeks after initiation of treatment) and reduction of tumor size. In particular, magnetic resonance imaging (MRI), which was done 2.5 months after the patient was put on CAB, revealed tremendous improvement with a decrease in the size of the tumor which now showed no extrasellar extension. Subsequent MRI studies demonstrated further improvement. exophthalmos, anisocoria and visual fields improved. In summary, this patient represents the first report of the therapeutic use of CAB as the primary mode of treatment in a 7-year-old boy with infiltrative giant prolactinoma complicated by unilateral exophthalmos. It is a noninvasive treatment that can preserve and restore vision, as well as pituitary function, and is preferable to surgery or radiation in the treatment of prolactin-secreting macroadenoma in childhood and adolescence.- - - - - - - - - - ranking = 0.4keywords = giant (Clic here for more details about this article) |
7/66. A giant prolactinoma presenting with unilateral exophthalmos: effect of cabergoline and review of the literature.We report the case of a 45-year-old male presenting with unilateral exophthalmos due to a large tumoral mass invading the skull base. Ophthalmologic examination did not show any visual field defects. Imaging techniques demonstrated extension of a huge tumor (approx. 8x8x8 cm) into the right orbit and nasopharynx. Endocrine work-up revealed grossly elevated serum prolactin (PRL) levels (26,466 microg/l, nl. < 12), pointing to a large, invasive macroprolactinoma. Stimulation tests indicated associated partial adrenal and growth hormone deficiencies. Planned surgery was abandoned, and the patient was instead treated with the long-acting dopamine agonist, cabergoline. Over a period of one year, serum PRL dropped to 131 microg/l, while the tumor mass shrank to less than 50% of its original volume (with 3.5 mg/week of cabergoline). The exophthalmos disappeared, and the patient did not develop rhinorrhea or any other side effects from treatment with cabergoline. The efficacy was maintained throughout the second year (ultimate serum PRL 74 microg/l, and final size less than 10% of the original). With reference to this case, we review other macroprolactinomas reported in the recent literature for associated exophthalmos, grossly elevated serum PRL levels (> or = 15,000 microg/l), and/or "giant" size (> or = 4 cm in maximum diameter). We highlight the use of dopamine agonists in the treatment of prolactinomas with such unusual characteristics.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
8/66. Two familial giant pituitary adenomas associated with overweight: clinical, morphological and genetic features.OBJECTIVE: Pituitary adenomas are usually sporadic, although rare familial cases have been described. Here we report two first degree female cousins with giant pituitary adenoma and overweight. Both presented with secondary amenorrhoea, occasional headache and weight gain. MATERIALS AND methods: In both patients clinical, morphological and genetic studies were performed. Both patients underwent surgery and post-operative medical therapy with somatostatin analogues and dopamine agonist, followed by a conventional radiotherapy course. RESULTS: Clinical examination at presentation revealed an acromegaloid habitus only in the second patient. Basal and dynamic hormonal evaluation showed high serum GH and serum IGF-I values, higher in the second than in the first patient, and a mild hyperprolactinaemia only in the first patient. On optical and electron microscopy, both tumours were oncocytic adenomas, immunopositive for GH in the first patient and GH/prolactin in the second. The genetic analysis for germ-line mutations of the multiple endocrine neoplasia type 1 gene was negative. Two years after radiotherapy a remarkable shrinkage of both tumours was observed, whereas the overweight worsened in both patients, accompanied by high plasma leptin values. CONCLUSION: To our knowledge, this is the first report of familial pituitary adenomas including one case of a clinically silent GH-secreting adenoma. In addition, it provides further evidence that familial pituitary tumours can occur as a multiple endocrine neoplasia type 1 unrelated disease.- - - - - - - - - - ranking = 1keywords = giant (Clic here for more details about this article) |
9/66. Rapid re-expansion of a macroprolactinoma after early discontinuation of bromocriptine.Prolactin (PRL)-secreting pituitary adenomas are the most common functioning pituitary tumors. Medical treatment with dopamine agonists is the therapy of choice for macroprolactinomas (> or = 10 mm). Withdrawal of bromocriptine after weeks or months of uninterrupted therapy has been associated with rapid tumor re-expansion as evidenced by x-ray and CT scanning of the pituitary region. We report a patient with a giant macroprolactinoma who had a dramatic response to bromocriptine (tumor volume shrinkage of 53% within a month) but rapid re-expansion to its original dimensions one week after discontinuation of bromocriptine. To our knowledge, this is the first time that the rapid shrinkage/re-expansion of a macroprolactinoma has been documented with serial MRI scans.- - - - - - - - - - ranking = 0.2keywords = giant (Clic here for more details about this article) |
10/66. Giant intracranial granular-cell tumor arising from the abducens.We present a case of an adolescent with a giant intracranial granular-cell tumor, who presented with diplopia and worsening visual acuity. The tumor measured 8.2 cm at the maximum diameter and occupied the right middle cranial fossa, with intrasellar and suprasellar involvement. It was composed of solid nests of oval or polygonal eosinophilic cells with a focal pseudo-papillary configuration. Pituitary macroadenoma was suspected from examination of the intraoperative frozen section, but immunohistochemical and ultrastructural findings were consistent with granular-cell tumor, and they suggested the origin to be the peripheral nerve sheath. Considering that abducens palsy was the first clinical manifestation, the tumor was thought to arise from abducens. From histological findings (focal cellular spindling, mitotic activity and a relatively high Ki-67 labeling index [10.1%]) and according to Fanburg-Smith's criteria, the tumor was suspected to have low-grade malignant potential. Granular-cell tumor should be included in the differential diagnosis of parasellar tumors, even in young patients or patients with large lesions. Both immunohistochemical and electron microscopic studies are essential for diagnosis.- - - - - - - - - - ranking = 0.2keywords = giant (Clic here for more details about this article) |
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