methimazole and Pituitary-Neoplasms

Hypothyroidism is relatively rare etiology of serositis with effusion, but massive pleural effusion is very unusual. This is a report of massive pleural effusion in patient taking methimazole after surgical resection of thyroid-stimulating hormone (TSH)-producing pituitary adenoma (TSHoma). The patient was clinically and biochemically hypothyroid and responded well to discontinuation of methimazole and thyroid hormone replacement therapy. When assessing patients with pleural effusion, we should not rely on laboratory test results alone, as a detailed medical history and thorough physical examination could be more useful.

Topics: Antithyroid Agents; Humans; Hypothyroidism; Male; Methimazole; Middle Aged; Pericardial Effusion; Pituitary Neoplasms; Pleural Effusion; Thyrotropin

Thyrotropin-secreting adenoma (TSHoma) is rare. Even though the thyrotoxicosis is mild in patients with TSHoma, it is still a rare cause of arrhythmia, ignore of mild disfunction of thyroid function of TSHoma can lead to the delayed diagnosis of pituitary tumor or leading to recurring of complications. Graves' disease is an auto-immue endocrinological disorder. Association of TSHoma and Graves's disease is extremely rare. Coexistence of these two diseases made the diagnosis and treatment complicated.. This patient was a 55-year-old man who had been referred to the department of endocrinology and metabolism of the West China Hospital due to recurrent atrial fibrillation (AF) and thyroxicosis.. Examinations revealed pituitary thyrotropin-secreting macroadenoma with Graves' disease.. We conducted transsphenoidal surgery. Thyrozol was used to treat the recurrence of Graves' disease after pituitary surgery.. The TSHoma was successfully cured, and recurrent Graves' disease was controlled very well.. The association of TSHoma and Graves' disease is extremely rare. Even though the clinical features of thyrotoxicosis are milder in patients with TSHoma, thyroid function tests are still important clinical assessment of patients with AF, which is an arrhythmia associated with hyperthyroidism. TSHoma is a rare cause of thyrotoxicosis; however, ignoring of the mild disfunction caused by TSHoma can lead to the delayed diagnosis of pituitary tumors or to recurring of complications of TSHoma.

Topics: Antithyroid Agents; Atrial Fibrillation; Catheter Ablation; China; Graves Disease; Humans; Magnetic Resonance Imaging; Male; Methimazole; Middle Aged; Neurosurgical Procedures; Pituitary Gland; Pituitary Neoplasms; Recurrence; Thyrotoxicosis; Thyrotropin

While TSH-producing adenoma (TSHoma) is rare, the diagnosis is often delayed because the clinical features are heterogeneous. The patient was a 69-year-old woman who had been referred to the Yachiyo Medical Center in August 2008, because of dyspnea, loss of appetite, weight loss of 10 kg, and diarrhea that lasted 4 years. We diagnosed this patient with pituitary TSH-producing macroadenoma. Thyroid hormone concentration was increasing although the serum TSH level was within a normal range after trans-sphenoidal surgery. We considered that because of enlargement of the thyroid gland due to long-term stimulation by TSH, a low concentration of TSH could stimulate the thyroid gland to produce excess T3 or T4. The somatostatin analogue, octreotide was used to control the TSHoma and serum TSH concentration but not thyroid hormone. The octreotide in combination with thiamazole treatment for 14 months controlled thyroid hormone concentration and decreased the thyroid mass, and ultimately, the thiamazole could be stopped. To date, the use of combination therapy of octreotide with thiamazole in patients with remaining TSH-producing adenoma without Basedow's disease is rare, and we suggest that this treatment is one of the therapeutic means to treat recurrence of TSH-producing adenoma after surgery with progressive complications or large thyroid gland.

Topics: Adenoma; Aged; Drug Therapy, Combination; Female; Humans; Methimazole; Octreotide; Pituitary Neoplasms; Thyrotropin

A 52-year-old Japanese male complained of palpitations and excessive sweating. He showed evidence of hyperthyroidism, but without suppression of the serum thyroid-stimulating hormone (TSH). On admission, the serum level of the alpha-subunit of TSH was elevated, but tests for thyroid autoantibodies were negative. The TSH response to thyrotropin-releasing hormone (TRH) was blunted. Imaging studies revealed a pituitary tumor 2 cm in diameter. Administration of methimazole lowered the serum levels of thyroid hormones, and elevated the serum level of TSH. These findings led to the diagnosis of a thyrotropin-secreting pituitary tumor. Immunohistochemical analysis and electron microscopic findings verified the diagnosis.

Topics: Antithyroid Agents; Humans; Magnetic Resonance Imaging; Male; Methimazole; Middle Aged; Neoplasms, Hormone-Dependent; Pituitary Neoplasms; Radiography; Thyrotropin

The purpose of this study was to evaluate the contribution of endogenous GH-releasing hormone (GHRH) to exogenous GH-releasing hexapeptide (GHRP-6) activity, and to determine whether TRH or GnRH are endogenous analogs of GHRP-6. The activity of GHRP-6, a synthetic GH secretagogue, was significantly attenuated in rats administered GHRH antiserum or alpha-methyl-rho-tyrosine to reduce endogenous GHRH concentrations, and also in rats administered 5-50 micrograms/kg of [N-Ac-Tyr1,D-Arg2]-GRF 1-29 amide to block pituitary GHRH receptors. However, GHRP-6 activity was potentiated in rats administered 150 micrograms/kg [N-Ac-Tyr1,D-Arg2]-GRF 1-29 amide, presumably due to partial agonist activity of the GHRH receptor antagonist at the higher dose. These data show that endogenous GHRH contributes to full expression of exogenous GHRP-6 activity in vivo. Like TRH, a subthreshold dose of GHRP-6 was significantly more effective in hypothyroid rats than in euthyroid rats. However, suprathreshold doses of GHRP-6 were less effective in hypothyroid rats. Unlike TRH, GHRP-6 had no effect on GH and prolactin release from GH3 cells, and TRH and GnRH were poor competitors for 3H-GHRP-6 binding sites on pituitary membranes. A GnRH receptor antagonist did not block GHRP-6 activity in vivo, and GnRH administered alone or in combination with GHRP-6, did not stimulate GH release. The results of this study suggest that synergy between GHRH and GHRP-6 seen in pharmacological studies is physiologically relevant, and that TRH and GnRH are not endogenous analogs of GHRP-6.

Topics: alpha-Methyltyrosine; Animals; Cell Line; Dose-Response Relationship, Drug; Female; Growth Hormone; Growth Hormone-Releasing Hormone; Hormones; Hypothyroidism; Immune Sera; Methimazole; Methyltyrosines; Oligopeptides; Pituitary Neoplasms; Rats; Rats, Inbred Strains; Receptors, Neuropeptide; Receptors, Neurotransmitter; Receptors, Pituitary Hormone-Regulating Hormone; Thyroid Gland; Thyroxine; Triiodothyronine

Seven patients with hyperthyroidism due to a TSH-secreting pituitary macroadenoma have been observed of a total of 800 patients with pituitary tumors over a period of 15 yr. Serum TSH levels varied between 1.1-36.3 mU/L. The serum alpha-subunit level was low in 1 case, while in 4 other cases the concentration was elevated and varied between 3.7-7.8 micrograms/L. Serum TSH beta levels were normal in the 4 cases in which it was determined. Serum GH or PRL levels were elevated in 5 cases. In 1 patient the cosecretion of TSH, GH, and PRL was confirmed by immunocytochemical examination. Serum TSH and alpha-subunit responses to TRH, GnRH, CRF, GRF, dexamethasone, methimazole, T3, and bromocriptine administration were variable when studied. Serum TSH and alpha-subunit circadian rhythms were absent in 1 case and inverted in another. A serum alpha-subunit pulsatility without TSH pulses was observed in 1 patient. Five patients underwent transsphenoidal adenomectomy. Three of 4 patients operated on in our center were cured, but a recurrence of the adenoma was found in 1 of them after 5 yr. The fifth patient was not cured. Treatment with octreotide in 3 patients resulted in normalization of serum TSH, GH, and thyroid hormones levels. Cosecretion of PRL in 1 case and alpha-subunit in 2 cases was also inhibited. Partial tachyphylaxis occurred in 1 patient. In summary, heterogeneity in clinical presentation, hormonal expression, and therapeutic response appears to characterize these TSH-secreting adenomas.

Topics: Adenoma; Adolescent; Adult; Aged; Aged, 80 and over; Bromocriptine; Circadian Rhythm; Female; Glycoprotein Hormones, alpha Subunit; Growth Hormone; Humans; Hyperthyroidism; Male; Methimazole; Middle Aged; Octreotide; Pituitary Neoplasms; Prolactin; Thyrotropin; Thyrotropin-Releasing Hormone

A case is reported of neoplastic TSH hypersecretion in a 62-year-old man with severe hyperthyroidism and cardiovascular disease. He had been known to be hyperthyroid for 14 yr, and had been treated by thyreostatic drugs and subtotal thyroidectomy without satisfactory results. When he was referred to our Center, he was frankly hyperthyroid with both TSH (14 microU/ml) and thyroid hormone serum levels (TT4 24 micrograms/dl, TT3 370 ng/dl, FT41 7.9) above the normal range. alpha-subunit serum level was markedly increased (7.2 ng/ml), while beta-subunit was only 0.3 ng/ml. Skull X-ray showed an enlarged sella turcica with destruction of the dorsum and an intrasellar tumor was visualized on conventional and computer tomography. TSH response was absent after TRH and domperidone, while TSH serum levels decreased by 25% after bromocriptine. Methimazole therapy temporarily decreased serum thyroid hormones to normal levels, while TSH levels rose to 34 microU/ml, thus indicating that pituitary-thyroid feed-back was maintained at a higher set point. Surgical attempt failed because of cardiac problems during anesthesia. Radiotherapy plus methimazole was begun and TSH serum levels first increased markedly, up to 140 microU/ml, and then progressively decreased without reaching normal values. After methimazole withdrawal hyperthyroidism recurred.

Topics: Bromocriptine; Cardiovascular Diseases; Humans; Hyperthyroidism; Male; Methimazole; Middle Aged; Pituitary Gland; Pituitary Neoplasms; Thyrotropin; Thyroxine; Triiodothyronine

Subtotal tumour removal had been performed in a 34-year-old female patient for an extensive intra- and suprasellar expansive process. The considerably increased prolactin level did not decrease postoperatively, but normalised only after a three months bromocriptine treatment. The primary hyperthyroidism has been recovering after administering methimazolum. In a second case was reported on a 65-year-old female patient, suffering from rachitic dwarfism, stenosis of the aortic valve and tumour of the hypophysis, causing acromegaly, whose diabetes mellitus of contrainsular type could have been hardly balanced with insulin of a 128-unit-dose daily, and whose hyperthyroidism was due to an autonomous adenoma of the thyroid gland, first I-131 treatment was administered and she got into an euthyroid state. Six weeks following the removal of the acidophilic adenoma of the hypophysis administration of insulin could have been ceased, and the results of her growth hormone became normal. The clinical picture partly corresponds with Troell-Junet's syndrome.

Topics: Acromegaly; Adenoma; Adenoma, Acidophil; Adenoma, Chromophobe; Adult; Aged; Diabetes Complications; Female; Humans; Hyperthyroidism; Methimazole; Pituitary Neoplasms; Thyroid Neoplasms

Two patients with overproduction of thyroid-stimulating hormone (TSH) are described. The first patient, a 25-year-old man with recurrent hyperthyroidism, had a pituitary adenoma and highly elevated levels of TSH. While the patient was receiving 0.3 mg of thyroid daily, and basal TSH level was 161 microM/ml. Despite an increase in the thyroid hormone therapy, serum TSH levels remained elevated. The administration of thyrotropin-releasing hormone (TRH) or dexamethasone resulted in no changes in TSH level. The second patient was an 18-year-old man who had inappropriately elevated levels of TSH 3 months after radioiodine therapy for hyperthyroidism. A gradual increase in thyroid hormone replacement therapy decreased the serum TSH levels from 250 to 14.8 microM/ml. The administration of TRH led to huge increases of TSH. Dexamethasone inhibited basal TSH but not TRH-stimulated TSH levels. The overproduction of TSH was attributed to autonomous, neoplastic secretion in the first case and to partial, selective pituitary thyrotroph resistance to thyroid hormone in the second.

Topics: Adenoma; Adolescent; Adult; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Methimazole; Pituitary Neoplasms; Sphenoid Sinus; Thyrotropin; Thyroxine; Triiodothyronine

Further examination of rat pituitary cell line GH3/C14 showed that at least the physiologic concentration of L-thyroxine was required for estrogen-dependent growth in vivo. Two L-thyroxine synthesis inhibitors, 6-n-propyl-2-thiouracil (propylthiouracil) and 1-methylimidazole-2-thiol (methimazole), were administered concurrently with estrogen to GH3/C14-inoculated hosts. Propylthiouracil administration to estrogen-treated males, intact females, and estrogen-treated ovariectomized females inhibited tumor formation by 93, greater than 95, and 68%, respectively, as compared to tumor formation in controls not treated with propylthiouracil. Methimazole treatment of estrogen-primed males and intact females inhibited tumor formation by 78 and 95%, respectively. Concentrations of total L-thyroxine and free L-thyroixine in sera from normal and inhibitor-treated hosts were depressed 70-80% by propylthiouracil and 60-70% by methimazole. Administration of either drug caused greater inhibition of tumor growth than of total body weight gain. In addition, the administration of a combination of L-thyroxine and L-triiodothyronine to male rats promoted tumor formation even in the absence of exogenous estrogen.

Topics: Animals; Body Weight; Castration; Cell Division; Cell Line; Estrogens; Female; Male; Methimazole; Neoplasms, Experimental; Ovary; Pituitary Neoplasms; Propylthiouracil; Rats; Rats, Inbred WF; Thyroxine

Topics: 17-Hydroxycorticosteroids; Adenoma, Chromophobe; Adult; Biological Assay; Blood Pressure; Cerebral Angiography; Gonadotropins; Hemangioma; Humans; Hyperthyroidism; Insulin; Iodine; Iodine Isotopes; Lysine; Male; Methimazole; Middle Aged; Pituitary Neoplasms; Radioimmunoassay; Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine; Vasopressins

Topics: Adenoma, Chromophobe; Craniotomy; Hemianopsia; Humans; Hyperthyroidism; Iodides; Male; Methimazole; Middle Aged; Pituitary Neoplasms; Radioimmunoassay; Thyrotropin; Visual Fields