Medical Management of Thyrotropin-Secreting Pituitary Adenomas

Thyrotropin-secreting pituitary tumors (TSH-omas) are a rare cause of hyperthyroidism and account for less than 1% of all pituitary adenomas. It is however noteworthy that the number of reported cases tripled in the last years as a consequence of the routine use of ultrasensitive immunometric assays for measuring TSH levels. Contrary to previous RIAs, ultrasensitive TSH assays allow a clear distinction between patients with suppressed and those with non-suppressed circulating TSH concentrations, i.e. between patients with primary hyperthyroidism (Graves' disease or toxic nodular goiter) and those with central hyperthyroidism (TSH-oma or pituitary resistance to thyroid hormone action). Failure to recognize the presence of a TSH-oma may result in dramatic consequences, such as improper thyroid ablation that may cause the pituitary tumor volume to further expand. The medical treatment of TSH-omas mainly rests on the administration of somatostatin analogs, such as octreotide and lanreotide. In fact, administration of dopamine agonists failed to persistently block TSH secretion in almost all patients and caused tumor shrinkage only in those with combined hypersecretion of TSH and PRL. On the contrary, somatostatin analogs were effective in reducing TSH and -subunit secretion in more than 90% of cases with consequent normalization of FT4 and FT3 levels and restoration of the euthyroid state in the majority of them. In about one third of patients, a clear shrinkage of tumor mass and vision improvement could be demonstrated. Tachyphylaxis, cholelithiasis and carbohydrate intolerance occurred in a minority of treated patients. Whether somatostatin analog treatment may be an alternative to surgery and/or irradiation in patients with TSH-oma remains to be established. Nonetheless, the long-acting somatostatin preparations represent a useful tool for long-term treatment of such a rare pituitary tumors.     

Efficacy of the long-acting octreotide formulation (octreotide-LAR) in patients with thyrotropin-secreting pituitary adenomas

The presence of somatostatin receptors on TSH-secreting pituitary adenomas allows treatment of central hyperthyroidism with somatostatin analogs. Six women and 5 men (mean +/- SEM age, 43 +/- 3 yr) presented TSH-secreting pituitary adenomas (micro, n = 2; macro, n = 9). Seven patients had previously been treated with partial surgical removal (n = 6) and/or external radiation (n = 4) of their adenoma at least 1 yr before the study, whereas 4 patients had not been treated before somatostatin analog therapy. TSH, free T(4), and free T(3) levels were in the normal range during treatment with sc injections (n = 9) or continuous infusion (n = 2) of octreotide (280 +/- 25 microg/day). Mean thyroid hormone levels increased (P < 0.01) after the washout period (34 +/- 6 days). The patients received monthly im injections of 20 mg Octreotide-LAR. In patients with an elevated free T(4) level after 3 months (n = 1) the Octreotide-LAR dose was increased to 30 mg. After 3 months of Octreotide-LAR treatment, TSH, free T(4)/T(3), and alpha-subunit levels decreased, and 10 patients were euthyroid with normal free T(4) levels. These results remained at the same level over the next 3 months. There were no statistically significant differences in the TSH and free T(4) responses to sc octreotide or im Octreotide-LAR between previously untreated patients and patients who had undergone surgical resection and/or pituitary radiation before somatostatin analog treatment. During Octreotide-LAR treatment, minor digestive problems or moderate discomfort at the injection site, lasting less than 48 h, were reported in 6 and 5 patients, respectively. Gallbladder echographies did not reveal new gallstones during Octreotide-LAR treatment. In conclusion, this study shows that monthly im Octreotide-LAR is as effective as daily sc octreotide in controlling hyperthyroidism in patients with TSH-secreting pituitary adenomas, in both previously untreated patients and patients treated with surgery and/or pituitary radiotherapy. Octreotide-LAR is well tolerated, except for minor digestive problems or mild pain at the injection site. Therefore, Octreotide-LAR appears to be a useful therapeutic tool to facilitate medical treatment of TSH-secreting pituitary adenomas in patients who need long-term somatostatin analog therapy.     

Thyrotropin-secreting tumor “TSH-PitNET”: From diagnosis to treatment

Thyrotropic adenomas (TSH-PitNET) are the rarest pituitary tumours. Most TSH-PitNETs are secreting adenoma, with a biological picture of inappropriate TSH secretion (moderately elevated TSH, elevated FT3 and FT4). Patients present most often clinical hyperthyroidism, but with more moderate symptoms than in peripheral hyperthyroidism. Biological diagnosis is not always easy. The main differential diagnoses are interfering antibody assay interactions, dysalbuminemia and thyroid hormone resistance syndrome. Misdiagnosis is common. However, the diagnosis is easier when macroadenomas are involved (80% of cases), with symptoms of optic chiasm compression, headache and signs of hypopituitarism. Treatment is initially based on surgery. In case of failure, somatostatin analogues are very effective in controlling tumor volume and secretion, although there is a risk of thyroid insufficiency, which is usually transient.     

Treatment of hyperthyroidism due to inappropriate secretion of thyrotropin with the somatostatin analog SMS 201-995

The management of hyperthyroidism due to inappropriate secretion of TSH (IST) includes agents that selectively suppress TSH hypersecretion both in patients with TSH-secreting tumor [neoplastic IST (nIST)] in whom pituitary surgery was unsuccessful and in those with selective pituitary resistance to thyroid hormone action [nonneoplastic IST (nnIST)]. Among such agents, somatostatin administration has proven to be effective in blocking TSH hypersecretion, but its short plasma half-life prevented its use in long term therapeutic trials. The recent availability of a potent and long-acting analog of somatostatin (SMS 201-995, Sandostatin) prompted us to study its effects on serum TSH, alpha-subunit, and free thyroid hormone (FT4 and FT3) concentrations in five patients with nIST and three patients with nnIST. During short term SMS 201-995 administration (100 micrograms, sc, three times daily for 5 days) both serum TSH and alpha-subunit levels decreased in all patients with nIST (mean decrements, -86% and -85%, respectively), with concomitant normalization of serum FT4 and FT3 concentrations. In the three patients with nnIST, this treatment lowered serum TSH levels less well (mean decrement, -47%), although serum FT4 and FT3 levels normalized in one patient. Chronic SMS 201-995 (100 micrograms, sc, every 12 h for 1-7 months) treatment in four hyperthyroid patients (two with nIST and two with nnIST) resulted in a steady euthyroid state in both patients with nIST, with restoration of normal visual fields in one patient. In contrast, in both patients with nnIST, escape occurred after 2 weeks of therapy. We conclude that SMS 201-995 administration is effective treatment for patients with nIST, able to suppress TSH hypersecretion from the adenomatous thyrotrophs and, consequently, to restore clinical and biochemical euthyroidism in such patients. On the contrary, the inhibitory effects of SMS 201-995 on TSH secretion in patients with nnIST are weaker and transient.     

Hyperthyroidism due to non-tumoural inappropriate TSH secretion. Effect of a long-acting somatostatin analogue (SMS 201-995)

Inappropriate hypersecretion of TSH was investigated in a 25 year old man whose hyperthyroidism had relapsed 4 years after subtotal thyroidectomy. Serum TSH levels were further increased by both TRH and metoclopramide and were partially suppressed by triiodothyronine (120 micrograms/day). The serum alpha-subunit: TSH molar ratio was less than 1.0, and computerised axial tomography showed no evidence of a pituitary tumour. These features are characteristic of inappropriate TSH secretion due to thyrotroph resistance to thyroid hormones. A long-acting somatostatin analogue (SMS 201-995), 50 micrograms injected sc twice-daily for three days, suppressed TSH levels and nearly normalised thyroid hormone levels. Somatostatin analogues may be therapeutically useful in thyrotoxicosis due to non-tumoural inappropriate TSH hypersecretion.     

Anti-iodothyronine autoantibodies in a girl with hyperthyroidism due to pituitary resistance to thyroid hormones.

In the present study, we report the uncommon case of a 9.6-yr-old girl with circulating anti-T3 autoantibodies (T3-Ab) and hyperthyroidism due to inappropriate secretion of TSH (IST). The diagnosis of IST was based on the findings of normal TSH levels (2.4 mU/L) in the presence of high free T4 (28.2 pmol/L) and free T3 (FT3) levels, as measured by direct measurement methods based on "one-step" analog tracer (28.0 pmol/L) and "two-step" Lisophase (13.3 pmol/L) techniques. The discrepancy between the two measurements suggested a methodological interference due to T3-Ab in "one-step" technique, being the "two-step" methodology unaffected by the presence of such autoantibodies. T3-Ab were documented by high nonspecific binding of serum to labeled T3 (38.0% vs 4.3 +/- 2.1% in controls). The clinical picture of hyperthyroidism, the qualitatively normal TSH responses to TRH and T3 suppression tests, the normal pituitary imaging and the values of some parameters of peripheral thyroid hormone action compatible with hyperthyroidism indicated that the patient was affected by pituitary resistance to thyroid hormones (PRTH). Chronic treatment with dopaminergic agent bromocriptine (7.5 mg/day) did not cause TSH secretion to be suppressed, while the administration of thyroid hormone analog TRIAC (1.4 mg/day) inhibited TSH release (from 2.4 to 0.2 mU/L). As a consequence, circulating thyroid hormone levels normalized and euthyroidism was restored. During TRIAC administration, FT3 levels, measured by "one-step" analog tracer technique, gave spuriously high values due to the methodological interference of T3-Ab (15.2 vs 4.3 pmol/L as measured by "two-step" Lisophase technique).(ABSTRACT TRUNCATED AT 250 WORDS)     

TSH-secreting adenomas: rare pituitary tumors with multifaceted clinical and biological features

TSH-secreting pituitary adenomas (TSH-omas) are a rare cause of hyperthyroidism in clinical practice. As their diagnosis is often delayed, these tumors are mostly diagnosed as macroadenomas, preventing an effective and radical cure and leading to serious local and systemic comorbidities. In addition to neurosurgery, medical therapy with the effective and tolerable SS analogs is a fundamental tool for the treatment of TSHomas. We report 3 cases of TSH-macroadenomas which displayed different clinical presentations. All patients showed increased free-thyroid hormone levels with inappropriately normal (2 patients) or high (1 patient) TSH levels. Magnetic resonance imaging (MRI)/computed tomography (CT) evidenced a pituitary macroadenoma and octreoscan was positive in all patients. In the 2 patients who underwent neurosurgery, hormonal hypersecretion by the tumor normalized. Histology showed nuclear pleomorphism and fibrosis, whereas immunohistochemistry showed positivity for TSH and, in a lesser amount, for FSH. In one of these patient (case 1), however, the presence of a tumor remnant inside the left cavernous sinus prompted us, in accordance with the patient, to start therapy with octreotide- long-acting release. As the third patient had a cardiac comorbidity which contraindicated neurosurgery, he underwent satisfactory treatment with long-acting SS analogs alone which normalized thyroid hormone levels. In this case, previous treatment with amiodarone confused and delayed the correct diagnosis of TSH-oma. As a result of improved laboratory and morphological techniques, TSH-omas should currently be diagnosed in early stages, thus enabling most patients to be managed satisfactorily through a combined approach.     

Coexistence of TSH-secreting pituitary adenoma and autoimmune hypothyroidism

OBJECTIVE: TSH-secreting pituitary adenomas account for about 1-2% of all pituitary adenomas. Their diagnosis may be very difficult when coexistence of other diseases masquerades the clinical and biochemical manifestations of TSH-hypersecretion. CLINICAL PRESENTATION: A 41-yr-old female patient, weighing 56 kg, was referred for evaluation of an intra- and suprasellar mass causing menstrual irregularities. Eight yr before, the patient had been given a diagnosis of subclinical autoimmune hypothyroidism because of slightly elevated TSH levels and low-normal free T4 (FT4). Menses were normal. Despite increasing doses of levo-T4 (L-T4; up to 125 microg/day), TSH levels remained elevated and the patient developed mild symptoms of hyperthyroidism. After 7 yr, the menstrual cycle ceased. Gonadotropins were normal, whereas PRL level was elevated at 70 microg/l and magnetic resonance imaging (MRI) of the hypothalamic- pituitary region revealed a pituitary lesion with slight suprasellar extension. The tumor was surgically removed and histological examinations revealed a pituitary adenoma strongly positive for TSH. Three months after surgery the patient was well while receiving L-T4 75 microg/day and normal menses had resumed. MRI of the hypothalamic-pituitary region showed no evidence of residual tumor. At the last follow-up, 16 months after surgery, serum TSH, free T3 (FT3), and FT4 levels were normal. CONCLUSIONS: Coexistence of autoimmune hypothyroidism and TSH-secreting pituitary adenoma may cause further delays in the diagnosis of the latter. In patients with autoimmune hypothyroidism, one should be aware of the possible presence of a TSH-secreting pituitary adenoma when TSH levels do not adequately suppress in the face of high doses of L-T4 replacement therapy and elevated serum thyroid hormone levels.     

Observations concerning the natural history of subclinical hyperthyroidism.

OBJECTIVE: To examine the natural history of a subnormal serum thyroid-stimulating hormone (TSH) concentration with normal concentrations of both serum free thyroxine (FT4) and free triiodothyronine (FT3) (subclinical hyperthyroidism). PATIENTS, DESIGN, AND MEASUREMENTS: A retrospective analysis was undertaken and yielded 16 ambulatory patients who had presented with subclinical hyperthyroidism and were longitudinally followed with measurements of serum TSH and both FT4 and FT3 for a cumulative follow-up of 11 to 36 months. Seven of the patients had subclinical Graves' hyperthyroidism as judged from the presence of thyroid-stimulating immunoglobulins (TSI) in serum, and 9 had multinodular goiter confirmed with ultrasound and no TSI. RESULTS: In the 7 patients with TSI, serum TSH reverted to normal in 5 patients, with disappearance or decrease of TSI in 4, within 3 to 19 months. In 1 patient, subnormal serum TSH accompanied by both normal FT4 and FT3 has persisted for 15 months, and in a second patient serum TSH reverted to normal within 9 months, but at follow-up 27 months later overt hyperthyroidism had emerged. In the 9 patients with multinodular goiter, subnormal serum TSH accompanied by both normal FT4 and FT3 persisted during cumulative follow-up that ranged from 11 to 36 months. CONCLUSIONS: This study suggests that the natural history of subclinical hyperthyroidism is variable, resolving or occasionally evolving in subclinical Graves' disease and persisting unchanged in multinodular goiter.     

TSH-secreting pituitary adenomas: follow-up of 11 cases and review of the literature

Thyrotropin (TSH)-secreting pituitary adenomas account for less than 1% of all pituitary tumors. In the last two decades, their clinical management has changed markedly due to technological advances that made earlier diagnosis possible and the introduction of somatostatin analog therapy. We retrieved the data of 11 patients in Israel diagnosed with TSH-secreting pituitary tumors since 1989. There were six men and five women of mean age 44.8 ± 19.5 years (range 18–80 years). All had elevated thyroxine and triidothyronine levels with nonsuppressed TSH and imaging evidence of a pituitary tumor. In three patients the tumor co-secreted growth hormone. Ten patients had macroadenomas (≥10 mm) and one patient had a microadenoma (<10 mm). Nine patients underwent surgery, and all had postoperative evidence of residual tumor. Ten patients received long-term somatostatin analog therapy (9 postoperatively, 1 primarily), which controlled the hyperthyroidism in all of them. In addition, three patients showed tumor shrinkage and seven, stabilization of tumor growth. In conclusion, in patients with TSH-secreting pituitary adenomas, somatostatin therapy appears to be highly effective in treating hyperthyroidism and in halting tumor growth or promoting tumor shrinkage.     

Surgical Management of Thyrotropin-Secreting Pituitary Adenomas

The reported cases of hyperthyroidism due to a TSH-secreting pituitary adenoma have steadily increased in previous years; however, information about the results and long term outcome after pituitary surgery is scanty.Twenty-four patients with a TSH-secreting adenoma underwent pituitary surgery at our department in the last 15 years. Hypersecretion of other pituitary hormones was diagnosed in 7 patients. Three patients were euthyroid at the time of surgery because of previous ablative thyroid therapies.The success rate of surgery strictly depends on the criteria used. Normalization of elevated FT₃ and FT₄ levels occurred in 17 of the 21 patients with preoperative hyperthyroidism: however, only those with early postoperative undetectable TSH level (12 cases) had no recurrence of disease during follow-up and no residual tumor tissue on postoperative MRI, whereas recurrence of hyperthyroidism occurred in 3 of the 5 patients without postoperative TSH inhibition. All 3 euthyroid patients had a subtotal removal of the tumor, as judged by postoperative MRI.Surgical removal is the therapy of choice of TSH-secreting adenomas, whereas radiotherapy and medical treatment with somatostatin analogues are usually reserved to patients with incomplete tumor removal. A thorough postoperative evaluation is necessary to discriminate between complete and partial remission of disease.     

Hyperthyroidism due to inappropriate secretion of thyrotropin in 10 patients.

PURPOSE: The syndrome of inappropriate thyroid-stimulating hormone (TSH) secretion, characterized by elevated serum free thyroxine and triiodothyronine levels in association with measurable serum TSH concentrations, remains an uncommon cause of hyperthyroidism that is being recognized with increasing frequency. The hyperthyroidism may be due to either neoplastic pituitary TSH secretion or selective pituitary resistance to thyroid hormone. In an effort to better understand this rare cause of hyperthyroidism, we undertook a retrospective analysis of our institution's experience with this condition. PATIENTS: We reviewed our cumulative experience (10 patients) with hyperthyroidism due to the syndrome of inappropriate secretion of TSH. RESULTS: Six patients were diagnosed with TSH-secreting pituitary adenomas and four were found to have selective pituitary resistance to thyroid hormone. One patient with tumor had a TSH-secreting pituitary adenoma in the setting of multiple endocrine neoplasia syndrome. In all patients with tumor, hyperthyroidism was successfully treated with transsphenoidal adenomectomy with or without pituitary radiotherapy. All four patients with pituitary resistance had thyroid ablation or resection prior to their correct diagnosis. Therefore, therapy for this group of patients involved thyroid hormone replacement and efforts to suppress TSH hypersecretion. All 10 patients have done well clinically, with follow-up ranging from 2 weeks to 13 years. CONCLUSIONS: Adequate treatment exists for the two primary causes of TSH hypersecretion. TSH-secreting pituitary adenomas are treated with surgery and, if necessary, adjuvant pituitary radiotherapy. The results are generally good if the tumor is diagnosed and treated at an early stage. Primary therapy for hyperthyroidism due to selective pituitary resistance to thyroid hormone is aimed at suppression of pituitary TSH hypersecretion. The evaluation of any patient with hyperthyroidism must be thorough and, in some cases, should include measurement of TSH to determine the presence of inappropriate secretion. Eliminating this diagnosis will help avoid improper and potentially harmful treatment of hyperthyroid patients.     

The future of somatostatin analogue therapy.

Since its discovery almost 30 years ago, the mode of action and therapeutic applications of somatostatin have been defined. In particular the cloning and characterization of somatostatin receptor subtypes has facilitated the development of high affinity analogues. In the context of pituitary disease, long-acting somatostatin analogues (octreotide, lanreotide) have been used to treat a variety of pituitary tumours but are most efficacious for the treatment of GH and TSH-secreting adenomas. In patients with acromegaly, depot preparations of these analogues are administered intramuscularly every 10-28 days and provide consistent suppression of GH levels to < 5 mU/l in approximately 50-65% of all cases. Even more specific somatostatin receptor analogues are under development. Finally, radiolabelled somatostatin analogue scintigraphy and, in larger doses, therapy, are now established tools in the evaluation and treatment of neuroendocrine tumours.     

Manifestations and prognosis of thyrotropin-secreting pituitary adenomas: a case series of three patients

Introduction

Among pituitary adenomas, thyrotropinomas were previously considered as extremely rare and resistant to therapy. However, the common use of the sensitive TSH measurement and the improvement of pituitary imaging have modified their clinical and hormonal presentation.

Case reports

We here report three cases of TSH secreting pituitary adenoma that highlight the great diversity of the clinical, hormonal and morphological presentation, and their better prognosis. In the presence of an inappropriate TSH secretion, the main differential diagnosis is the syndrome of thyroid hormone resistance. The role of somatostatin analogue prior to the surgical treatment of TSH secreting pituitary adenoma is also underlined in this report.

Conclusion

The increasing frequency and early diagnosis of TSH secreting pituitary adenoma may be explained by ultrasensitive methods now used for TSH measurement and progress in pituitary imaging, mainly with MRI. This changing spectrum in the presentation and the excellent response to somatostatin analogues improved in the prognosis of the disease.     

Hyperthyroidism in a patient with TSH-producing pituitary adenoma coexisting with thyroid papillary adenocarcinoma

A 27-year-old woman who presented with a left thyroid nodule was found to have hyperthyroidism caused by a syndrome of inappropriate secretion of TSH. The levels of free T3, free T4 and TSH were 9.50 pg/mL, 4.05 ng/dL and 2.16 microU/mL, respectively. Magnetic resonance imaging of the head revealed a pituitary macroadenoma. The TSH response to TRH stimulation was normal and responses of other anterior pituitary hormones to stimulation tests were also normally preserved. Administration of octreotide with iodine successfully reversed hyperthyroidism prior to total resection of pituitary adenoma, which was followed by hemithyroidectomy of the left thyroid five months later. Histologically, the resected pituitary adenoma was a TSH-producing adenoma (TSH-oma) and the thyroid nodule was a papillary adenocarcinoma. Serum TSH diminished to undetectable levels immediately following pituitary adenomectomy but gradually normalized over nine months. Coexistence of a TSH-oma with thyroid cancer is very rare and only two similar cases have previously been documented. This combination raises the possibility that TSH may be involved in tumorigenesis in the thyroid gland.     

Effect of long-term treatment with octreotide-lar in a TSH-secreting pituitary macroadenoma and secondary hyperthyroidism

A 74 year-old man was admitted to the hospital for heart failure and atrial fibrillation episodes. He had been irregularly treated for hyperthyroidism during the previous 3 years, with poor control. Thyroid function evaluation showed secondary hyperthyroidism, with high free thyroid hormone levels and TSH inappropriately in the high-normal range (4.2 mU/ml), only slightly responsive to TRH-stimulation (6 microU/ml). Alpha-subunits were hyper-responsive to TRH stimulation (+123%). Thyroid autoimmunity tests were negative and ultrasonography evidenced a diffusely enlarged gland. Magnetic resonance (MR) imaging of the pituitary showed a macroadenoma. The patient underwent transphenoidal adenomectomy, and immunohistochemistry confirmed the diagnosis of a TSH-secreting pituitary macroadenoma. A moderate secondary hyperthyroidism was still present and a new MR evidenced residual disease, involving the right cavernous sinus. A (111)In-octreoscan revealed an increased captation in this area. The patient was treated with octreotide-Lar (20 mg/monthly), which normalized FT3, FT4 and TSH levels already after 3 months of therapy. This effect is still maintained at 42 months of treatment. MR imaging showed a reduction in the residual lesion after 18 months (>50% in comparison with postsurgical MR) and a further decrease after 36 months of treatment). This suggests that the antiproliferative effect on the adenomatous cells is progressive and continues over time. This patients did not receive radiotherapy, so this action is entirely due to the medical treatment. No significant side effects developed and the patient's compliance was good. He has not had further arrhythmic episodes.     

Long-term management in five cases of TSH-secreting pituitary adenomas: a single center study and review of the literature

OBJECTIVE: TSH-secreting pituitary tumors (TSH-omas) are a rare cause of hyperthyroidism and account for <1% of all pituitary adenomas. Failure to recognize the presence of a TSH-oma may result in dramatic consequences such as thyroid ablation that may cause further growth in pituitary tumor. The primary goal of the treatment of TSH-omas is to remove the pituitary tumor. Medical treatment includes dopaminergic agonists or somatostatin analogs. METHODS AND RESULTS: We report five cases of TSH-oma diagnosed between 1997 and 2006 and review the literature. All the patients are females with an age range from 54 to 65 years at diagnosis. Four of the five patients had at least one event of thyroid surgery due to goiter or nodule of unknown dignity. Three of the five patients had a stroke before the diagnosis of TSH-oma, probably due to hypertension, or smoking and contraceptive treatment. One patient with invasive tumor growth received stereotactic radiotherapy (and developed panhypopituitarism after operation), another patient received somatostatin analogs preoperatively and successfully underwent transsphenoidal operation. Three of the five patients received dopaminergic agonists (bromocriptine 5 mg daily or cabergoline 0.5-0.75 mg per week), because they refused surgical therapy or the tumor was stable under dopaminergic therapy. All patients have been followed-up for 2.5-8 years. A normalization of circulating thyroid hormone levels was achieved in all patients. The patient who underwent operation shows no recurrence of the disease. The other patients have a stable pituitary mass without signs of growth. CONCLUSION: We report the successful long-term treatment of TSH-omas with different therapies.     

Diagnosis,pathology, and management of TSH-secreting pituitary tumors. A single-center retrospective study of 20 patients from 1981 to 2014

TSH (thyroid-stimulating hormone)-secreting tumors are the rarest type of pituitary tumor. The objective of this study was to describe initial presentation and follow-up in patients presenting TSH-secreting tumors and to characterize the pathological features, based on a cohort of 20 patients treated in our referral center, between 1981 and 2014. Most of the patients (75%) were female, aged around 50 years (mean: 50 ± 13 years). Initial symptoms were hyperthyroidism (8/20) and/or tumor mass-related symptoms. Median time to diagnosis was 18 months. Biochemical hyperthyroidism was found in 15 patients. Most of the tumors were macroadenomas (75%) and 30% were invasive. Seventeen patients underwent transsphenoidal surgery. All tumors expressed TSH, with > 50% positive cells. Eleven were monohormonal and 6 plurihormonal, expressing βTSH plus growth hormone (GH) and/or prolactin (PRL). Both subtypes showed high expression of Pit-1 and SSTR_2A somatostatin receptors. SSTR₅ was slightly expressed in the plurihormonal subtype. Ki-67 index was elevated (≥ 3%) in only one tumor. Signs of hyperthyroidism were more frequent in the plurihormonal than in the monohormonal subtype. At final follow-up (median: 34.79 ± 66.7 months), 75% of the patients were in complete remission after surgery; persistent hyperthyroidism was controlled by somatostatin analogs, alone (n = 3) or associated to radiotherapy (n = 1). The multidisciplinary approach promoted early diagnosis and control of hyperthyroidism by neurosurgical treatment, associated to somatostatin analogs or not. Clinical/pathological correlations highlighted the variations in immune profiles and in clinical and biological symptoms.     

Effectiveness of Long-Acting Octreotide in Suppressing Hormonogenesis and Tumor Growth in Thyrotropin-Secreting Pituitary Adenomas: Report of Two Cases

Background. The subcutaneous (s.c.) administration of somatostatin analogs, such as octreotide acetate (SMS) and lanreotide, in patients with thyrotropin (TSH)-secreting pituitary adenomas (TSPA's)—thyrotropinomas with residual tumor after initial surgical therapy is effective in controlling hyperthyroidism, as well as curtailing tumor growth in the majority of patients. Long-acting preparations of the above agents, i.e. SMS-LAR and lanreotide-SR, have been synthesized and can be administered as depot injections intramuscularly (i.m.) at intervals of several weeks. Recent studies have reported on preliminary data regarding the use of such preparations in patients with TSPA's. Materials and Methods: We present two cases of TSPA's with residual tumor following transsphenoidal adenomectomy. Neither of the two patients underwent external beam pituitary irradiation. The presence and extent of tumoral TSH hypersecretion was assessed by standard biochemical and dynamic endocrine testing, while tumor size was evaluated by conventional radiographic techniques. Results: In both patients, TSH secretion was effectively suppressed by SMS-LAR. Moreover, administration of this compound halted further tumor growth, as well as resulted in improved patient comfort, for 12 and 10 months respectively. Conclusion: Our date corroborate earlier reports on the usefulness of SMS-LAR in the medical management of patients with TSPA's who have residual disease after initial pituitary surgery and/or irradiation.     

甲状腺功能亢进症316例肝功能某些指标变化的分析

目的探讨甲状腺功能亢进症（甲亢）患者与肝功能的一些指标变化关系。方法对316例甲亢患者行甲功、肝功能检测,指标包括丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、谷胺酰转肽酶（GGT）、碱性磷酸酶（ALP）、血清总胆红素（TBL）;比较分析甲亢性肝功能损害和甲亢无肝功能损害两组之间的游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）、促甲状腺素（TSH）水平;并分析甲亢患者肝功能变化的情况。结果甲亢性肝损害组TSH、FT3、FT4比无肝损害甲亢组高（P〈0．05）,甲亢性肝功能损害时主要以ALP、ALT、AST的异常增高为主;并且FT3、FT4分别与ALP、ALT、AST存在正相关关系,P〈0．05。结论甲亢性肝功能损害（特别是ALP变化）与甲状腺激素水平有密切关系,能否用ALP来协助甲亢诊断和治疗观察值得探讨。