Coexistence of TSH-secreting pituitary adenoma and autoimmune hypothyroidism

Radiological evolution of pituitary hyperplasia in primary hypothyroidism and its differentiation from nonfunctioning pituitary adenoma coexisting with primary hypothyroidism

PURPOSE

In a patient with elevated thyroid stimulating hormone (TSH, >50 µIU/ml) with sellar mass, it is crucial to differentiate isolated pituitary hyperplasia (IPH) from primary hypothyroidism coexisting with nonfunctioning pituitary adenoma (PHCNFPA) pre-operatively to avoid unwarranted surgery in the former condition. Here, we describe patients having pituitary mass/enlargement with markedly elevated TSH (>50 µIU/ml) and attempt to find the differentiating features between IPH and PHCNFPA.

METHODS

This is a retrospective study conducted at a tertiary care center. Case records of patients presenting between January 2020 and December 2022 with elevated TSH (>50 µIU/ml) for whom magnetic resonance imaging (MRI) of the sella was available were reviewed. Demographic details, symptomatology, clinical examination findings, thyroid function tests, data on pituitary hormonal excess and deficiencies, MRI findings, and details regarding levothyroxine supplementation were noted. Based on the final diagnosis, the patients were categorized into two groups: PHCNFPA and IPH.

RESULTS

Five and 11 patients were diagnosed with PHCNFPA and IPH, respectively. The median (IQR) age at presentation of patients with PHCNFPA was significantly higher than that of IPH patients [37 (28-60.5) vs. 21 (10-21.5) years, p: 0.002]. A longer duration of hypothyroid symptoms was noted in the IPH group whereas visual field defects and corticotropin deficiency were more frequent and the pituitary lesion size was greater in PHCNFPA. Thyroid function tests were not different between the two groups. The pituitary enlargement in IPH was initially an increase in pituitary height that progressed to symmetrical nipple-, dome- or tent-shaped enlargement. Besides this characteristic enlargement pattern, isointense appearance on T1-weighted and T2-weighted images, homogeneous contrast enhancement, and prompt regression of pituitary lesion with levothyroxine replacement were characteristic of IPH whereas heterogeneous enhancement, cystic/hemorrhagic change, and ≥Knosp III invasion were characteristic of PHCNFPA. Peripheral rim enhancement and Knosp I-II parasellar extension were not uncommon in patients with IPH and did not distinguish it from PHCNFPA.

CONCLUSIONS

The present study reports the radiological evolution of IPH and a unique series of PHCNFPA along with the distinguishing characteristics between them.

Coexistence of TSH-secreting adenoma and primary hypothyroidism: a case report and review of literature

BACKGROUND

Thyrotropin-secreting adenoma (TSHoma) is the least common type of pituitary adenoma, these patients often present with symptoms of hyperthyroidism. When TSHoma patients combined with autoimmune hypothyroidism, it is critically difficult to diagnose for the specific confusion in the results of thyroid function test.

CASE PRESENTATION

One middle-aged male patient was presented with a sellar tumor on cranial MRI for headache symptoms. After hospitalization, a significant increase in thyrotropin (TSH) was revealed by the endocrine tests, while free thyronine (FT3) and free thyroxine (FT4) decreased, and the diffuse destruction of thyroid gland was revealed by thyroid ultrasound. Based on the endocrine test results, the patient was diagnosed as autoimmune hypothyroidism. After the multidisciplinary discussion, the pituitary adenoma was removed by endoscopic transnasal surgery, until the tumor was completely excised, for which TSHoma was revealed by postoperative pathology. A significant decrease of TSH was revealed by the postoperative thyroid function tests, the treatment for autoimmune hypothyroidism was conducted. After 20 months of follow-up, the thyroid function of patient had been improved significantly.

CONCLUSION

When the thyroid function test results of patients with TSHoma are difficult to interpret, the possibility of combined primary thyroid disease should be considered. TSHoma combined with autoimmune hypothyroidism is rare, which is difficult to diagnose. The multidisciplinary collaborative treatment could help to improve the outcomes of treatment.

Case report: coexistence of primary hyperparathyroidism with giant toxic nodular goiter

BACKGROUND

The coexistence of primary hyperparathyroidism (PHPT) and giant toxic nodular goiter is very rare. Moreover, PHPT could be easily overlooked because hyperthyroidism may also lead to hypercalcemia. A 99mTc-MIBI scan of the parathyroid glands is often negative when they are concomitant.

CASE PRESENTATION

Here, we report a rare case of the coexistence of giant toxic nodular goiter and PHPT that had been ignored for many years but was successfully treated with an ultrasound-guided parathyroid adenoma microwave ablation (MWA).

CONCLUSION

Reoperation for PHPT carries an increased risk of cure failure and complications. Thermal ablation has been proven effective in inactivating hyperfunctioning parathyroid lesions and in normalizing both serum parathyroid hormone (PTH) and calcium.

Syndrome of inappropriate secretion of thyroid-stimulating hormone in a subject with galactorrhea and menstrual disorder and undergoing infertility treatment: Case report

RATIONALE

Syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH) is a rare cause of hyperthyroidism. Thyroid-stimulating hormone (TSH) levels are usually normal or high, and triiodothyronine (FT3) and free thyroxine (FT4) levels are usually high in subjects with SITSH.

PATIENT CONCERN

A 37-year-old woman had experienced galactorrhea and menstrual disorder for a couple of years before. She had undergone infertility treatment in 1 year before, hyperthyroidism was detected and she was referred to our institution.

DIAGNOSIS

She was suspected of having SITSH and was hospitalized at our institution for further examination. The data on admission were as follows: FT3, 4.62 pg/mL; FT4, 1.86 ng/dL; TSH, 2.55 μIU/mL. Although both FT3 and FT4 levels were high, TSH levels were not suppressed, which is compatible with SITSH. In addition, in brain contrast-enhanced magnetic resonance imaging, nodular lesions were observed in the pituitary gland with a diameter of approximately 10 mm. In the thyrotropin-releasing hormone load test, TSH did not increase at all, which was also compatible with TSH-secreting pituitary adenoma. In the octreotide load test, the TSH levels were suppressed. Based on these findings, we diagnosed this subject as SITSH.

INTERVENTIONS

Hardy surgery was performed after the final diagnosis. In TSH staining of the resected pituitary adenoma, many TSH-producing cells were observed. These findings further confirmed the diagnosis of pituitary adenoma producing TSH.

OUTCOMES

Approximately 2 months after the operation, TSH, FT3, and FT4 levels were normalized. Approximately 3 months after the operation, she became pregnant without any difficulty.

LESSONS

We should consider the possibility of SITSH in subjects with galactorrhea, menstrual disorders, or infertility. In addition, we should recognize that it is very important to repeatedly examine thyroid function in subjects with galactorrhea, menstrual disorder, or infertility.

Cosecreting TSH/GH pituitary adenomas-an 8-year experience in a single tertiary center

PURPOSE

Thyrotropin-secreting pituitary adenoma is a rare disorder and was recently classified as an aggressive tumor in the World Health Organization guidelines. The number of available studies on cosecreting thyrotropin/growth hormone pituitary adenoma is especially limited.

METHODS

A single-center retrospective analysis of patients with thyrotropin/growth hormone pituitary adenoma was performed at Peking Union Medical College Hospital, one of the largest pituitary care centers in China, from January 2012 to January 2020. Additionally, data about cosecreting thyrotropin/growth hormone pituitary adenoma were collected and analyzed. The diagnosis, therapy and follow-up were all compared to that of solo-secreting thyrotropin pituitary macroadenoma.

RESULTS

Twelve patients (10.81%) were identified with thyrotropin/growth hormone pituitary adenoma at Peking Union Medical College Hospital within 8 years, all of which were classified as macroadenoma. Compared with solo-secreting thyrotropin pituitary macroadenoma, thyrotropin/growth hormone pituitary adenoma presented with a higher proportion of cavernous sinus invasion (50%) and had a larger maximum tumor diameter. The patients had a lower surgical complete remission rate and a worse prognosis. Interestingly, they revealed a striking phenomenon of "solo part remission".

CONCLUSIONS

Thyrotropin/growth hormone pituitary adenoma is rare. Some patients do not present with the typical manifestations; however, the possibility of a cosecretion tumor should not be excluded. A preoperative comprehensive evaluation of anterior pituitary hormones is necessary. Thyrotropin/growth hormone pituitary adenoma revealed a high tendency of invasion, and the prognosis of patients with thyrotropin/growth hormone pituitary adenoma was poor. If necessary, timely postoperative drug administration or radiotherapy should be carried out.

A Thyroid-stimulating Hormone (TSH) Producing Adenoma in a Patient with Severe Hypothyroidism: Thyroxine Replacement Reduced the TSH Level and Tumor Size

We treated an extremely rare thyroid-stimulating hormone (TSH)-producing pituitary adenoma in a 63-year-old woman with severe hypothyroidism due to autoimmune thyroiditis. She was presented with dizziness and fatigue. The blood level of TSH, prolactin, and fT4 was 288.2 μIU/mL, 72.9 ng/mL, and 0.24 ng/dL, respectively. Magnetic resonance imaging demonstrated a large pituitary tumor, 31 mm in height, and a normal pituitary gland. Preoperative thyroxine replacement reduced the TSH level to 2.05 μIU/mL and produced a significant reduction in the tumor volume. Histopathologically, the surgically removed tumor was a TSH-producing pituitary adenoma.

DIAGNOSIS OF ENDOCRINE DISEASE: Diagnostic approach to TSH-producing pituitary adenoma

Thyrotropin (TSH)-secreting adenomas (TSHomas) are the rarest form of pituitary adenomas, and most endocrinologists will see few cases in a lifetime, if any. In most cases, the diagnostic approach is complicated and cases may be referred after being presented as a syndrome of inappropriate TSH secretion or as a pituitary mass. This review aims to cover the past, present and possible future diagnostic approaches to TSHomas, including different clinical presentations, laboratory assessment and imaging advances. The differential diagnoses will be discussed, as well as possible coexisting disorders. By evaluating the existing reports and reviews describing this rare condition, this review aims to present a clinically practical suggestion on the diagnosic workup for TSHomas, Major advances and scientific breakthroughs in the imaging area in recent years, facilitating diagnosis of TSHomas, support the belief that future progress within the imaging field will play an important role in providing methods for a more efficient diagnosis of this rare condition.

[Clinical and morphological characteristics, diagnostic criteria, and outcomes of surgical treatment of TSH-secreting pituitary adenomas]

Thyrotropinomas (TSH-secreting tumors) are a rare type of pituitary adenomas, which account for about 0.5-2.0% of all pituitary tumors. The criterion of thyrotropinoma is visualization of the tumor in the presence of a normal or elevated level of the thyroid-stimulating hormone (TSH) in the blood and elevated concentrations of free T4 (fT4) and free T3 (fT3).

OBJECTIVE

To study the clinical, diagnostic, and morphological characteristics and treatment outcomes of TSH-secreting pituitary tumors.

MATERIAL AND METHODS

The study included 21 patients aged from 15 to 67 years with pituitary adenoma and a normal or elevated blood TSH level combined with elevated fT4 and fT3 levels who were operated on at the Neurosurgical Institute in the period between 2002 and 2015. Before surgery, in the early postoperative period, and 6 months after surgery, the patients were tested for levels of TSH, fT4, fT3, prolactin, cortisol, the luteinizing hormone (LH), the follicle-stimulating hormone (FSH), estradiol/testosterone, and the insulin-like growth factor (IGF-1). The thyroid status was evaluated using the following reference values: TSH, 0.4-4.0 mIU/L; fT4, 11.5-22.7 pmol/L; fT3, 3.5-6.5 pmol/L. An immunohistochemical study of material was performed with antibodies to TSH, PRL, GH, ACTH, LH, FSH, and Ki-67 (MiB-1 clone); in 13 cases, we used tests with antibodies to somatostatin receptors type 2 and 5 and to D2 subtype dopamine receptors.

RESULTS

Thyrotropinomas were detected in patients aged from 15 to 67 years (median, 39 years), with an equal rate in males (48%) and females (52%). Before admission to the Neurosurgical Institute, 11 (52%) patients were erroneously diagnosed with primary hyperthyroidism; based on the diagnosis, 7 of these patients underwent surgery on the thyroid gland and/or received thyrostatics (4 cases). Hyperthyroidism symptoms were observed in 16 (76%) patients. The blood level of TSH was 2.47-38.4 mIU/L (median, 6.56); fT4, 22.8-54.8 nmol/L (median, 36); fT3, 4.24-12.9 pmol/L (median, 9.66). Tumors had the endosellar localization in 4 (19%) cases and the endo-extrasellar localization in 17 (91%) cases. Total tumor resection was performed in 7 (33%) patients. All these tumors had the endosellar and endo-suprasellar localization. No total resection was performed in patients with infiltrative growth of adenoma (invading the skull base structures). An immunohistochemical study of tumor resection specimens detected only TSH expression in 3 (14%) cases; 18 (86%) tumors were plurihormonal and secreted TSH and GH and/or PRL. Of 13 tumors, expression of the type 2 dopamine receptor was detected in 9 (69%) cases; expression of somatostatin receptors type 5 and type 2 was found in 6 (46%) and 2 (15%) cases, respectively.

CONCLUSION

The criterion for total tumor resection was a postoperative decrease in the TSH level to 0.1 mIU/L or less. Total resection was performed in 33% of patients with tumors of only the endosellar and endo-suprasellar localization. In most cases, tumors were plurihormonal and secreted TSH and GH and/or PRL.

Thyrotropin-secreting pituitary adenomas: epidemiology, diagnosis, and management

Inappropriate secretion of TSH was first described in 1960 in a patient with evidence of hyperthyroidism and expanded sella on imaging. It was later found that a type of pituitary adenoma that secretes TSH (thyrotropinoma) was the underlying cause. The objective of the present review article is to summarize data on the epidemiology, pathogenesis, diagnosis, and management of thyrotropinomas. The prevalence of thyrotropinomas is lower than that of other pituitary adenomas. Early diagnosis is now possible thanks to the availability of magnetic resonance imaging and sensitive laboratory assays. As a corollary, many patients now present earlier in the course of their disease and have smaller tumors at the time of diagnosis. Treatment also has evolved over time. Transsphenoidal surgery is still considered definitive therapy. Meanwhile, radiation therapy, including radiosurgery, is effective in achieving tumor control in the majority of patients. In the past, radiation therapy was used as second line treatment in patients with residual or recurrent tumor after surgery. However, the availability of somatostatin analogs, which can lead to normalization of thyroid function as well as shrink these tumors, has led to an increase in the role of medical therapy in patients who are not in remission after pituitary surgery. In addition, dopamine agonists have shown some efficacy in the management of these tumors. Better understanding of the molecular pathogenesis of thyrotropinomas may lead to rationally designed therapies for patients with thyrotropinomas.

When thyroid hormone replacement is ineffective?

PURPOSE OF REVIEW

In this article, we will consider the failure of thyroid hormone replacement therapy to normalize serum thyroid stimulating hormone concentrations. We will review circumstances and causes for failures, discuss pertinent unpublished personal cases of didactical value, and provide practical suggestions for providers encountering patients with similar presentations.

RECENT FINDINGS

Recent data are available on the benefit of novel formulations of levothyroxine therapy on malabsorption.

SUMMARY

Most frequently, reasons for ineffectiveness are noncompliance, inappropriate administration of levothyroxine, gastrointestinal disorders, and drug interactions. The diagnostic work-up should include careful history to elucidate the potential reasons for the ineffective therapy.

Concomitant Graves hyperthyroidism with thyrotrophin-secreting pituitary adenoma

The relationship of autoimmune thyroid disease and TSH-producing pituitary tumor is rarely found. We report two patients with hyperthyroidism, a 27-year-old man and a 28-year-old woman, who were diagnosed with Graves hyperthyroidism with elevated free thyroxine (FT4), suppressed TSH and positive thyrotropin receptor autoantibodies. After treatment with antithyroid drugs, FT4 did not return to normal, and serum TSH levels were found to be above-normal range. Pituitary tumors were subsequently found via pituitary magnetic resonance imaging (MRI). We suggest that Graves hyperthyroidism concomitant with TSH-producing pituitary tumor be kept in mind, as it may confuse the therapeutic course of hyperthyroidism and make it more complicated.

Pituitary tumours: TSH-secreting adenomas

Thyrotropin-secreting pituitary adenomas (TSHomas) are a rare cause of hyperthyroidism and account for less than 2% of all pituitary adenomas. In the last years, the diagnosis has been facilitated by the routine use of ultra-sensitive TSH immunometric assays. Failure to recognise the presence of a TSHoma may result in dramatic consequences, such as improper thyroid ablation that may cause the pituitary tumour volume to further expand. The diagnosis mainly rests on dynamic testing, such as T3 suppression tests and TRH, which are useful in differentiating TSHomas from the syndromes of thyroid hormone resistance. The first therapeutical approach to TSHomas is the pituitary neurosurgery. The medical treatment of TSHomas mainly rests on the administration of somatostatin analogues, such as octreotide and lanreotide, which are effective in reducing TSH secretion in more than 90% of patients with consequent normalisation of FT4 and FT3 levels and restoration of the euthyroid state.

New onset Graves' disease as a cause of an adrenal crisis in an individual with panhypopituitarism: brief report

46 year old patient was admitted as an emergency with vomiting, hypotension and serum cortisol of 0,940 μg/dl (26 nmol/l) indicative of adrenal failure. Despite previous history of panhypopituitarism he was found to be hyperthyroid [free T₄ 6.32 ng/dl (ref. range: 0.93–1.7), free T₃ 22.21 pg/ml (ref. range: 1.8–4.6)]. He was fit and well till the age of 45. Eight months prior to this hospitalisation he presented with diabetes insipidus and was found to have a large cystic tumour in the area of the pituitary gland. Surgery was only partially successful and histologically the tumour was diagnosed as craniopharyngioma. Endocrine assessment revealed deficiency in ACTH-cortisol, growth hormone, and gonadotropin, as well as low-normal free T₄. On the day of his emergency admission he looked ill and dehydrated, though was fully conscious and cooperative. Heart rate was 120 beats/min (sinus rhythm), blood pressure 85/40 mm Hg. There were no obvious features of infection, but there was marked tremor and thyroid bruit. He received treatment with intravenous fluids and hydrocortisone. L-thyroxine was stopped. Administration of large dose of methimazole (60 mg/day) resulted in gradual decrease in free T₄ and free T₃ (to 1.76 ng/ml, and 5.92 pg/ml, respectively) over a 15-day period. The patient was found to have increased titre of antithyroperoxidase (anti-TPO) and anti-TSH receptor (anti-TSHR) antibodies [2300 IU/l (ref. range <40) and 3.6 IU/l (ref. range <1.0), respectively]. He was referred for radioactive iodine treatment. Iodine uptake scan performed prior to radioiodine administration confirmed uniformly increased iodine uptake consistent with Graves' disease.

Our case illustrates coexistence of hypopituitarism and clinically significant autoimmune thyroid disease. The presence of hypopituitarism does not preclude the development of autoimmune thyrotoxicosis.