Thyrotropin secreting pituitary adenoma associated with hypopituitarism and diabetes insipidus in an adolescent boy

Challenges in the Management of a 7-Year-Old Child with Thyrotropin-Secreting Pituitary Adenoma and the Review of the Literature

INTRODUCTION

Thyrotropin-producing pituitary adenoma (TSHoma) is a very rare disease, representing less than 1% of the pituitary tumours and presenting with elevated thyroid hormones and normal/high TSH concentrations.

CASE PRESENTATION

A 7-year-old boy with nervousness was referred by his psychiatrist for elevated free T4, T3, and TSH levels. Initial evaluation revealed an elevated α-subunit. Pituitary magnetic resonance imaging (MRI) demonstrated a macroadenoma. The patient underwent a trans-sphenoidal tumour resection (TSS) which showed positive immunohistochemical staining for TSH, growth hormone, and prolactin in tumoral tissue. Euthyroidism was achieved for 1 year after TSS, then recurrence of tumour with elevated TSH and thyroid hormone levels necessitated a re-operation with TSS followed by gamma-knife radiosurgery. The euthyroid state was achieved and lasted for 2.5 years this time, but due to the recurrence, medical treatment had been commenced with cabergoline and octreotide. Euthyroidism was maintained for the last 4 years on monthly octreotide treatment. A repeat MRI demonstrated no pituitary mass, but a mass in the sphenoidal sinus had been detected. Removal of this mass by surgery did not achieve euthyroidism. 68Ga-DOTA-TATE positron emission tomography/computed tomography showed residual tissue extending from the pituitary region to the sphenoid sinus. The patient's bone age was advanced by 2 years at diagnosis which became 4 years in 1 year after the diagnosis and remained so throughout follow-up, leading to a final height of -3.3 SDS below his target height at the age of 16 years.

CONCLUSION

The diagnosis, treatment, and follow-up of TSHomas are challenging, and short stature due to accelerated bone maturation is a complication of paediatric TSHomas.

Central Hyperthyroidism due to Thyroid-Stimulating Hormone-Secreting Pituitary Microadenoma in an Adolescent Boy: Case Report and Review of the Literature

Thyroid-stimulating hormone- (TSH-) secreting pituitary adenoma (TSH-oma) is a rare cause of secondary hyperthyroidism and can be misdiagnosed as primary hyperthyroidism. We report a case of a 15-year-old male patient who was one of two monozygotic twins and exhibited hyperthyroidism syndrome. The laboratory results showed secondary hyperthyroidism, with increased levels of free T3 (FT3) and free T4 (FT4) and no TSH inhibition. Magnetic resonance imaging (MRI) and histopathological examination of the pituitary gland confirmed pituitary microadenoma. The patient was treated with methimazole, propranolol, and somatostatin analogs to restore euthyroidism before undergoing an endoscopic transsphenoidal resection of the pituitary tumor. After surgery, the hyperthyroidism symptoms improved, thyroid hormones normalized, and MRI of the pituitary gland showed the complete removal of the tumor with no recurrence after 2 years of follow-up.

Clinical and Therapeutic Characteristics of Pituitary TSH-Secreting Adenoma in Adolescent-Onset Patients: Six Case Studies and Literature Review

BACKGROUND

Thyrotropin-secreting adenoma (TSH-oma) is a very rare kind of functional pituitary adenoma, especially that which occurs in adolescents. However, its potential clinical and therapeutic characteristics are still unknown.

OBJECTIVES

The study was aimed to summarize the clinical and therapeutic characteristics of patients with adolescent-onset TSH-oma.

METHODS

We retrospectively analyzed six (4.1%) adolescent-onset TSH-oma cases from 148 patients who were diagnosed with TSH-oma at our hospital between January 2012 and October 2020. A literature review was performed on the PubMed online database, and 14 adolescent-onset TSH-oma cases were retrieved. Then, the characteristics of clinical manifestations, treatment outcomes, and follow-ups were analyzed and compared to the adult TSH-oma patients.

RESULTS

Altogether, 20 adolescent-onset cases were included in this study having mean onset age of 13.4 ± 3.3 years. Males were found to be slightly predominant (M: F = 1.5:1) in our study. The median baseline levels of TSH, FT3, and FT4 in adolescent-onset cases were found to be 6.30 [interquartile range (IQR) 9.82] µIU/ml, 9.18 (IQR 11.61) pg/ml, and 3.22 (IQR 1.90) ng/dl, respectively, which were all significantly higher than the adult patients of our hospital. Also, the adolescent-onset cases showed more large tumor ratio (36.8% vs. 9.3%, p = 0.007) compared to the adult patients. Compared to the patients of all ages in the literature, the biochemical remission rate of SSAs (57.1%) and remission rate of TSS (38.9%) were found to be considerably lower in adolescent-onset patients, while the recurrence rate (44.4%) was found to be considerably higher.

CONCLUSIONS

Adolescent-onset TSH-oma patients showed higher TSH and thyroid hormone levels, more large tumors, and worse treatment outcomes than adult cases. Hence, early diagnosis, multidisciplinary therapy, and close follow-up should be highlighted to improve the prognosis.

Monomorphous Plurihormonal Pituitary Adenoma of Pit-1 Lineage in a Giant Adolescent with Central Hyperthyroidism

Thyrotropin (TSH)-secreting pituitary adenomas are exceedingly rare at the pediatric age and no cases of co-secretion with other pituitary hormones in these tumors have been described in this age range. We present a case of a monomorphous plurihormonal pituitary adenoma that co-secreted TSH and GH in a pediatric patient. A 13-year-old male presented with increasing height velocity (17.75 cm/year, 9.55SD), weight loss, and visual impairment. Initial biochemical evaluations revealed secondary hyperthyroidism. A giant pituitary tumor compressing the surrounding structures was detected by magnetic resonance, and a transsphenoidal surgery was initially performed. Pathological examinations revealed an atypical, monomorphous plurihormonal Pit-1 lineage tumor with mixed features of silent subtype 3 adenoma and acidophil stem cell adenoma. In the postoperative period, secondary hyperthyroidism recurred with high levels of both GH and IGF1. In addition, due to tumor re-growth, a multimodality treatment plan was undertaken including surgery, somatostatin analogs, and radiotherapy. We report the first pediatric case of a plurihormonal TSH- and GH-secreting pituitary adenoma, further expanding the clinical manifestations of pediatric pituitary tumors. Comprehensive pathological evaluation and close follow-up surveillance are crucial to the prompt delivery of the best therapeutic options in the context of this particularly aggressive pituitary tumor.

Asymptomatic thyrotropin-secreting pituitary macroadenoma in a 13-year-old girl: successful first-line treatment with somatostatin analogs

BACKGROUND

Thyrotropin-secreting pituitary adenomas (TSHomas) are an extremely rare cause of hyperthyroidism. Up to now there are only few cases reported in the pediatric age range. Thefirst therapeutic option is surgical resection, whereas medical treatment with somatostatin analogs has been reported only in cases wherein surgery was unsuccessful.

PATIENT FINDINGS

A 13-year-old girl was referred to our clinic for incidental finding of increased circulating free thyroid hormones in the presence of detectable TSH concentrations. She had no signs/symptoms of thyrotoxicosis. Resistance to thyroid hormone was excluded due to the lack of TSH response after thyrotropin-releasing hormone (TRH) stimulation test. Cerebral magnetic resonance imaging showed the presence of a large pituitary macroadenoma, with intra- and suprasellar extension. We decided to treat this patient with somatostatin analog as a first-line therapy because of high surgery risks due to the tumor dimensions. The response to medical treatment was excellent, with rapid and significant tumor shrinkage. No major side effects were reported. The patient developed central hypothyroidism that was corrected with L-thyroxine therapy.

SUMMARY

We report the first pediatric case of TSHoma treated with somatostatin analog as a first-line therapy. The diagnosis was challenging because of the insidious and asymptomatic presentation of the tumor.

CONCLUSIONS

We conclude that somatostatin analogs should be considered as first choice, bridge-to-surgery treatment in young patients, in order to reduce neurosurgical complications and prevent hypopituitarism during pubertal development.

Thyroid-stimulating hormone (thyrotropin)-secretion pituitary adenoma in an 8-year-old boy: case report

In this report, an extremely rare case of pediatric thyrotropin-secreting pituitary macroadenoma (TSHoma) is described. An 8-year-old boy, complaining of unsteady gait, was suspected of endocrinopathy because of emaciation and muscle weakness of the legs. Endocrinological work-up established a diagnosis of hyperthyroidism due to syndrome of inappropriate secretion of TSH. Magnetic resonance imaging showed a pituitary macroadenoma with suprasellar and sphenoidal extension without cavernous sinus invasion. He underwent an endoscopic endonasal transsphenoidal adenomectory due to the diagnosis of TSHoma. The adenoma was soft and it was totally removed. Histopathological staining confirmed diagnosis of TSHoma. Postoperative evaluation revealed a subnormal level of TSH (from 13-21 to 0.03 micro U/ml), normalization of alpha-subunit (from 10.0 to 0.09 ng/ml), and as a result, hypothyroidism. The boy left the hospital with oral levothyroxine that continued until 12 months of discharge. The present 8-year-old case is the youngest case to the best of our knowledge based on a bibliographical search. Reasons for endocrinological remission following adenomectomy are (1) correct diagnosis without delay: lack of cavernous sinus invasion, (2) soft and non-fibrous adenoma tissue, and (3) endoscopic technique with wide vision and illumination: safe even for a 8-year-old child. Early recognition/detection and pituitary-conserving adenomectomy can cure TSHoma and avoid long-term medical therapy and/or irradiation, which contribute to the best interests of patients with TSHoma.

Thyrotropin-secreting pituitary adenoma in an adolescent boy: challenges in management

Thyrotropinomas tend to be aggressive, invasive tumors that are difficult to resect because of their marked fibrosis and their proximity to vital structures such as the optic chiasm. The latter characteristic also limits the use of radiation therapy. In the few cases reported of children younger than 18 years whose thyrotropinomas were treated surgically, the results were disappointing. We present here the case of a 16-year-old boy with a thyrotropin-secreting pituitary macroadenoma who underwent partial resection via a transsphenoidal approach and was left with significant residual tumor and continued hyperthyroidism. He subsequently received 4 years of long-acting release somatostatin therapy, during which he has remained euthyroid without requiring antithyroid medication. To our knowledge, this is thus far the longest duration of somatostatin therapy in the pediatric age group. This regimen also achieved a decrease in compression of the optic nerve and prevented further tumor growth. We review here the current literature on somatostatin analog treatment including molecular mechanisms and promising new treatment modalities, such as the heterodimerization of dopamine and somatostatin receptors. We conclude that this has been a useful adjuvant treatment for our adolescent patient.

Thyrotoxicosis in children

Graves' disease is the predominant cause of hyperthyroidism in the pediatric age group. Other disorders must be recognized, however, because adequate management relies on a precise diagnosis. Careful monitoring of the thyroid status is required during this active phase of growth and development.