Primary hypothyroidism mimicking a pituitary macroadenoma: regression after thyroid hormone replacement therapy

Pituitary Macroadenoma Secondary to Congenital Hypothyroidism With Growth Failure and Developmental Delay: A Rare Presentation

Reactive pituitary hyperplasia can develop as a pituitary (pseudo) macroadenoma in the case of primary hypothyroidism. Hypothyroidism-induced pituitary hyperplasia (PHPH) can be managed medically. Surgery should not be performed if this condition is misdiagnosed as an adenoma. Primary hypothyroidism is a well-known cause of children's slow linear growth. Anterior pituitary enlargement is a rare symptom of severe or long-term illness (pituitary pseudotumor). Thyroid-stimulating hormone-secreting adenomas (TSHomas) are the rarest type of pituitary adenomas, with most endocrinologists seeing just a few cases throughout their lives. In most situations, the diagnosis is difficult, and patients may be referred after presenting with a condition of excessive thyroid-stimulating hormone secretion or a pituitary tumor. In this case study, we describe a 3.5-year-old girl who was referred to our hospital for a surgical assessment of a suspected pituitary neoplastic lesion. It was later determined that the suspected lesion was really pituitary hyperplasia brought on by primary hypothyroidism. Levothyroxine was started, and the dose was increased. The patient was advised to follow up to see if pituitary macroadenoma had responded to levothyroxine supplementation. Pituitary enlargement (pseudotumor of the pituitary gland) is a rare complication of primary hypothyroidism. Early diagnosis and treatment are critical for children with severe primary hypothyroidism to maintain their final height, as late diagnosis nearly always leads to a decline in adult stature. Pituitary macroadenoma secondary to severe hypothyroidism does not need risky and expensive surgical intervention. Because PHPH is rare in children, more credible information is needed to have a better knowledge of how the disease progresses and to develop scientific diagnostic criteria.

Hashimoto's thyroiditis, vitiligo, anemia, pituitary hyperplasia, and lupus nephritis-A case report of autoimmune polyglandular syndrome type III C + D and literature review

Objective

This study aims to summarize the clinical characteristics of one teenager with autoimmune polyglandular syndrome (APS) type III C + D to improve the understanding of APS III C + D and its effect of thyroid function.

Methods

This article reported the clinical manifestations, laboratory examinations, treatment methods, and outcomes of an adolescent with anemia admitted to the Pediatrics Department of Tianjin Medical University General Hospital in July 2020 and reviewed the literature.

Results

A girl, aged 13 years and 1 month, was admitted to the hospital due to anemia for more than 4 years and episodic abdominal pain for 1 week. Four years ago, the girl went to a local hospital for "vitiligo", and a routine blood test revealed anemia. The lowest hemoglobin (HGB) was 61 g/L, and the blood test revealed iron deficiency anemia. She had no menstrual cramps for 2 months. Urine routine showed protein 3+∼4+ and 258 red blood cells (RBCs)/high-power field. Urine protein was 3,380 mg/24 h. Free thyroxine was low, thyroid-stimulating hormone was >100 uIU/ml, thyroid peroxidase antibody was >1,000 IU/ml, and thyroglobulin antibody and thyrotropin receptor antibody were negative. Pituitary magnetic resonance imaging showed a mass in the sellar region with a uniform signal and a maximum height of about 15.8 mm. The result of the antinuclear antibody was 1:80 homogeneous type, and anti-dsDNA and anticardiolipin antibodies IgA and IgM were slightly higher. Thyroxine and iron were given for 1 month, menstruation resumed, and urine protein and RBC count decreased. After 5 months of treatment, free thyroid function, HGB, RBCs in urine, and pituitary returned to normal. Later, a renal biopsy showed changes in focal proliferative glomerulonephritis, and the girl was diagnosed with lupus glomerulonephritis type III. After 3 days of shock therapy with methylprednisolone, prednisone, mycophenolate mofetil, and other treatments were administrated for 1 year. At the time of writing, urine protein was 280 mg/24 h.

Conclusion

Co-occurrence of Hashimoto's thyroiditis, vitiligo, anemia, pituitary hyperplasia, and lupus nephritis is rare. It is very important to pay attention to the screening of thyroid function.

Imaging Errors in Distinguishing Pituitary Adenomas From Other Sellar Lesions

BACKGROUND

Pituitary adenomas and nonadenomatous lesions in the sellar region may be difficult to distinguish by imaging yet that distinction is critical in guiding management. The nature of the diagnostic errors in this setting has not been well documented.

METHODS

Two neurosurgeons and 2 neuroradiologists of differing experience levels viewed deidentified MRIs of 18 nonadenomatous sellar lesions and 21 adenomas. They recorded their diagnoses, the imaging features they used to make those diagnoses, and their confidence in making those diagnoses.

RESULTS

Among the 18 nonadenoma cases, 11 (61%) were incorrectly diagnosed as adenoma by at least 1 reader, including Rathke cleft cyst, plasmacytoma, aneurysm, craniopharyngioma, chordoma, Langerhans cell histiocytosis, metastasis, and undifferentiated sinonasal carcinoma. Among the 21 adenoma cases, 8 (38%) were incorrectly diagnosed by at least 1 reader as craniopharyngioma, Rathke cleft cyst, sinonasal carcinoma, hemangioblastoma, and pituitary hyperplasia. Incorrect imaging diagnoses were made with high confidence in 13% of readings. Avoidable errors among the nonadenomatous cases occurred when readers failed to appreciate that the lesion was separate from the pituitary gland. Unavoidable errors in those cases occurred when the lesions were so large that the pituitary gland had been obliterated or the imaging features of a nonadenomatous lesion resembled those of a cystic pituitary adenoma. Avoidable errors in misdiagnosis of adenomas as nonadenomas occurred when readers failed to appreciate features highly characteristic of adenomas. An unavoidable error occurred because a cystic adenoma had features correctly associated with craniopharyngioma.

CONCLUSIONS

Errors in imaging differentiation of pituitary adenoma from nonadenomatous lesions occurred often and sometimes with high confidence among a small sample of neurosurgeons and neuroradiologists. In the misdiagnosis of nonadenomatous lesions as adenomas, errors occurred largely from failure to appreciate a separate pituitary gland, but unavoidable errors occurred when large lesions had obliterated this distinguishing feature. In the misdiagnosis of adenomas as nonadenomatous lesions, avoidable errors occurred because readers failed to recognize imaging features more characteristic of adenomas and because cystic adenomas share features with craniopharyngiomas and Rathke cleft cysts. Awareness of these errors should lead to improved management of sellar lesions.

Pituitary Macroadenoma and Severe Hypothyroidism: The Link between Brain Imaging and Thyroid Function

In case of primary hypothyroidism, reactive pituitary hyperplasia can manifest as pituitary (pseudo) macroadenoma. We report the case of a 12-year-old boy who was evaluated for impaired growth velocity and increased body weight. Because of low insulin-like growth factor 1 levels and poor response to the growth hormone stimulation test, brain magnetic resonance imaging was performed and a pituitary macroadenoma was found. Treatment with levothyroxine was started, and thyroid function was evaluated approximately every 40 days to titrate the dosage. After few months of therapy, the size of the macroadenoma decreased and growth hormone secretion normalized. The pituitary returned to normal size in approximately 5 years. The boy went through puberty spontaneously and reached a normal adult height. In a patient affected by primary hypothyroidism, reactive pituitary hyperplasia can cause growth hormone deficiency; however, growth hormone secretion usually normalizes after starting levothyroxine treatment. Pituitary macroadenoma can be difficult to distinguish from severe pituitary hyperplasia; however, pituitary macroadenomas are rare in childhood, and our clinical case underlines how the hormonal evaluation is essential to achieve a correct diagnosis and prevent unnecessary surgery in a context of pituitary mass.

Pituitary hyperplasia in childhood primary hypothyroidism: a review

INTRODUCTION

Pituitary hyperplasia following primary hypothyroidism in pediatric age group population is considered rare with reports of unnecessary neurosurgical intervention for this medically treatable condition. Given the paucity of information on this topic, it is timely to provide clinicians with a comprehensive summary of available research.

METHODS

A search of published studies in Pubmed, PsychInfo and Cochrane Database with the terms "pituitary hyperplasia" or "pituitary hypertrophy" and "hypothyroidism" was performed and the results filtered for English language, pediatric (0-18 years) population and CT or MRI confirmed findings. 55 studies met the inclusion criteria. Data for a total of 110 patients with pituitary hyperplasia following primary hypothyroidism were extracted. The study population included 29 males and 81 females (M: F= 0.35:1). Patient age varied from 3 weeks to 18 years with a mean age of 10.22 years.

RESULTS

The most common clinical presentations included growth retardation, constipation and features of myxedema which were present in 78, 36 and 18 percent of children included in our review. Neuroimaging showed the mean (SD) pituitary height being 13.48 mm (4.72 mm). All of the patients achieved resolution of their pituitary mass and clinical as well as biochemical abnormalities 1 to 26 months after initiation of thyroid hormone replacement therapy, with an average time interval of 7.22 months. Our review has tried to delve in the pathophysiology as well as clinical, biochemical and radiological aspects of pediatric pituitary hyperplasia secondary to primary hypothyroidism and provide recommendations for treatment and follow-up. This may help anyone concerned gain a substantial knowledge on this topic.

Neurobiology of puberty and its disorders

Puberty, which in humans is considered to include both gonadarche and adrenarche, is the period of becoming capable of reproducing sexually and is recognized by maturation of the gonads and development of secondary sex characteristics. Gonadarche referring to growth and maturation of the gonads is fundamental to puberty since it encompasses increased gonadal steroid secretion and initiation of gametogenesis resulting from enhanced pituitary gonadotropin secretion, triggered in turn by robust pulsatile GnRH release from the hypothalamus. This chapter reviews the development of GnRH pulsatility from before birth until the onset of puberty. In humans, GnRH pulse generation is restrained during childhood and juvenile development. This prepubertal hiatus in hypothalamic activity is considered to result from a neurobiological brake imposed upon the GnRH pulse generator resident in the infundibular nucleus. Reactivation of the GnRH pulse generator initiates pubertal development. Current understanding of the genetics and physiology of the brake will be discussed, as will hypotheses proposed to account for timing the resurgence in pulsatile GnRH and initiation of puberty. The chapter ends with a discussion of disorders associated with precocious or delayed puberty with a focus on those with etiologies attributed to aberrant GnRH neuron anatomy or function. A pediatric approach to patients with pubertal disorders is provided and contemporary treatments for both precocious and delayed puberty outlined.

Thyroid hormone therapy in congenital hypothyroidism and pediatric hypothyroidism

The evaluation and management of hypothyroidism in children are similar to adults, but there are important differences based on the dependence on normal thyroid function for neurocognitive and physical development. In the pediatric population, hypothyroidism is frequently categorized as congenital or acquired hypothyroidism, depending on the age of presentation and the underlying etiology. The evaluation and management of children and adolescents with hypothyroidism are determined by the etiology as well as by the age at diagnosis, severity of the hypothyroidism, and the response to thyroid hormone replacement therapy. Children and adolescents require higher weight-based doses for thyroid hormone replacement than do adults, likely due to a shorter half-life of thyroxine (T4) and triiodothyronine (T3) in children, but weight-based dose requirements decrease as the child advances into adulthood. Multiple gaps in knowledge remains regarding how to optimize the treatment of hypothyroidism in pediatric patients, including (but not limited to) the selection of patients with subclinical hypothyroidism for treatment, and the potential benefit of combined LT3/LT4 therapy for patients with persistent symptoms and/or low T3 on LT4 monotherapy. The life-long impact on growth and development, and potentially on long-term cardiovascular and psychosocial health, are significant and highlight the importance of future prospective studies in pediatric patients to explore these areas of uncertainty.

Primary hypothyroidism in a child leads to pituitary hyperplasia: A case report and literature review

RATIONALE

A sellar mass in children is most often seen in craniopharyngeal tumors, intracranial germ cell tumors, or pituitary adenomas. However, pituitary hyperplasia secondary to primary hypothyroidism (PHPH) is not commonly seen in children.

PATIENT CONCERNS

A 10-year-old girl was admitted due to growth retardation and obesity for 4 years. On physical examination, the patient had a height of 118 cm, body weight of 46 kg, body mass index (BMI) of 33.0 kg/m.

DIAGNOSES

After magnetic resonance imaging (MRI) and laboratory tests, her initial diagnosis was Hashimoto's thyroiditis, primary hypothyroidism, and reactive pituitary hyperplasia.

INTERVENTIONS

She was treated with oral L-thyroxine tablets.

OUTCOMES

After 6 months, physical examination showed a height of 125 cm, weight of 36 kg, BMI of 23.0 kg/m. She developed well, with 12 cm of yearly growth thereafter.

LESSONS

The diagnosis of PHPH in a child is very important and sometimes difficult. Based on the summary and analysis of previous cases, we can learn that the main manifestations of PHPH include growth arrest and obesity, perhaps accompanied by symptoms caused by a decreased thyroid hormone concentration and elevated prolactin (PRL) concentration. Intracranial MRI shows diffuse enlargement of the anterior lobe of the pituitary gland, with a dome-shaped blunt edge change. Thyroid hormone levels may decrease, whereas the thyroid stimulating hormone (TSH) level increases, commonly accompanied by an elevated PRL, reduced growth hormone (GH) levels, and positive findings of TPOAb and TGAb. Improvement of symptoms and the normalization of hormone levels as well as restoration of pituitary size can be achieved after treated with thyroid hormone replacement therapy. And a hasty decision on surgical resection should be avoided when the diagnosis is uncertain.

Pituitary hyperplasia: an uncommon presentation of a common disease

A 21-year-old woman presented with amenorrhea, bilateral galactorrhea and fatigue. Visual acuity and visual fields were normal. Laboratory examination demonstrated hyperprolactinemia. Magnetic resonance imaging (MRI) of the pituitary showed a 19×17×12-mm sellar mass with supra- and parasellar extension, causing compression of the pituitary stalk and optic chiasm. Further examinations confirmed mild hyperprolactinemia, strongly elevated TSH (>500 mU/l), low free thyroxine (FT₄), hypogonadotropic hypogonadism and secondary adrenal insufficiency. Hydrocortisone and l-T₄ replacement therapy was started. Three months later, the galactorrhea had disappeared, thyroid function was normalized and MRI revealed regression of the pituitary enlargement, confirming the diagnosis of pituitary hyperplasia (PH) due to primary hypothyroidism. Subsequently, the menstrual cycle returned and the hypocortisolism normalized. This case demonstrates that severe primary hypothyroidism may have an unusual presentation and should be considered in the differential diagnosis of pituitary enlargement associated with moderate hyperprolactinemia.

TSH-Secreting Pituitary Macroadenoma in a Girl with Lingual Thyroid

Patients with long-standing hypothyroid are, in some cases, reported to develop pituitary gland hyperplasia due to loss of feedback inhibition of thyroxine in hypothalamus—the condition of which typically regresses after thyroxine replacement. Herein, a 15-year-old girl—with long-standing untreated lingual hypothyroid—presents with a pathologically proven TSH pituitary macroadenoma and bilateral large ovarian cysts. Although MR imaging may differentiate between hyperplasia and macroadenoma of the pituitary gland, pathological examination is still a cornerstone to correct diagnosis.

Male Child with Van Wyk-Grumbach's Syndrome and Other Complications of Long-Standing Primary Hypothyroidism: A Case Report

Primary hypothyroidism in the juvenile population generally leads to retardation of linear growth and delay or even arrest of puberty. However, in rare conditions, children with long-standing hypothyroidism present with signs of Van Wyk-Grumbach's syndrome (VWGS) which include juvenile hypothyroidism, delayed bone age, and pseudoprecocious puberty. We report a rare case of prepubertal male child from Asian origin, presented with long-standing untreated hypothyroidism complicated with VWGS and other complications including obesity, short stature, hepatomegaly, asymptomatic mild pericardial effusion, and pituitary hyperplasia.

Dermatitis herpetiformis, primary hypothyroidism and pituitary mass mimicking macroadenoma regression after treatment with thyroxin, corticosteroids and dapsone

We report a case of 15-year-old girl who was diagnosed as a case of pituitary macroadenoma on computed tomography and magnetic resonance imaging (MRI) scans for her complains of diminished vision in the left eye and headache. On investigation she was found to have optic atrophy of left eye and primary hypothyroidism. She was started on thyroxin therapy in October 2008 and planned for transcranial excision of the tumor. Just before the date for planned surgery she developed mildly itchy vesico-bullous rash and the surgery was postponed. On histopathology and immunoflourescence studies it was confirmed to be the rash of dermatitis herpetiformis (DH) and treatment was started with corticosteroids in the last week of December 2008 and dapsone was added from mid January 2009. The lesions responded dramatically and within 6 weeks of starting treatment, she had become asymptomatic except for persisting diminution of vision. Repeat MRI scans in mid-February 2009 revealed total regression of pituitary mass. The case is being reported for interesting association of primary hypothyroidism, pituitary mass mimicking macroadenoma and DH; its successful outcome with medical management in the form of total regression of pituitary mass, thereby avoiding an unnecessary surgery.

Nonneoplastic enlargement of the pituitary gland in children

Primary neoplasms of the pituitary gland are uncommon in children. Physiological enlargement of the gland, however, is universal and can sometimes be confused with a tumor. Due to widespread availability of MR imaging, the number of children referred to pediatric neurosurgeons with an enlarged pituitary associated with nonspecific symptoms, most commonly headache, is increasing. In this review, the authors illustrate two common causes of pituitary enlargement in children, namely physiological hypertrophy of puberty, more commonly seen in females, and secondary hyperplasia caused by hypothyroidism. The importance of early and accurate diagnosis, without recourse to extensive endocrine investigations or inappropriate surgery, is underscored.

Pituitary hyperplasia secondary to acquired hypothyroidism: case report

Objective and Importance

despite recent progress in imaging, it is still difficult to distinguish between pituitary adenoma and hyperplasia, even using Magnetic Resonance Imaging (MRI) with gadolinium injection. We describe an example of reactive pituitary hyperplasia from primary hypothyroidism that mimicked a pituitary macroadenoma in a child.

Clinical Presentation

a 10 year old boy presented with headache and statural growth arrest. MRI revealed an intrasellar and suprasellar pituitary mass. Endocrine evaluation revealed primary hypothyroidism.

Intervention

the patient was started on levothyroxine with resolution of the mass effect.

Conclusion

primary hypothyroidism should be considered in the differential diagnosis of solid mass lesions of the pituitary gland. Examination of thyroid function in patients with sellar and suprasellar masses revealed by MRI may avoid unnecessary operations which can cause irreversible complications.

Pituitary hyperplasia in children with short stature and primary hypothyroidism

We present eight cases with short stature, pituitary hyperplasia, and hypothyroidism. Pituitary hyperplasia due to primary hypothyroidism was diagnosed on the basis of clinical manifestations, endocrine examination and MRI. After 2 to 6 months of L-thyroxine replacement therapy, the signs of hypothyroidism disappeared; free triiodothyronine, free thyroxine, thyrotropin and prolactin became normal; and pituitary enlargement regressed. In two children, the growth rate remained low when treated with L-thyroxine, but with additional recombinant human growth hormone (rhGH), the height increased by 11 cm per year. No recurrence of lesions was found on follow-up.