Introduction: Macro-thyroid-stimulating hormone (macro-TSH) is a rare complex formed by monomeric TSH with anti-TSH autoantibodies. Macromolecules of TSH are not renally excreted due to its large size, leading to elevated TSH measurements without clinical consequences. This rare condition frequently mimics subclinical hypothyroidism, often leading to misdiagnosis and inappropriate levothyroxine therapy. Case: A 17-year-old female with major depressive disorder was biochemically diagnosed with subclinical hypothyroidism (TSH 39.06 mIU/L, free thyroxine 4 12.9 pmol/L, antithyroid peroxidase negative) and commenced on levothyroxine. Over 5 years, her TSH levels heavily fluctuated (0.48–82.59 mIU/L) and remained persistently elevated with high-normal free T4 levels despite treatment adherence. An endocrinology consult was obtained, and clinical evaluation revealed a clinically asymptomatic and euthyroid patient, with no family history of thyroid disease or supplement use, and there was no goiter. Assay interference was excluded by analyzing her thyroid function tests on a different platform, which yielded similar biochemical results. Subsequently, a polyethylene glycol (PEG) precipitation test was performed. Her pre-PEG TSH of 29.24 mIU/L decreased significantly to 2.78 mIU/L post-PEG. This yielded a remarkably low TSH recovery rate of 9.5%, strongly indicating the presence of macroTSH. Levothyroxine was then stopped, and she remained clinically euthyroid. Conclusion While gel filtration chromatography remains the gold standard for diagnosing this condition, PEG precipitation is a more accessible, cost-effective, and reliable screening method in clinical practice. A TSH recovery rate below 20% is considered highly suggestive of macro-TSH. Clinicians should maintain a high index of suspicion for macro-TSH in asymptomatic patients presenting with isolated TSH elevations that do not respond to thyroxine therapy. Prompt recognition prevents misdiagnosis and avoids the potential risks of unnecessary thyroid hormone replacement.
Hypothyroidism ; Thyrotropin

Introduction: Isolated hypothyroxinemia (IH) in pregnancy, characterized by low free thyroxine 4 (FT4) with normal thyroidstimulating hormone (TSH), has a reported prevalence of 1.3–8%. We present a diagnostically challenging case that initially mimicked central hypothyroidism before evolving into classic IH. Case: A 37-year-old G4P3 female at 22 + 3 weeks gestation with &beta;-thalassemia trait presented with palpitations and tachycardia (150–184 bpm). A bedside echocardiogram showed volume depletion. Her heart rate improved to 108– 116 bpm following a 1.5 L normal saline bolus. Incidentally, thyroid function tests (TFTs) revealed both low FT4 6.04 pmol/L (7.86–14.41) and low TSH 0.009 mIU/L (0.38–5.33). Anti-thyroid peroxidase antibody was markedly elevated at 360 IU/mL (<35). At 24 + 4 weeks, TFTs showed persistently low FT4 (5.84 pmol/L) and TSH (0.022 mIU/L). Differential diagnoses included central hypothyroidism or assay interference. Tests were repeated using different platforms. Both the Beckman system (FT4: 5.73 pmol/L, TSH: 0.086 mIU/L) and Roche system (FT4: 8.83 pmol/L [12.0–22.0], TSH: 0.11 mIU/L [0.27–4.20]) confirmed low values, ruling out assay interference. Following endocrinology consultation and given her asymptomatic status, IH was considered most likely, and a plan for close monitoring was initiated. Serial follow-up demonstrated biochemical evolution. By 31 + 6 weeks, TFTs showed a low TSH (0.753 mIU/L) with an FT4 level (5.86 pmol/L) within the normal reference range, a pattern typical of IH in pregnancy. Repeat TFTs 6 weeks postpartum showed both TSH and FT4 within normal range. Conclusion This case illustrates a rare and unexpected biochemical progression of IH in pregnancy, initially presenting with a pattern indistinguishable from central hypothyroidism. It underscores that in an asymptomatic, fertile patient, IH can manifest with an atypical pattern early in gestation. The findings suggest that vigilant serial monitoring, rather than immediate extensive pituitary workup, may be a prudent initial approach in such scenarios, as the biochemical profile can normalize toward the classic IH pattern as pregnancy advances.
Female ; Pregnancy ; Thyrotropin

Introduction: Thyroid stimulating hormone (TSH) suppression following differentiated thyroid carcinoma is widely recommended to reduce recurrence risk. However, this strategy assumes cardiovascular tolerance to supraphysiologic thyroid hormone exposure. In patients with advanced structural heart disease, this assumption may fail, exposing a critical limitation of guideline-directed TSH suppression. Case: We report a 71-year-old male with end-stage renal failure on hemodialysis and severe ischemic cardiomyopathy (ejection fraction 23%) who presented with acute decompensation characterized by dyspnea, rapid atrial fibrillation, and non–ST-elevation myocardial infarction. He had a history of papillary thyroid carcinoma treated with total thyroidectomy and radioactive iodine over 20 years prior and was maintained on levothyroxine 200 mcg daily for TSH suppression. Despite biochemically euthyroid indices (TSH 1.8 mIU/L, free thyroxine 4 17 pmol/L), he developed recurrent arrhythmia with heart failure decompensation. This case highlights a dissociation between biochemical euthyroidism and tissue-level thyrotoxicity in a structurally compromised myocardium. Papillary thyroid carcinoma after definitive therapy typically follows an indolent course with low short-term mortality. In contrast, in severe left ventricular dysfunction, excess thyroid hormone increases adrenergic sensitivity and myocardial oxygen demand, precipitating arrhythmia and ischemia. This risk is amplified in end-stage renal disease, where altered hormone handling renders biochemical indices less reliable. Conclusion Biochemical euthyroidism does not equate to physiological safety. In patients with advanced cardiovascular disease, thyroid hormone therapy should be titrated to cardiovascular tolerance rather than oncologic targets alone, and routine TSH suppression may be inappropriate.
Thyroxine ; Heart Failure ; Thyrotropin

Introduction: Discordant thyroid function tests (TFTs), characterized by elevated free thyroxine 4 (FT4) with non-suppressed thyroid-stimulating hormone (TSH), pose a significant diagnostic challenge. Differentiating between Resistance to Thyroid Hormone (RTH) and TSH-secreting pituitary adenoma (TSH-oma) is essential, as management strategies differ substantially. Case: A female with a history of hyperthyroidism diagnosed in 2011 was treated with antithyroid drugs for 1 year before defaulting on follow-up. She was later found to have discordant TFTs at a private centre, where a brain computed tomography scan was reportedly normal. She was referred to our centre for optimization of thyroid function prior to planned thyroidectomy for a solitary large right thyroid nodule measuring 4.2 × 2.8 × 4.7 cm. Fine-needle aspiration cytology demonstrated a benign follicular lesion (Bethesda II). Despite restarting antithyroid medication, she remained clinically euthyroid with no overt thyrotoxic symptoms apart from intermittent palpitations without documented tachycardia. Antithyroid therapy was discontinued. Serial TFTs across multiple assay platforms consistently demonstrated elevated FT4 with inappropriately normal TSH levels. Thyroid autoantibodies, including TSH receptor and anti-thyroid peroxidase antibodies, were negative. Pituitary magnetic resonance imaging showed no evidence of adenoma, and serum &alpha;-subunit level was normal (0.3 ng/ mL), making TSH-oma unlikely. Dynamic testing was not performed as thyrotropin-releasing hormone stimulation was unavailable at our centre, while T3 suppression testing was deemed inappropriate due to symptomatic palpitations. Family screening was not possible as the patient was not in contact with her relatives. In the absence of pituitary pathology and given her largely euthyroid clinical status, RTH was considered the most likely diagnosis. Conclusion This case highlights the importance of considering RTH in patients with persistent discordant TFTs, particularly when clinical findings do not correlate with biochemical abnormalities. Early recognition and appropriate pituitary evaluation are essential to prevent misdiagnosis and avoid unnecessary antithyroid therapy or thyroidectomy.
Pituitary Neoplasms ; Thyroid Hormones ; Thyrotropin

Introduction: Accounting for less than 2% of all pituitary adenomas, TSHsecreting pituitary adenomas (TSHoma) are an uncommon cause of hyperthyroidism. Majority are macroadenomas with delayed diagnosis as most patients are unwittingly treated for primary hyperthyroidism. Recurring discordant thyroid function test (TFT) with elevated thyroidstimulating hormone (TSH) and Free T4 is a hint and warrants additional investigation to facilitate diagnosis. Case: We report a case of a 48-year-old female who was treated for primary hyperthyroidism since her late 20s with multiple admissions for recurrent congestive heart failure and atrial fibrillation. The cardiac issue was preceded by worsening thyrotoxicosis. Previous thyroid autoantibodies were negative. Of note, she had recurring discordant TFT results from two different assays (TSH:84.7, free thyroxine 4 [FT4]:75.43) (TSH:37.86, FT4:27.34) during admission, excluding assay interference and prompting toward TSHoma or Resistance to Thyroid Hormone (RTH). Examination revealed a large goiter (10 × 8 cm) hard in consistency, and pansystolic murmur over tricuspid area. No thyroid eye disease nor bitemporal hemianopia or clinical sign of acromegaly. Echocardiography showed dilated left atrium and mild to moderate tricuspid regurgitation with preserved ejection fraction. Thyroid-releasing hormone (TRH) stimulation test demonstrated blunted TSH response confirming TSHoma. Anterior pituitary hormone profile revealed normal insulin-like growth factor-1 level with suppressed sex hormones and prolactin, thus excluding co-secreting hormone. Sex hormone-binding globulin level, &alpha;-subunit, and T3 suppression test were not done due to unavailability. Magnetic resonance imaging pituitary uncovered pituitary mass measuring (2.6 × 3.3 × 2.2 cm) suggestive of macroadenoma with encasement of cavernous internal carotid arteries and cavernous sinus compression. Computed tomography neck revealed diffuse thyroid enlargement with compressive mass effects onto adjacent structure with trachea narrowing. After discussing with a multidisciplinary team, we planned her for total thyroidectomy followed by transsphenoidal surgery. Conclusion Late presentation and diagnosis in TSHoma remain a major challenge. TFT interpretation is fundamental in identifying the causes of secondary hyperthyroidism to avert detrimental sequalae and to guide optimal treatment.
Atrial Fibrillation ; Thyrotropin

OBJECTIVE: To explore the clinical features and genetic etiology in a child with Hereditary hemorrhagic telangiectasia (HHT) complicated by growth hormone deficiency. METHODS: A child presented at Yantai Yuhuangding Hospital in October 2014 for "short stature for over 4 years" was selected as the study subject. Peripheral venous blood samples were collected from the child and his parents for genomic DNA extraction and whole-exome sequencing (WES). The pathogenicity of the candidate variants was assessed by following the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2025-003). RESULTS: The patient, a 4-year-and-2-month-old male, presented with short stature and recurrent epistaxis since early childhood. Initial diagnosis of GHD was made via growth hormone stimulation testing. During follow-up, telangiectatic macules and polycythemia gradually appeared. WES revealed that he has harbored a heterozygous c.1807G>A (p.Gly603Arg) variant of the ENG gene, which was absent in both parents and classified as likely pathogenic based on ACMG guidelines. Sanger sequencing confirmed the candidate variant to be de novo. CONCLUSION Patients with HHT combined with GHD may exhibit clinical features such as short stature, telangiectasia, and arteriovenous malformations. The heterozygous c.1807G>A (p.Gly603Arg) variant of the ENG gene probably underlay the pathogenesis of the disease in the proband. Above finding has expanded the mutational spectrum of the ENG gene.
Humans ; Telangiectasia, Hereditary Hemorrhagic/complications* ; Male ; Child, Preschool ; Phenotype ; Endoglin/genetics* ; Mutation ; Human Growth Hormone/deficiency* ; Exome Sequencing

OBJECTIVE: To analyze the clinical and genetic characteristics of a Chinese pedigree affected with congenital Isolated growth hormone deficiency (IGHD). METHODS: A pedigree presenting with Pituitary stalk interruption syndrome (PSIS) (including the proband, his two younger sisters and both parents) who had visited the Capital Institute of Pediatrics Affiliated to Capital Medical University in September 2020 was selected as the study subject. Clinical data were collected. Peripheral blood samples were collected from the proband and his family members. Following the extraction of genomic DNA, whole-exome sequencing (WES) was carried out, and candidate variants were validated by Sanger sequencing. The pathogenicity of the candidate variants was classified based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the Institute Pediatrics of Capital Medical University (Ethics No.: SHERLL2025033). RESULTS: The proband and one younger sister (Ⅱ3) presented with growth retardation, short stature, and a doll-like facies. Another younger sister (Ⅱ2) and both parents had normal heights and appearance. Sanger sequencing confirmed that the proband and his younger sister (Ⅱ3) both harbored compound heterozygous variants of the GHRHR gene, namely c.776C>A (p.T259K) and c.1166G>A (p.R389Q). The other younger sister (Ⅱ2) and the parents were heterozygous carriers. The c.1166G>A (p.R389Q) variant was unreported previously. Based on the guidelines from the ACMG, it was classified as variant of uncertain significance (PM2_Supporting+BP4). Bioinformatics analysis indicated a deleterious effect on the protein function. CONCLUSION Variants of the GHRHR gene probably underlay the pathogenesis of IGHD in this pedigree. Above finding has provided a basis for the clinical diagnosis and genetic counseling for this family.
Child ; Female ; Humans ; Male ; China ; Dwarfism, Pituitary/genetics* ; Exome Sequencing ; Human Growth Hormone/deficiency* ; Mutation ; Pedigree ; Receptors, Neuropeptide/genetics* ; Receptors, Pituitary Hormone-Regulating Hormone/genetics* ; East Asian People/genetics*

Varicocele is a prevalent condition in the infertile male population. However, to date, which patients may benefit most from varicocele repair is still a matter of debate. The purpose of this study was to evaluate whether certain preintervention sperm parameters are predictive of successful varicocele repair, defined as an improvement in total motile sperm count (TMSC). We performed a retrospective study on 111 patients with varicocele who had undergone varicocele repair, collected from the Department of Endocrinology, Metabolic Diseases and Nutrition, University of Catania (Catania, Italy), and the Unit of Urology at the Selcuk University School of Medicine (Konya, Türkiye). The predictive analysis was conducted through the use of the Brain Project, an innovative tool that allows a complete and totally unbiased search of mathematical expressions that relate the object of study to the various parameters available. Varicocele repair was considered successful when TMSC increased by at least 50% of the preintervention value. For patients with preintervention TMSC below 5 × 10 6 , improvement was considered clinically relevant when the increase exceeded 50% and the absolute TMSC value was >5 × 10 6 . From the preintervention TMSC alone, we found a model that predicts patients who appear to benefit little from varicocele repair with a sensitivity of 50.0% and a specificity of 81.8%. Varicocele grade and serum follicle-stimulating hormone (FSH) levels did not play a predictive role, but it should be noted that all patients enrolled in this study were selected with intermediate- or high-grade varicocele and normal FSH levels. In conclusion, preintervention TMSC is predictive of the success of varicocele repair in terms of TMSC improvement in patients with intermediate- or high-grade varicoceles and normal FSH levels.
Humans ; Varicocele/complications* ; Male ; Retrospective Studies ; Machine Learning ; Adult ; Treatment Outcome ; Sperm Count ; Infertility, Male/etiology* ; Sperm Motility ; Follicle Stimulating Hormone/blood* ; Young Adult

To investigate the impact of preoperative serum follicle-stimulating hormone (FSH) levels on the probability of testicular sperm retrieval, we conducted a study of nonobstructive azoospermic (NOA) men with different testicular volumes (TVs) who underwent microdissection testicular sperm extraction (micro-TESE). A total of 177 NOA patients undergoing micro-TESE for the first time from April 2019 to November 2022 in Shenzhen Zhongshan Obstetrics and Gynecology Hospital (formerly Shenzhen Zhongshan Urology Hospital, Shenzhen, China) were retrospectively reviewed. The subjects were divided into four groups based on average TV quartiles. Serum hormone levels in each TV group were compared between positive and negative sperm retrieval subgroups. Overall sperm retrieval rate was 57.6%. FSH levels (median [interquartile range]) were higher in the positive sperm retrieval subgroup compared with the negative outcome subgroup when average TV was <5 ml (first quartile [Q1: TV <3 ml]: 43.32 [17.92] IU l -1 vs 32.95 [18.56] IU l -1 , P = 0.048; second quartile [Q2: 3 ml ≤ TV <5 ml]: 31.31 [15.37] IU l -1 vs 25.59 [18.40] IU l -1 , P = 0.042). Elevated serum FSH levels were associated with successful micro-TESE sperm retrieval in NOA men whose average TVs were <5 ml (adjusted odds ratio [OR]: 1.06 per unit increase; 95% confidence interval [CI]: 1.01-1.11; P = 0.011). In men with TVs ≥5 ml, larger TVs were associated with lower odds of sperm retrieval (adjusted OR: 0.84 per 1 ml increase; 95% CI: 0.71-0.98; P = 0.029). In conclusion, elevated serum FSH levels were associated with positive sperm retrieval in micro-TESE in NOA men with TVs <5 ml. In men with TV ≥5 ml, increases in average TVs were associated with lower odds of sperm retrieval.
Humans ; Male ; Azoospermia/surgery* ; Sperm Retrieval/statistics & numerical data* ; Adult ; Follicle Stimulating Hormone/blood* ; Retrospective Studies ; Testis/pathology* ; Microdissection ; Organ Size

Azoospermia, defined as the absence of sperm in the ejaculate, is a well-documented consequence of exogenous testosterone (ET) and anabolic-androgenic steroid (AAS) use. These agents suppress the hypothalamic-pituitary-gonadal (HPG) axis, leading to reduced intratesticular testosterone levels and impaired spermatogenesis. This review examines the pathophysiological mechanisms underlying azoospermia and outlines therapeutic strategies for recovery. Azoospermia is categorized into pretesticular, testicular, and post-testicular types, with a focus on personalized treatment approaches based on the degree of HPG axis suppression and baseline testicular function. Key strategies include discontinuing ET and monitoring for spontaneous recovery, particularly in patients with shorter durations of ET use. For cases of persistent azoospermia, gonadotropins (human chorionic gonadotropin [hCG] and follicle-stimulating hormone [FSH]) and selective estrogen receptor modulators (SERMs), such as clomiphene citrate, are recommended, either alone or in combination. The global increase in exogenous testosterone use, including testosterone replacement therapy and AAS, underscores the need for improved management of associated azoospermia, which can be temporary or permanent depending on individual factors and the type of testosterone used. Additionally, the manuscript discusses preventive strategies, such as transitioning to short-acting testosterone formulations or incorporating low-dose hCG to preserve fertility during ET therapy. While guidelines for managing testosterone-related azoospermia remain limited, emerging research indicates the potential efficacy of hormonal stimulation therapies. However, there is a notable lack of well-structured, controlled, and long-term studies addressing the management of azoospermia related to exogenous testosterone use, highlighting the need for such studies to inform evidence-based recommendations.
Humans ; Azoospermia/therapy* ; Male ; Testosterone/therapeutic use* ; Anabolic Agents/adverse effects* ; Clomiphene/therapeutic use* ; Chorionic Gonadotropin/therapeutic use* ; Follicle Stimulating Hormone/therapeutic use* ; Spermatogenesis/drug effects* ; Androgens/adverse effects*