Summary

Hepatocyte nuclear factor 1β (HNF1B) gene is located on chromosome 17q12. It is a transcription factor implicated in the early embryonic development of multiple organs. HNF1B-associated disease is a multi-system disorder with variable clinical phenotypes. There are increasing reports suggesting that the 17q12 deletion syndrome should be suspected in patients with maturity-onset diabetes of the young type 5 (MODY5) due to the deletion of HNF1B gene. In contrast to classical 17q12 syndrome in childhood with neurological disorders and autism, patients with HNF1B-MODY deletion rarely had neuropsychological disorders or learning disabilities. The diagnosis of 17q12 deletion syndrome highlighted the phenotypic heterogeneity of HNF1B-MODY patients. In this study, we report the clinical course of a Thai woman with young-onset diabetes mellitus and hypertriglyceridemia as a predominant feature due to HNF1B deletion as part of the 17q12 deletion syndrome. Our findings and others suggest that hypertriglyceridemia should be considered a syndromic feature of HNF1B-MODY. Our case also highlights the need to use sequencing with dosage analyses to detect point mutations and copy number variations to avoid missing a whole deletion of HNF1B.

Learning points

• Maturity-onset diabetes of the young type 5 (MODY5) may be caused by heterozygous point mutations or whole gene deletion of HNF1B. Recent studies revealed that complete deletion of the HNF1B gene may be part of the 17q12 deletion syndrome with multi-system involvement.

• The length of the deletion can contribute to the phenotypic variability in patients with HNF1B-MODY due to whole gene deletion.

• Using next-generation sequencing alone to diagnose MODY could miss a whole gene deletion or copy number variations. Specialized detection methods such as microarray analysis or low-pass whole genome sequencing are required to accurately diagnose HNF1B-MODY as a component of the 17q12 deletion syndrome.

• Molecular diagnosis is necessary to distinguish other acquired cystic kidney diseases in patients with type 2 diabetes which could phenocopy HNF1B-MODY.

• Hypertriglyceridemia is a possible metabolic feature in patients with HNF1B-MODY due to 17q12 deletion syndrome.

Summary

Graves’ disease is an autoimmune condition leading to the activation of and an increase in thyroid hormone secretion. Manifestations of hyperthyroidism in Graves’ disease can vary among people. In this case, we report a 24-year-old Thai man with a rare presentation of unilateral gynecomastia along with symptoms of thyrotoxicosis. Physical examination revealed a 3 cm non-tender palpable glandular tissue beneath and around the left areola without nipple discharge and moderately diffuse thyroid enlargement with thyroid bruit. Thyroid function test showed a typical thyrotoxicosis state with elevated serum-free T4 and decreased serum TSH. His diagnosis of Graves’ disease was confirmed biochemically with a highly elevated anti-TSH receptor antibody. Early treatment with anti-thyroid medication was given first, followed by Radioiodine treatment (RAI) for definitive treatment due to high level of anti-TSH receptor antibody, enlarged thyroid and severe thyrotoxicosis presentation at a young age, which might not resolve by anti-thyroid medication alone. The patient responded well to treatment and achieved complete resolution of unilateral gynecomastia with clinically and biochemically euthyroid within 3 months after treatment. No recurrent gynecomastia was found during the 2-year follow-up.

Learning points

• Characteristic of gynecomastia in hyperthyroidism is usually presented with bilateral progressive gynecomastia; however, unilateral gynecomastia is occasionally found as a presentation of hyperthyroidism.

• Complete resolution of gynecomastia without recurrence can be achieved within a few months of treatment after thyrotoxicosis is resolved in patients with hyperthyroidism with the recent development of gynecomastia.

• RAI for definitive treatment is recommended in young adult patients expressing very high anti-TSH antibody level with severe thyrotoxicosis.

Summary

Ectopic adrenocorticotropic hormone (ACTH) secretion is responsible for 5–15% of Cushing’s syndrome (CS). Neuroendocrine tumor (NET) is a common cause of ectopic ACTH syndrome (EAS). However, primary renal NET is exceedingly rare. Fewer than 100 cases have been reported and only a few cases presented with CS. Because of its rarity and lack of long-term follow-up data, clinical manifestations, biological behavior and prognosis are not well understood. Here, we report the case of a 51-year-old man who presented with clinical and laboratory findings compatible with EAS. CT scan revealed a lesion of uncertain nature at the lower pole of the left kidney. Octreotide scan found a filling defect at the lower pole of left kidney. It was difficult to determine if this finding was the true etiology or an incidental finding. Unfortunately, the patient’s clinical status rapidly deteriorated with limited medical treatment. The patient underwent left nephrectomy and left adrenalectomy. Histopathological examination confirmed NET with oncocytic features. Immunohistochemistry staining was positive for ACTH. The patient’s condition gradually improved. Additionally, glucocorticoid replacement was required only 6 months during a gradual recovery of hypothalamic pituitary adrenal axis achieved approximately three years after tumor removal. Although extremely rare, primary renal NET should be considered as a cause of EAS particularly in a patient with rapid clinical deterioration. Thorough investigation, early diagnosis and careful management are crucial to reduce morbidity and mortality.

Learning points

• Primary renal NET is an extremely rare cause of ectopic ACTH syndrome.

• Ectopic ACTH syndrome has a rapid onset with severe clinical manifestations. In this case, the patient’s condition deteriorated rapidly, resulting from severe hypercortisolism. Resection of the tumor is the most effective treatment.

• Localization of ectopic ACTH-secreting tumors is very challenging. Multimodality imaging including CT, MRI, octreotide scan, and positron emission tomography plays a crucial role in identifying the tumors. However, each imaging modality has limitations.

Summary

In this case report, we describe a 37-year-old male who presented with fever and tender neck mass. Neck ultrasonography revealed a mixed echogenic multiloculated solid-cystic lesion containing turbid fluid and occupying the right thyroid region. Thyroid function tests showed subclinical hyperthyroidism. The patient was initially diagnosed with thyroid abscess and he was subsequently treated with percutaneous aspiration and i.v. antibiotics; however, his clinical symptoms did not improve. Surgical treatment was then performed and a pathological examination revealed a ruptured epidermoid cyst with abscess formation. No thyroid tissue was identified in the specimen. The patient was discharged uneventfully. However, at the 3-month and 1-year follow-ups, the patient was discovered to have developed subclinical hypothyroidism. Neck ultrasonography revealed a normal thyroid gland. This report demonstrates a rare case of epidermoid cyst abscess in the cervical region, of which initial imaging and abnormal thyroid function tests led to the erroneous diagnosis of thyroid abscess.

Learning points:

• Epidermoid cyst abscess at the cervical region can mimic thyroid abscess.

• Neck ultrasonography cannot distinguish thyroid abscess from epidermoid cyst abscess.

• Thyroid function may be altered due to the adjacent soft tissue inflammation.

Summary

Primary amenorrhea could be caused by disorders of four parts: disorders of the outflow tract, disorders of the ovary, disorders of the anterior pituitary, and disorders of hypothalamus. Delay in diagnosis and hormone substitution therapy causes secondary osteoporosis. Herein, we report a case of a 23-year-old phenotypical female who presented with primary amenorrhea from 46, XX gonadal dysgenesis but had been misdiagnosed as Mayer–Rokitansky–Kuster–Hauser (MRKH) syndrome or Mullerian agenesis. The coexistence of gonadal dysgenesis and MRKH was suspected after laboratory and imaging investigations. However, the vanishing uterus reappeared after 18 months of hormone replacement therapy. Therefore, hormone profiles and karyotype should be thoroughly investigated to distinguish MRKH syndrome from other disorders of sex development (DSD). Double diagnosis of DSD is extremely rare and periodic evaluation should be reassessed. This case highlights the presence of estrogen deficiency state, the uterus may remain invisible until adequate exposure to exogenous estrogen.

Learning points:

• An early diagnosis of disorders of sex development (DSD) is extremely important in order to promptly begin treatment, provide emotional support to the patient and reduce the risks of associated complications.

• Hormone profiles and karyotype should be investigated in all cases of the presumptive diagnosis of Mayer–Rokitansky–Kuster–Hauser (MRKH) syndrome or Mullerian agenesis.

• The association between 46, XX gonadal dysgenesis and Mullerian agenesis has been occasionally reported as a co-incidental event; however, reassessment of the presence of uterus should be done again after administration of exogenous estrogen replacement for at least 6–12 months.

• A multidisciplinary approach is necessary for patients presenting with DSD to ensure appropriate treatments and follow-up across the lifespan of individuals with DSD.