were documented from March 2016 to March 2017, as were insulin intake and activity levels. BG readings (mmol/L) were recorded using her Freestyle Libre and a Bayer Contour Next monitor. HbA1c values (mmol/mol) were obtained from routine clinical
Mirjam Eiswirth, Ewan Clark and Michael Diamond
Adam R Puchalski and Inder J Chopra
Radioiodine (131I) is a critical component in the treatment of differentiated thyroid cancer. We recently saw a patient with thyroid cancer who was hesitant to take 131I treatment because he had previously encountered an allergic reaction to administration of iodine-containing radiocontrast agent for computed tomography (CT) scanning. We were able to administer 131I treatment after discussion that his anaphylactic reaction was not due to iodine and that radioiodine (131I) treatment is unlikely to cause a reaction in the patient.
- An allergy to iodine itself does not exist.
- When patients claim that they have an ‘iodine allergy’, ask them what substances they are allergic to and what kind of reaction occurred during use of such substances.
- Radioactive iodine is not a contraindication for patients who claim an ‘allergy to iodine’.
Dinesh Giri, Federico Roncaroli, Ajay Sinha, Mohammed Didi and Senthil Senniappan
Corticotroph adenomas are extremely rare in children and adolescents. We present a 15-year-old boy who was investigated for delayed puberty (A1P2G1, bilateral testicular volumes of 3 mL each). There was no clinical or laboratory evidence suggestive of chronic illness, and the initial clinical impression was constitutional delay in puberty. Subsequently, MRI scan of the brain revealed the presence of a mixed cystic and solid pituitary lesion slightly displacing the optic chiasma. The lesion was removed by transphenoidal surgery and the biopsy confirmed the lesion to be pituitary adenoma. Furthermore, the adenoma cells also had Crooke’s hyaline changes and were intensely positive for ACTH. However there was no clinical/biochemical evidence of ACTH excess. There was a spontaneous pubertal progression twelve months after the surgery (A2P4G4, with bilateral testicular volume of 8 mL). Crooke’s cell adenoma is an extremely rare and aggressive variant of corticotroph adenoma that can uncommonly present as a silent corticotroph adenoma in adults. We report for the first time Crooke’s cell adenoma in an adolescent boy presenting with delayed puberty.
- Constitutional delay of growth and puberty (CDGP) is a diagnosis of exclusion; hence a systematic and careful review should be undertaken while assessing boys with delayed puberty.
- Crooke’s cell adenomas are a group of corticotroph adenomas that can rarely present in childhood and adolescence with delayed puberty.
- Crooke’s cell adenomas can be clinically silent but are potentially aggressive tumours that require careful monitoring.
María Clemente, Alejandro Vargas, Gema Ariceta, Rosa Martínez, Ariadna Campos and Diego Yeste
HNF4A gene mutations have been reported in cases of transient and persistent hyperinsulinaemic hypoglycaemia of infancy (HHI), particularly in families with adulthood diabetes. The case of a patient with HHI, liver impairment and renal tubulopathy due to a mutation in HNF4A is reported.
- Urine specimen study in cases of HHI with diazoxide response is necessary to rule out specific metabolic conditions (l-3-hydroxyacyl-coenzyme A dehydrogenase deficiency) or tubular renal involvement.
- Hyperinsulinaemic hypoglycaemia due to the heterozygous mutation (p.Arg63Trp, c. 187C > T) in the HNF4A gene is associated with renal tubulopathy and liver involvement.
- Follow-up of patients diagnosed of HHI is mandatory to detect associated conditions.
C E Stiles, R Thuraisingham, D Bockenhauer, L Platts, A V Kumar and M Korbonits
29-year-old female presenting with an 8-year history of unexplained hypomagnesaemia, which was severe enough to warrant intermittent inpatient admission for intravenous magnesium. Urinary magnesium was inappropriately normal in the context of hypomagnesaemia indicating magnesium wasting. Ultrasound imaging demonstrated unilateral renal cysts and computed tomography of kidneys, ureters and bladder showed a bicornuate uterus. Referral to genetic services and subsequent testing revealed a de novo HNF1B deletion.
- HNF1B loss-of-function mutations are one of the most common monogenic causes of congenital anomalies of the kidney and urinary tract.
- Those with HNF1B mutations may have some of a constellation of features (renal and hepatic cysts, deranged liver function tests, maturity onset diabetes of the young type 5 (MODY5), bicornuate uterus, hyperparathyroidism, hyperuricaemic gout, but presenting features are highly heterogeneous amongst patients and no genotype/phenotype correlation exists.
- HNF1B mutations are inherited in an autosomal dominant pattern but up to 50% of cases are de novo.
- HNF1B mutations can be part of the Chr17q12 deletion syndrome, a contiguous gene deletion syndrome.
- Inorganic oral magnesium replacements are generally poorly tolerated with side effects of diarrhoea. Organic magnesium compounds, such as magnesium aspartate, are better absorbed oral replacement therapies.
Caroline Bachmeier, Chirag Patel, Peter Kanowski and Kunwarjit Sangla
Primary hyperparathyroidism (PH) is a common endocrine abnormality and may occur as part of a genetic syndrome. Inactivating mutations of the tumour suppressor gene CDC73 have been identified as accounting for a large percentage of hyperparathyroidism-jaw tumour syndrome (HPT-JT) cases and to a lesser degree account for familial isolated hyperparathyroidism (FIHP) cases. Reports of CDC73 whole gene deletions are exceedingly rare. We report the case of a 39 year-old woman with PH secondary to a parathyroid adenoma associated with a large chromosomal deletion (2.5 Mb) encompassing the entire CDC73 gene detected years after parathyroidectomy. This case highlights the necessity to screen young patients with hyperparathyroidism for an underlying genetic aetiology. It also demonstrates that molecular testing for this disorder should contain techniques that can detect large deletions.
- Necessity of genetic screening for young people with hyperparathyroidism.
- Importance of screening for large, including whole gene CDC73 deletions.
- Surveillance for patients with CDC73 gene mutations includes regular calcium and parathyroid hormone levels, dental assessments and imaging for uterine and renal tumours.
Naweed Alzaman, Anastassios G Pittas, Miriam O'Leary and Lisa Ceglia
Transient hypocalcemia after thyroidectomy is not uncommon and the risk increases with the extent of neck surgery. We report a case of severe and prolonged hypocalcemia after total thyroidectomy complicated by thoracic duct injury. Hypoparathyroidism and thoracic duct injury are potential complications following total thyroidectomy with extensive lymph node dissection. This case suggested that having both conditions may complicate treatment of hypoparathyroid-induced hypocalcemia by way of losses of calcium and vitamin D in the chyle leak.
- This report highlights chyle leak as an uncommon cause of prolonged hypocalcemia in patients who have undergone extensive neck surgery.
- Chyle has an electrolyte concentration similar to that of plasma.
- Medical treatment options for a chyle leak include fat-free oral diet or parenteral nutrition without oral intake, pharmacological treatment (primarily octreotide).
Jill Pancer, Elliot Mitmaker, Oluyomi Ajise, Roger Tabah and Jacques How
Multifocal papillary thyroid carcinoma (PTC) is common and the number of tumor foci rarely exceeds ten. The mechanism of multifocal disease is debated, with the two main hypotheses consisting of either intrathyroidal metastatic spread from a single tumor or independent multicentric tumorigenesis from distinct progenitor cells. We report the case of a 46-year-old woman who underwent total thyroidectomy and left central neck lymph node dissection after fine-needle aspiration of bilateral thyroid nodules that yielded cytological findings consistent with PTC. Final pathology of the surgical specimen showed an isthmic dominant 1.5 cm classical PTC and over 30 foci of microcarcinoma, which displayed decreasing density with increasing distance from the central lesion. Furthermore, all malignant tumors and lymph nodes harbored the activating BRAF V600E mutation. The present case highlights various pathological features that support a mechanism of intraglandular spread, namely a strategic isthmic location of the primary tumor, radial pattern of distribution and extensive number of small malignant foci and BRAF mutational homogeneity.
- Multifocal papillary thyroid carcinoma (PTC) is commonly seen in clinical practice, but the number of malignant foci is usually limited to ten or less.
- There is no clear consensus in the literature as to whether multifocal PTC arises from a single or multiple distinct tumor progenitor cells.
- Strategic location of the dominant tumor in the thyroid isthmus may favor intraglandular dissemination of malignant cells by means of the extensive lymphatic network.
- An important pathological finding that may be suggestive of intrathyroidal metastatic spread is a central pattern of distribution with a reduction in the density of satellite lesions with increasing distance from the dominant focus.
- PTCs originating from the isthmus with intraglandular metastatic dissemination behave more aggressively. As such, a more aggressive treatment course may be warranted, particularly with regard to the extent of surgery.
Lukas Burget, Laura Audí Parera, Monica Fernandez-Cancio, Rolf Gräni, Christoph Henzen and Christa E Flück
Steroidogenic acute regulatory protein (STAR) is a key protein for the intracellular transport of cholesterol to the mitochondrium in endocrine organs (e.g. adrenal gland, ovaries, testes) and essential for the synthesis of all steroid hormones. Several mutations have been described and the clinical phenotype varies strongly and may be grouped into classic lipoid congenital adrenal hyperplasia (LCAH), in which all steroidogenesis is disrupted, and non-classic LCAH, which resembles familial glucocorticoid deficiency (FGD), which affects predominantly adrenal functions. Classic LCAH is characterized by early and potentially life-threatening manifestation of primary adrenal insufficiency (PAI) with electrolyte disturbances and 46,XY disorder of sex development (DSD) in males as well as lack of pubertal development in both sexes. Non-classic LCAH manifests usually later in life with PAI. Nevertheless, life-long follow-up of gonadal function is warranted. We describe a 26-year-old female patient who was diagnosed with PAI early in life without detailed diagnostic work-up. At the age of 14 months, she presented with hyperpigmentation, elevated ACTH and low cortisol levels. As her older brother was diagnosed with PAI two years earlier, she was put on hydrocortisone and fludrocortisone replacement therapy before an Addisonian crisis occurred. Upon review of her case in adulthood, consanguinity was noted in the family. Genetic analysis for PAI revealed a homozygous mutation in the STAR gene (c.562C>T, p.Arg188Cys) in both siblings. This mutation has been previously described in non-classic LCAH. This case illustrates that early onset, familial PAI is likely due to autosomal recessive genetic mutations in known genes causing PAI.
- In childhood-onset PAI, a genetic cause is most likely, especially in families with consanguinity.
- Adult patients with an etiologically unsolved PAI should be reviewed repeatedly and genetic work-up should be considered.
- Knowing the exact genetic diagnosis in PAI is essential for genetic counselling and may allow disease-specific treatment.
- Young men and women with NCLAH due to homozygous STAR Arg188Cys mutation should be investigated for their gonadal function as hypogonadism and infertility might occur during puberty or in early adulthood.
Anil Piya, Jasmeet Kaur, Alan M Rice and Himangshu S Bose
Cholesterol transport into the mitochondria is required for synthesis of the first steroid, pregnenolone. Cholesterol is transported by the steroidogenic acute regulatory protein (STAR), which acts at the outer mitochondrial membrane prior to its import. Mutations in the STAR protein result in lipoid congenital adrenal hyperplasia (CAH). Although the STAR protein consists of seven exons, biochemical analysis in nonsteroidogenic COS-1 cells showed that the first two were not essential for pregnenolone synthesis. Here, we present a patient with ambiguous genitalia, salt-lossing crisis within two weeks after birth and low cortisol levels. Sequence analysis of the STAR, including the exon–intron boundaries, showed the complete deletion of exon 1 as well as more than 50 nucleotides upstream of STAR promoter. Mitochondrial protein import with the translated protein through synthesis cassette of the mutant STAR lacking exon 1 showed protein translation, but it is less likely to have synthesized without a promoter in our patient. Thus, a full-length STAR gene is necessary for physiological mitochondrial cholesterol transport in vivo.
- STAR exon 1 deletion caused lipoid CAH.
- Exon 1 substitution does not affect biochemical activity.
- StAR promoter is responsible for gonadal development.