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Open access

C Kamath, J Witczak, M A Adlan and L D Premawardhana

Summary

Thymic enlargement (TE) in Graves’ disease (GD) is often diagnosed incidentally when chest imaging is done for unrelated reasons. This is becoming more common as the frequency of chest imaging increases. There are currently no clear guidelines for managing TE in GD. Subject 1 is a 36-year-old female who presented with weight loss, increased thirst and passage of urine and postural symptoms. Investigations confirmed GD, non-PTH-dependent hypercalcaemia and Addison’s disease (AD). CT scans to exclude underlying malignancy showed TE but normal viscera. A diagnosis of hypercalcaemia due to GD and AD was made. Subject 2, a 52-year-old female, was investigated for recurrent chest infections, haemoptysis and weight loss. CT thorax to exclude chest malignancy, showed TE. Planned thoracotomy was postponed when investigations confirmed GD. Subject 3 is a 47-year-old female who presented with breathlessness, chest pain and shakiness. Investigations confirmed T3 toxicosis due to GD. A CT pulmonary angiogram to exclude pulmonary embolism showed TE. The CT appearances in all three subjects were consistent with benign TE. These subjects were given appropriate endocrine treatment only (without biopsy or thymectomy) as CT appearances showed the following appearances of benign TE – arrowhead shape, straight regular margins, absence of calcification and cyst formation and radiodensity equal to surrounding muscle. Furthermore, interval scans confirmed thymic regression of over 60% in 6 months after endocrine control. In subjects with CT appearances consistent with benign TE, a conservative policy with interval CT scans at 6 months after endocrine control will prevent inappropriate surgical intervention.

Learning points:

  • Chest imaging is common in modern clinical practice and incidental anterior mediastinal abnormalities are therefore diagnosed frequently.

  • Thymic enlargement (TE) associated with Graves’ disease (GD) is occasionally seen in view of the above.

  • There is no validated strategy to manage TE in GD at present.

  • However, CT (or MRI) scan features of the thymus may help characterise benign TE, and such subjects do not require thymic biopsy or surgery at presentation.

  • In them, an expectant ‘wait and see’ policy is recommended with GD treatment only, as the thymus will show significant regression 6 months after endocrine control.

Open access

Lukas Burget, Laura Audí Parera, Monica Fernandez-Cancio, Rolf Gräni, Christoph Henzen and Christa E Flück

Summary

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.

Learning points:

  • 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.